Carman scan for            EMS professor
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Carman scan for EMS professor. Contents. 1. Scope Meter Utilization 2. Application of Ignition Secondary Wave 3. Multi-meter Utilization 4. Application of Simulation Function 5. Application of Special Maintenance 6. Carman scan Utilization Chart. 1. Scope Meter Utilization.

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Carman scan for ems professor

Carman scan for EMS professor


Carman scan for ems professor

Contents

1. Scope Meter Utilization

2. Application of Ignition Secondary Wave

3. Multi-meter Utilization

4. Application of Simulation Function

5. Application of Special Maintenance

6. Carman scan Utilization Chart


Carman scan for ems professor

1. Scope Meter Utilization

1.1 Crank Angle Sensor Signal Analysis

1.2 CAM Angle Sensor Signal Analysis

1.3 TPS Signal Analysis

1.4 Air Flow Sensor Signal Analysis

1.5 O2 Sensor Signal Analysis

1.6 Injector Signal Analysis

1.7 Ignition System Analysis

1.8 ISC Valve Signal Analysis

1.9 Air Temp. Sensor Signal Analysis

1.10 Knock Sensor Signal Analysis

1.11 Vehicle Speed Sensor Signal Analysis

1.12 EGR Valve Signal Analysis

1.13 Purge Valve Signal Analysis

1.14 O2 Sensor Heater Signal Analysis


Carman scan for ems professor

About

Sensor

1.1 Crank angle sensor signal analysis

1.1.1 Introduction of crank angle sensor and principle (1/2)

Crank angle sensor is a sensor for locating piston by ECU and necessary to find ignition time .

If the signal of the crank angle sensor keeps its consistency, then it is hard to find starting and ending point. Therefore, two teeth are taken out from the crank and it is called Long Tooth and the rest are called Short Tooth. By using long Tooth, TDC ( Top Dead Center ) is found.

Contents shown by signal of crank sensor.

1. Ignition time = 360deg * Number of tooth before TDC / Number of tooth at one revolution of engine.

Ignition time is calculated by number of tooth between the long tooth and peak voltage. Peak voltage is obtained by measuring signal of crank angle sensor and primary ignition wave simultaneously.

2. Engine speed (RPM) = 60 / ( Time between long tooth * Number of long tooth at one revolution of engine)

RPM is calculated by number of long tooth at one revolution of engine.


Carman scan for ems professor

Sensor type

Algorithm

Magnetic type

1.1.1 Introduction of crank angle sensor and principle (2/2)

Three mostly used crank angle sensor.

1. Optical Sensor : The sensor is used on a single-bodied cam shaft with a hole on the disk. The signal is recognized when the signal passes through the hole while the disk is revolving. This particular sensor is destructive by heat and humidity and makes lots of noise. ( This is the only sensor that disk for crank angle sensor revolve 1 revolution while crank shaft rotate 2 revolution. )

2. Magnetic Sensor : If the electromagnetic power generated by coil is intercepted by revolution of a single-bodied camshaft with target wheel (normally outside of flywheel ), then the voltage is generated. The sensor is using this voltage for signal..

3. Hall type sensor : The circuit is included in the sensor inside. This sensor electron The circuit included inside the sensor discharge the electron. The single bodied crank shaft with target wheel (normally outside of fly wheel ) disturbs discharging of electron and generate the voltage. This voltage is used for signal.

Optical type

Optical type

Magnetic type sensor signal

This sensor is the most important sensor for the ECU. If sporadic engine stall happened , then suspect this sensor at first.

1. If the ECU detects fault on this signal, then the ECU stop “fuel injection and ignition

2. If the ECU could not detect fault signal, then normal component or not equipped component might be detected as a fault one.


Carman scan for ems professor

Sensor repair info view.

Data analysis

Normal value

About sensor

1.1.2 The Methodology of Crank Angle Sensor Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Vehicle selection System(Engine / Transmission / ABS …)Crank Sensor  Measuring


Carman scan for ems professor

Malfunction of Crank Angle Sensor (1/2)

Cause of trouble

Troubles

1. Malfunction of crank angle sensor or wiring circuit failure

(Signal, Ground and Reference line)

2. Bad connection of wiring

3. Cut off noise or remove cause of noise from crank angle sensor

3.1 Shield crank angle sensor wiring.

3.2 Check whether spark plug is original part or not

(Resistance range : 2.0 - 4.5K)

4. The counteraction of sensor maker should be required.

1. The signal is always high or low.

2. The signal is intermittently missed.

3. The noise signal detection.

4. The signal is normal but ECU identify wrong crank angle signal.

Engine state

1. The engine is not started.

2. The engine vibration and stall are sometimes occurred.

3. The engine vibration and stall are sometimes occurred and display DTC of

normal part or non existed part

4. The ignition timing is out of control range.

Normal signal

1.1.3 Crank Angle Sensor Trouble type and Analysis (1/2)


Carman scan for ems professor

Malfunction of Crank Angle Sensor (2/2)

Signal wave when trouble detection

1.1.3 Crank Angle Sensor Trouble type and Analysis (2/2)

1. Always constant signal

2. Intermittently signal missing

4. Signal is normal but ECU wrong identification

3. The noise signal detection

Ignition timing from scanner is different with calculation from signal.


Carman scan for ems professor

1.Field example of Crank angle sensor trouble:ECU wrong identification

Cause of trouble

Trouble

ECU identified wrong crank angle signal and it led to wrong calculation of ignition timing. So, ECU started ignition with suction stroke.

Accent 2000MY vehicle is started with hesitation.

Related vehicles

This phenomenon is frequently occurred with magnetic crank angle sensor.

Accent 2000MY, Avante 1.5L/1.8L DOHC, Tiburon, Verna

Signal view

1.1.4 Crank Angle Sensor Field Service Example (1/2)

Ignition was BTDC 12deg on scanner but calculation from measured signal was ATDC 48deg. TDC position was identified from service information of Carman scan.


Carman scan for ems professor

2.Field example of Crank angle sensor trouble:Intermittently signal missing

Cause of trouble

Trouble

Crank angle signal was abnormal due to power cut when key release.

HMC Sonata 2,3(1.8/2.0L DOHC MAP)vehicle : Vehicle is started with hesitation in cold ambient condition or don’t start.

Related vehicles

This phenomenon is frequently occurred with optical crank angle sensor(MELCO 52 pin ECU).

New Sonata 2,3(1.8/2.0 DOHC), New grandeur etc.

Signal view

1.1.4 Crank Angle Sensor Field Service Example (2/2)

If you measure crank angle signal with above phenomenon, you can see abnormal crank signal.It result in injection cut off.


Carman scan for ems professor

About Sensor

1.2 CAM angle sensor signal analysis

1.2.1 Introduction of cam angle sensor and principle(1/2)

CAM angle sensor is the sensor to indicate the TDC of each cylinders by ECU. This sensor is necessary to calculate injection phase. We can calculate TDC from the crank angle sensor but cylinder number. Therefore ECU recognize the TDC right after cam angle signal. ECU use the cam signal located between two long tooth. If the signal of cam is located inside the long tooth, then ECU detects it as a fault.

TDC

19th

TDC shown after CAM signal is the first TDC.

Information from the signal of cam sensor : TDC of the1st cylinder


Carman scan for ems professor

About Sensor

Algorithm

Optical / hall type sensor signal

Magnetic type sensor signal

1.2.1 Introduction of cam angle sensor and principle(2/2)

Three mostly used cam angle sensor.

1. Optical Sensor : The sensor is used on a single-bodied cam shaft with a hole on the disk. The signal is recognized when the signal passes through the hole while the disk is revolving. This particular sensor is destructive by heat and humidity and makes lots of noise. ( This is the only sensor that disk for crank angle sensor revolve 2 revolution while crank shaft rotate 1 revolution. )

2. Magnetic Sensor : If the electromagnetic power generated by coil is intercepted by revolution of a single-bodied camshaft with target wheel (normally outside of flywheel ), then the voltage is generated. The sensor is using this voltage for signal.

3. Hall type sensor : The circuit is included in the sensor inside. This sensor electron The circuit included inside the sensor discharge the electron. The single bodied crank shaft with target wheel (normally outside of fly wheel ) disturbs discharging of electron and generate the voltage. This voltage is used for signal

In order to reduce the emission, injection should be finished before intake valve open. If the fuel is injected on the hot intake valve, then fuel is well vaporized and this helps good combustion.

Therefore, cam signal is used to identify the cylinder number.

In case of no spark time adjustment type,we can know it by comparing cam signal position with crank angle sensor.


Carman scan for ems professor

1.2.2 The Methodology of Camshaft Angle Sensor Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Vehicle selectionSystem(ENG)CAM Part(F4 key)  Measuring

Remark : Since both A and B channels can be used at the same time, it is better to measure crank and cam angle signal simultaneously.

Sensor repair info view

Normal valve

About sensor

Data analysis


Carman scan for ems professor

Malfunction of Camshaft Angle Sensor(1/2)

Cause of trouble

Trouble

1. Malfunction of CAM angle sensor or wiring circuit failure

(Signal, Ground and Reference line)

2. Check valve timing. If it is not proper, please adjust it.

3. Cut off noise or remove cause of noise from CAM angle sensor

3.1 Shield CAM angle sensor wiring.

3.2 Check whether spark plug is original part or not

(Resistance range : 2.0 - 4.5K)

1. The signal is always high or low.

2. The signal is intermittently missed(Invalid signal detection during 1 cycle).

3. The noise signal detection.

Engine state

1. The engine problem is not occurred but GDI engine is not started.

2. CAM sensor error is intermittently detected with poor acceleration.

3. The engine vibration and stall are sometimes occurred and display DTC of

normal part or non existed part

4. The ignition timing is out of control range and in case of LPG vehicle

back-fire is occurred.

Normal signal

1.2.3 Camshaft Angle Sensor Trouble type and Analysis (1/2)

Upper signal in picture is CAM signal and sine signal is crank signal.


Carman scan for ems professor

Malfunction of Camshaft Angle Sensor (2/2)

Signal wave when trouble detection

1.2.3 Camshaft Angle Sensor Trouble type and Analysis (2/2)

1. Always constant signal

3. The noise signal detection

Avante, XG use this signal

2. Intermittently signal missing

(CAM signal detection in long tooth duration:This is normal with Avante XD)


Carman scan for ems professor

Field example of CAM angle sensor trouble : Case of CAM signal delay

Cause of trouble

Trouble

Ignition was retarded (about 9[deg]) due to wrong valve timing and CAM signal is detected just before long tooth.

Avante DOHC vehicle is not accelerated and CAM error is sometimes detected.

Related vehicles

This phenomenon is occurred when CAM signal is identified before long tooth.

Signal view

1.2.4 Camshaft Angle Sensor Field Service Example

CAM signal was identified before long tooth but distance between CAM signal and long tooth was not over 1 tooth.

The valve timing was wrong adjusted as 1 tooth.

< Reference > The valve timing can be fast or delay by tensioner moving when acce

leration

Before valve timing adjustment

After valve timing adjustment


Carman scan for ems professor

TPS

About Sensor

Sensor type

Algorithm

1.3 Throttle Position Sensor (TPS) signal analysis

1.3.1 Introduction of TPS and principle

TPS is the sensor to know how much accelerate the acceleration pedal. If the line of this sensor is broken, then more than 4.7V or 2.1V of constant signal voltage can be produced depending on ECU internal circuit..

Wiper type is the mostly used signal sensing type by now.

In order to response to the driver’s will quickly, fuel injection is controlled depending on the acceleration speed and pedal value. If the pedal value is more than 50%, then oxygen sensor feedback control is stopped to control the engine with more torque.

In case of sensor failure, intake air sensor is substituted for TPS. Therefore, fast accel and decel can not be detected with sensor failure and hesitation can be occurred.


Carman scan for ems professor

1.3.2 The Methodology of TPS Signal Measurement

Carman scan Mode : Please perform following procedure on the screen, - Vehicle selectionSystem(ENG)TPS Part(F4 key)  Measuring

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Remark :

As it is possible to use A,B channels at the same time, it is better to measure TPS and intake air flow simultaneously.

Sensor repair info view

About Sensor

Data analysis

Normal value


Carman scan for ems professor

Malfunction of TPS (1/2)

Cause of trouble

Trouble

1. Malfunction of throttle position sensor or wiring circuit failure

(Signal, Ground and Reference line)

2. Check ground line and connecting part. If there is something wrong, connect it

correctly. If it is occurred again after repairing, ECU should be changed with

latest version. (Many HMC vehicles have this problem)

3. Remove cause of noise

3.1 Shield sensor signal line.

3.2 Check whether spark plug is original part or not(Resistance range:2.0-4.5K)

1. The signal is always high or low.

2. The signal is intermittently missed(Micro cut-off occurrence).

3. The noise signal detection.

4. Even if idle state, ECU does not identify it.

Engine state

1. The vehicle hesitation is occurred with acceleration.

2. Idle TPS adaptation value is less than TPS absolute value at normal idle and

ECU doesn’t idle state even if real idle.Engine vibration is occurred with

this phenomenon.

3. Emission is increased.

4. The vehicle hesitation and vibration are occurred with acceleration.

Normal signal

1.3.3 TPS Trouble type and Analysis (1/2)

As can as possible, TPS signal should be compared with MAF sensor signal. And check whether TPS & MAF signal are increased at the same time when acceleration.


Carman scan for ems professor

Malfunction of TPS (2/2)

Signal wave when trouble detection

1.3.3 TPS Trouble type and Analysis (2/2)

1. Always constant signal

3. The noise signal detection

2. Intermittently signal missing (Micro cut-off occurrence)


Carman scan for ems professor

1.Field example of TPS malfunction : Signal missing by micro cut off

Cause of trouble

Trouble

TPS signal is cut off.

Accent 1.3L SOHC vehicle not only doesn’t identify idle state but also vibration

and stall are occurred. The hesitation is occurred with acceleration and scanner

doesn’t recognize idle state even if vehicle is real idle.

Related vehicle

This phenomenon is occurred in HMC vehicle which TPS ground line is connected with ECU outside ( Accent 1.3/1.5L DOHC etc )

Signal view

1.3.4 TPS Field Service Example (1/2)

TPS signal is sometimes “0” with normal MAF sensor signal.


Carman scan for ems professor

2. Field example of TPS malfunction : Signal noise occurrence.

Cause of trouble

Trouble

As connecting TCU, TPS signal noise is so much detected. ECU identify noise as fast acceleration, so it result in over fuel enrichment.

The emission is increased so much in idle state with Coupe 2.0L vehicle.

O2 sensor is normal feedback control but it is shifted to rich side.

Related vehicle

Vehicles which use same TPS wiring from TCU and ECU

Signal view

1.3.4 TPS Field Service Example (2/2)

TPS signal noise is so much detected “0” with normal MAF sensor signal.

Signal view


Carman scan for ems professor

About Sensor

Sensor type

Algorithm

1.4 Intake Air Flow Sensor Signal Analysis

1.4.1 Introduction of Intake Air Flow Sensor and Algorithm

This is the sensor to see how much air flow is coming into the cylinder. It is very important to calculate injection time. If the line is broken, then there are occasions when output voltage is over 4.7V depending on internal circuit like TPS.

Mostly used sensors by now are the MAP sensor ( Intake manifold pressure check ), MAF (Mass Air Flow :the resistance is changed when heated tip is cooled by inducted air )and Karman Vortex (This sensor monitors vortices generated as the intake air flows past vortex generators. Air flow is calculated by the frequency of ultrasonic waves that are changed depending on the amount of vortices. )

The fuel quantity is decided by the air flow and the injector opening time decides fuel quantity. The calculated fuel amount is compensated more precisely by oxygen sensor feedback compensation. In case of air flow sensor error, the substitute value is calculated by engine speed and TPS.


Carman scan for ems professor

Sensor repair info view

1.4.2 The Methodology of Air Flow Sensor Signal Measurement

Carman scan Mode : Please perform following procedure on the screen, - Vehicle selectionSystem(ENG)MAP Part(F4 key)  Measuring

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Remark :

As it is possible to measure A,B channels, it is better to measure intake air flow and TPS simultaneously.

Normal value

About sensor

Data analysis


Carman scan for ems professor

Malfunction of Air flow sensor

Cause of trouble

Trouble

1. Malfunction of air flow sensor or wiring circuit failure

(Signal, Ground and Reference line)

2. Check ground line and connecting part.If there is something wrong,connect it.

1. The signal is always high or low.

2. The signal is intermittently constant.

Engine state

1. Engine is hard to start. Even if it is started, vehicle hesitation is occurred

when acceleration

2. Intermittently vehicle hesitation or engine stall is taken place.

Normal signal

Signal wave when trouble detection

1.4.3 Air Flow Sensor Trouble type and Analysis

As can as possible, MAF signal should be compared with TPS signal. And check whether MAF and TPS signal are increased at the same time when acceleration.

As can as possible, MAF signal should be compared with TPS signal. And check whether MAF and TPS signal are increased at the same time when acceleration.


Carman scan for ems professor

Field example of Air flow sensor malfunction

:Abnormally high signal (Sensor is normal but signal is high)

Cause of trouble

Trouble

High MAP signal was detected because internal EGR was increased by exhaust pipe

blocking. Due to that, ECU identify big air flow and exhaust pressure make high.

It led to over fuel enrichment and poor acceleration due to lack of power.

Accent 2000MY vehicle is hard to start. Even if it is started, power is lack

with acceleration and exhaust gas is black color.

MAP signal is very high in idle state but scanner identify normal idle state.

Related vehicle

In case of MAP equipped vehicles,if exhaust pipe is blocked,this phenomenon is

always occurred. MAP signal is increased proportion to exhaust pipe blocking status.

Signal view

1.4.4 Air Flow Sensor Field Service Example

Signal(1.9volt) is slightly higher than signal of no load racing(0.8 - 1.5volt)


Carman scan for ems professor

About Sensor

Sensor type

Algorithm

1.5 Oxygen sensor signal analysis

1.5.1 Introduction of oxygen sensor and priciple

This is the sensor to compensate the fuel injection to get the stoichiometric air fuel ratio (14.6). The different voltage is generated depending on fuel richness ( oxygen richness ). According to this voltage variation, fuel injection is added or subtracted so that always relevant fuel is injected.

Mostly used sensor now is the Zirconia ( It generate the voltage from 0V to 1V by oxygen richness ), Titania ( It generate different resistance by oxygen richness ) and UEGO sensor ( It is used for lean burn engine and it generate different current by oxygen richness ). Titania and Zirconia sensors are classified with and without heater.

Oxygen sensor produce below 0.5V with rich oxygen( lean fuel) and over 0.5V with lean oxygen (rich fuel). Using this, ECU inject more fuel when oxygen sensor voltage is below 0.5V and reduce fuel as soon as voltage is over 0.5V. By continuing this control, supplied fuel is getting close to stoichiometirc air fuel ratio. This is the feedback control. In case of sensor failure, fuel is supplied by basic calculation.


Carman scan for ems professor

Sensor repair info view

1.5.2 The Methodology of O2 Sensor Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Vehicle selectionSystem(ENG)O2 sensor Part(F4 key)  Measuring

Remark : As it is possible to measure A,B channels, it is better to measure TPS too.

About

Data analysis

Normal value


Carman scan for ems professor

Malfunction of O2 sensor

Cause of trouble

Trouble

1. Malfunction of O2 sensor or wiring circuit failure

(Signal, Ground and Reference line)

2. Check ground line and connecting part.If there is something wrong,connect it.

3. A/F ratio distribution is unstable with individual cylinder

(Fuel gas is induced from outside)

4. O2 sensor tip is poisoned or exhaust gas temperature is too low.

1. The signal is always high or low.

2. The signal is intermittently constant

3. The switching is too fast.

4. The switching is too slow.

Engine state

1,2 If acceleration pedal is worked before engine warm-up before, engine stall is

occurred or power is lack. And also vehicle hesitation is taken place when

fast acceleration.

3. Engine vibration is severe. In case of knock sensor equipped, power is lack

and fuel economy make bad due to knock detection.

4. Engine stall is Sometimes occurred or exhaust gas is black with fast accel.

Normal signal

Signal wave when trouble detection

1.5.3 O2 Sensor Trouble type and Analysis

As can as possible, O2 sensor signal should be compared with TPS signal. And check whether O2 sensor signal is switched or not when acceleration.

If signal is switched, O2 sensor is normal.

1. Always constant

2. Slow szwithing

3. Fast switching


Carman scan for ems professor

1. Field example of O2 sensor malfunction : Too fast signal switching

Cause of trouble

Trouble

Vibration and knocking is decreased after repairing hydro tappet but it is still remained. It is cleared as using synthetic oil.

Elantra 1.6 vehicle vibration is severe in idle state and heavy knocking is detected.

O2 sensor signal is rapidly switched(Repeat high and low).

Related vehicle

Most vehicles are related, especially it is so much taken place when low quality is used during long time.

(In case of solid tappet equipped engine,if tappet is not adjusted,it is occurred)

Signal view

1.5.4 O2 Sensor Field Service Example (1/2)

In case of too fast signal switching, it is due to abnormal tappet opening and canister closing etc.


Carman scan for ems professor

2. Field example of O2 sensor malfunction : Too slow signal response

Cause of trouble

Trouble

Due to insufficient O2 sensor light off, signal is low and ECU start feedback control at this time. ECU identify that fuel is lean with low signal and it result in over fuel enrichment.

Accent 2000 MY vehicle hesitation or stall is taken place with acceleration after idling.

At this time exhaust gas is black color and acceleration is poor.

Related vehicle

This phenomenon is frequently occurred with optical crank angle sensor (MELCO 52 pin ECU).

Elantra, New sonata(1.8, 2.0L SOHC) etc.

Signal view

1.5.4 O2 Sensor Field Service Example (2/2)

Signal is stayed around 0.4 volt when problem occurrence. If acceleration pedal is continuously worked, signal is bigger and bigger as below picture by exhaust temperature.

< Counteraction >

O2 sensor is exchanged with heated type.Signal and ground line make connection same as before. And heater line is connected with after main relay and always operated with engine start. After this working, spark plug should be changed with new one and drive with high speed(2hours) to remove carbon in combustion chamber.


Carman scan for ems professor

About Injector

Injector type

Algorithm

1.6 Injector active signal analysis

1.6.1 Introduction of Injector and principle

The fuel quantity is decided by the air flow and the injector opening time decides fuel quantity. The injector open by electromagnetic power and close by spring force. Since the electromagnetic power is depending on battery power, injector opening time is compensated by battery power.

The principles of opening ( open by electromagnetic power and close by spring force )are mostly same. But it is classified into orifice and pintle type by injection hole.

If the signal of crank angle sensor has the noise or broken signal, ECU stop the fuel injection until it get normal signal of crank angle sensor.

Therefore, engine can be unstable or stall.


Carman scan for ems professor

Sensor repair info view

1.6.2 The Methodology of Injector Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Scope meter  Engine  Actuator Injection Measuring

.

Normal value

About sensor

Data analysis


Carman scan for ems professor

Malfunction of Injector

Cause of trouble

Trouble

1. Wiring circuit failure (Power supply and Ground line)

2. Crank angle sensor noise detection

3. Carbon accumulation in combustion chamber or

fuel filter problem by other materials.

1. Injector is not opened.

2. Intermittently injector is not opened.

3. The clogging of injector.

Engine state

1. Vehicle vibration is severe after start.

2. Vibration or engine stall is intermittently occurred.

3. Vehicle vibration is severe and engine sound is loud.

Normal signal

Signal wave when trouble detection

1.6.3 Injector Trouble type and Analysis

Peak voltage and injector opening time is equal to individual cylinder without acceleration pedal.

In case of clogging of injector or taking out from engine, it can be checked by O2 sensor signal.

1. Always constant

2. Injector is not opened

3. Clogging of injector


Carman scan for ems professor

1. Field example of Injector malfunction : Clogging of injector tip

Cause of trouble

Trouble

Valve overlap is too big (55 deg). Carbon make clogging of injector.

Coupe 2.0L DOHC (Camshaft modified vehicle): Checked O2 sensor signal due to

severe engine vibration. O2 sensor signal switching is too fast.

Related vehicle

Most vehicle which has big valve overlap and use injector exception pintle type make this phenomenon.

Signal view

1.6.4 Injector Field Service Example (1/2)

Abnormal O2 sensor signal. It is due to abnormal A/F distribution with individual cylinder. Fuel is not supplied in a certain cylinder.

Even if injector is clogged, injector signal is normal on scanner.


Carman scan for ems professor

2.Field example of Injector malfunction:Sometimes not opened injector

Cause of trouble

Trouble

Abnormal crank angle signal is detected due to noise detection, so ECU cut off

fuel injection . At this time problem is taken place.

New sonata (MAP sensor) vehicle vibration is intermittently occurred and

engine stall. This is not taken place regularly.

Related vehicle

This phenomenon is occurred with optical or magnetic type crank angle sensor.

Signal view

1.6.4 Injector Field Service Example (2/2)

O2 sensor signal is mainly below 0.5 volt(lean shift) but sometimes show above 0.5 volt(rich shift).

We don’t know whether ECU identify noise detected crank angle signal. If injector is not opened, you can think that ECU identify noise signal.

< Counteraction > Shield crank angle sensor signal line to prevent noise.


Carman scan for ems professor

1.7 Ignition System Signal Analysis

Refer to

“Chapter 2 Application of Ignition Secondary Wave”


Carman scan for ems professor

About ISC valve

ISC valve type

Algorithm

ISC valve

ISC valve

Control line

Control line

Control line

Control line

Control line

GND Duty control

Control line

Engine speed

Target speed

Engine speed

ISC valve opening

1.8 ISC valve control signal analysis

1.8.1 Introduction of ISC valve and principle

ISC valve is the valve that bypass the air to keep constant engine speed when throttle valve is closed. ECU control only the opening of the valve and air is supplied by the under pressure in the surge tank..

Three mostly used type are DC type controlled by DC motor, Duty type controlled by duty and Step type controlled by the electromagnet

Duty type (2 coil)

Step motor type

The ECU compare the engine speed with target speed and open or close the valve when engine speed is lower or higher than target. This compensation is composed of proportional, integral and differential term- so called PID control..


Carman scan for ems professor

1.8.2 The Methodology of ISC Valve Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Scope meter  Engine  Actuator  ISC Measuring

Sensor repair info view

IAC valve

IAC valve

Data analysis

Normal value

About sensor


Carman scan for ems professor

Malfunction of ISC valve

Cause of trouble

Trouble

1. Wiring circuit failure (Power supply and Ground line) or

Malfunction of TR in ECU

2. Wiring is normal but valve is not operated by carbon or step loss etc.

(Step loss : The difference between ECU control and actual opening duty)

3. Carbon accumulation in air flow path

1. ISC is not opened.

2. Intermittently ISC is not opened.

3. The closing stuck of ISC valve.

Engine state

1, Even if engine start is possible, it is stalled soon or severe vibration

is occurred. (In case of BOSCH ISC, engine speed is stayed around 1500rpm)

2. If it is occurred with little opening,engine vibration or stall is taken place

If it is occurred with big opening, engine is stayed with high speed.

3. As soon as engine is started, it is stalled.

Normal signal

Signal wave when trouble detection

1.8.3 ISC Valve Trouble type and Analysis

ISC valve signal have difference according to which type is used.

(Duty type / DC motor type / Step type)

1. Always constant

2. ISC valve stuck

3.ISC valve close stuck

Although ISC valve is stuck with closed position ,signal is normal. So, it can be checked by actuator operation. “ Refer to chapter 5”


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1. Field example of ISC malfunction : Clogging of ISC valve pintle

2. Field example of ISC malfunction : ISC valve step loss

Cause of trouble

Trouble

Trouble

Cause of trouble

Leaking oil from turbo is mixed with carbon. It led to block ISC valve pintle.

Trajet XG 2000MY stall is frequently occurred and engine start is hard.

Trajet XG 2000MY vehicle: If engine stall is occurred,

it is frequently taken place.

Step between ECU control and actual opening have big difference. At this time,

ISC valve adaptation is abnormal and opening duty is not controlled properly.

So, this phenomenon is taken place.

Related vehicle

Related vehicle

This is occurred with step motor malfunction or aging vehicle(Above 50,000 km/h) without step motor equipped.

This is often occurred with duty type ISC valve equipped vehicles, especially 1 coil type is more frequent.

Signal view

Signal view

1.8.4 ISC Valve Field Service Example

There is no problem in ISC signal, only ISC pintle is not operated.

Carbon in pintle should be cleared.

There is no problem in ISC signal, only ISC pintle is not operated. ISC valve should be cleaned after disassembling. And reset ISC adaptation value and stay idle state more than 10 minute.

This step loss is not cleared completely. Although it is repaired or exchanged with new one, it may occur later.


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About Sensor

Sensor Type

Algorithm

1.9 Temperature sensor signal analysis

1.9.1 Introduction of temperature sensor signal and principle

Coolant sensor is a sensor for detecting of how much engine is heated up and necessary to control injection/ignition/ISC valve depending on engine temperature. Because engine load is surely different depending on engine temperature.

Intake air temperature sensor is used to calculate exact intake air flow and necessary for MAP sensor type. But it is often not to use it with MAF(Mass air flow )type.

Some of MAP sensor include intake air temperature sensor inside and it is called T-MAP sensor.

Mostly used type is a thermistor type that increase the resistance with high temperature and decrease the resistance with low temperature.

.

Intake air temp. sensor

T_MAP sensor

Coolant temp. sensor

Intake air temperature sensor is a sensor for calculating intake air quantity more exactly. The coolant temp. sensor is to set different target of fuel(Air Fuel ratio)/target speed/ spark time in accordance with coolant temperature to compensate different engine load

Target lambda area without feedback control depending on coolant temp

Target ignition area depending on coolant temp. - idle status

AF range

Spark range

Coolant Temp.


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1.9.2 The Methodology of Temperature Sensor Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Scope meter  Engine  Sensor  WTS Measuring

Sensor repair info view

Coolant sensor

Coolant sensor

Coolant sensor

Data analysis

Normal value

About sensor


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Malfunction of Temperature sensor

Cause of trouble

Trouble

1. Wiring circuit failure (Signal or Ground line open or shorted)

2. ECU internal circuit malfunction or temperature sensor position is not proper.

1. Signal line open circuit (Temperature is below -30 deg.C )

2. Signal line short to ground (Temperature is above 127 deg.C )

3. Temperature signal change is too fast.

Engine state

1. Poor acceleration or exhaust gas is black due to over fuel enrichment.

It is returned normal after 10 minute.

2. Intermittently idle rpm is oscillating (800 - 1000rpm).

Normal signal

Signal wave when trouble detection

1.9.3 Temperature Sensor Trouble type and Analysis

Temperature sensor signal have difference according to which type is used.

(Duty type / DC motor type / Step type)

1. Always constant

2. Temp. signal rapidly change


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Field example of Temp.sensor malfunction : Fast coolant signal change

Cause of trouble

Trouble

Engine speed is oscillated by coolant temperature change due to ECU internal circuit malfunction. Idle engine speed is set with ECU data by coolant temperature in ECU.

Accent 2000MY vehicle : Engine speed is oscillating from 800 to 1000rpm with

idle state.

Related vehicle

Siemens ECU(52 pin) has sometimes problem but other ECU may have this phenomenon.

Signal view

1.9.4 Temperature Sensor Field Service Example

Engine speed is changed with coolant temperature oscillating. If actual coolant temperature is constant. The problem is still remained after TCO sensor change(3ea) but it is cleared after ECU change.

If you want to measure temperature, please refer to “Chapter 4 Multi meter utilization”


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About Sensor

Sensor type

Algorithm

1.10 Knock sensor signal analysis

1.10.1 Introduction of knock sensor and algorithm

The knock sensor employ the piezoelectric element or silicon that produce the signal(voltage) when it gets pressure. If there is knocking in the engine, then vibration is transformed to pressure vibration and it produces voltage. According to this voltage, knocking is detected.

It is difficult to distinguish the knock sensor type by means of sensor shape. But the element to detect vibration may be different.

Knock sensor

The frequency of knocking signal is too fast(about 6 - 18Khz) to analyze it by ECU.

Therefore, this signal is sampled by hardware and knocking is detected.

But the frequency of bad engine vibration can be overlapped with frequency of knocking. So, too much knocking can be detected by engine vibration.


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1.10.2 The Methodology of Knock Sensor Signal Measurement

Carman scan Mode : Please perform following procedure on the screen, - Scope meter  Engine  Sensor  Knock Measuring

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Sensor repair info view

Data analysis

Normal value

About sensor


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Malfunction of Knock sensor

Cause of trouble

Trouble

1. Wiring circuit failure (Signal or Ground line open or shorted)

or knock sensor malfunction

2. A/F is different with individual cylinder.(Refer to 2.6injector trouble)

3. ECU internal circuit malfunction (Should be changed ECU)

1. Knocking signal is always constant (Signal line open or shorted)

2. Heavy knocking detection

3. Knock signal is normal but knock is not detected

(Communication malfunction of knock signal in ECU)

Engine state

1.If ECU detect knock sensor error, ignition is retarded(6-12deg).

It result in lack of power and bad fuel economy.

If ECU don’t detect error,ignition is not retarded even if knocking is occurred.

2 Too much ignition retard(6-12deg) make lack of power and bad fuel economy

3.Same as NO.1 description.

Signal wave when trouble detection

Normal signal

1.10.3 Knock Sensor Trouble type and Analysis

Knock sensor signal have difference according to which type is used.

(Duty type / DC motor type / Step type

1. Always constant

2. Heavy knocking detection

Heavy knocking

Abnormal : constant signal

Normal signal

Normal signal


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Field example of Knock sensor malfunction : Heavy knocking detection

Cause of trouble

Trouble

Cylinder #1 intake valve is not opened properly due to malfunction of #1 rocker arm operation. It result in engine vibration and ignition retard by heavy knocking detection. So, ignition retard make lack of power and bad fuel economy.

Trajet XG 2000MY vehicle: The power is lack with driving and fuel economy is bad.

Related vehicle

In case of knock sensor equipped vehicles, if engine state is unstable, it guess knocking detection.

Signal view

1.10.4 Knock Sensor Field Service Example

This signal can be also checked with O2 sensor signal.

Knock signal with problem detection

O2 sensor signal with problem detection

Heavy knocking

Normal signal

Knock I.C exist in ECU. If it has malfunction, knocking detection is impossible. But ECU can detect whether it properly works or not.


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About Sensor

Sensor Type

Rotor rotate with the cable connected to driving shaft

Algorithm

VS sensor

A hole for cable connection

VS sensor(lead switch type)

1.11 Vehicle speed sensor signal analysis

1.11.1 Introduction of vehicle speed sensor and principle

Vehicle speed sensor is a sensor that check wheel speed per second to calculate vehicle speed.

It measures speed of body of rotation that directly connected with driving shaft.

Mostly used vehicle speed sensor are lead type (switch on and off at every revolution )/ magnetic type and hall type.

Magnetic and hall type is same principle as crank angle sensor.

Vehicle speed is calculated by calculating how many voltage over the threshold(normally 1.0 - 2.5V) are generated at one second. If the noise signal is over the threshold, then it is recognized as vehicle speed.

Vehicle speed signal is required for AT car to decide gear shifting level and for MT car to reduce the shock during fast acceleration by adjusting spark time and fuel depending on vehicle speed and gear level.

ECU calculates the gear level using engine speed and vehicle speed.


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Vehicle speed

Vehicle speed

1.11.2 The Methodology of Vehicle Speed Sensor Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Scope meter  Engine  Sensor  Vehicle Speed Measuring

Sensor repair info view

Vehicle speed

Data analysis

Normal value

About sensor


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Malfunction of Vehicle speed sensor

Cause of trouble

Trouble

1. Wiring circuit failure (Signal or Ground line open or shorted)

or vehicle sensor malfunction

2. Too much signal noise detection in vehicle speed sensor

1. Any vehicle speed sensor signal is not detected with driving.

2. Vehicle speed is much higher than actual speed. (Too much signal noise)

3. Even though vehicle stop, ECU identify vehicle speed.

Engine state

1. Engine RPM is slightly high in idle state and it is oscillating.

2. In case of A/T vehicle, shift point is high gear position and it is shifted with 2 or 3 gear when take off.

Normal signal

Signal wave when trouble detection

1.11.3 Vehicle Speed Sensor Trouble type and Analysis

Vehicle speed signal should be detected in driving. It should be always constant at vehicle stop.

1. always constant

2. Noise detection in VS signal


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Field example of VS sensor malfunction : Signal noise detection

Cause of trouble

Trouble

Too much noise is detected in VS signal. ECU identify driving with high speed.

Grandure XG V6 2.0L DOHC vehicle: Vehicle take off with 2 or 3 gear shifting.

Acceleration is impossible and VS is displayed with 40 - 70 Km/H on scanner

even if vehicle stop.

Related vehicle

All vehicles (Especially in case that ECU receive VS signal from TCU)

Signal view

1.11.4 Vehicle Speed Sensor Field Service Example

VS signal with problem detection

VS signal is not related to shape.

Only check how many detect signal above 1.0 volt per 1sec.


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About EGR

EGR type

Algorithm

1.12 EGR valve control signal analysis

1.12.1 Introduction of EGR valve and principle

This is a valve to add exhaust gas into the cylinder and so the combustion temperature is reduced.

Reduced combustion temperature results reducing of nitrous-oxide emission.

Exhaust gas is supplied through this valve by under-pressure of surge tank.

Mostly used one is mechanical type that the valve is opened by under-pressure of surge tank as soon as solenoid valve is opened. And the solenoid valve is opened by ON/OFF system or duty system. In case of EEGR(Electric EGR) type, the EGR valve is opened by electromagnetic power..

Electric EGR valve

Mechanical EGR valve

EGR valve is opened within the range(2 - 7%) that is not to give big influence on engine operation. Opening value is controlled not to have big engine vibration. Therefore, in case of ON/OFF type, ON signal is activated in the area (engine speed & intake air flow )where no engine problem is found. With the EGR gas, ignition angle should be retarded about 4 - 8 degree

If the EGR gas is provided into the cylinder, combustion temperature is reduced and it is effective on reducing of nitrous-oxide emission.


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1.12.2 The Methodology of EGR Valve Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Scope meter  Engine  Actuator  EGR valve  Measuring

Sensor repair info view

EGR sensor / EGR valve

EGR sensor / EGR valve

Data analysis

Normal value

About sensor


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Malfunction of EGR valve

Cause of trouble

Trouble

1. Wiring circuit failure (Power supply or Ground line open or shorted)

or EGR solenoid valve malfunction

2. EGR valve is stuck for a while or friction increase by over heating.

1. Malfunction of valve operation

2. EGR valve closed stuck

3. EGR valve opened stuck

Engine state

1. Severe engine vibration is occurred(Open stuck) or

lean fuel control(MAP sensor type).

2. lean fuel control(MAP sensor type), fuel adaptation is increased to positive

direction. Knocking is often taken place.

3 Severe engine vibration

(Engine is hard to start or severe engine vibration after start)

Normal signal

Signal wave when trouble detection

1.12.3 EGR Valve Operation Trouble type and Analysis

EGR valve operation can be checked only if it is operated. So, it should be checked with working acceleration pedal.

1. Always constant

EGR valve stuck is not checked with signal,indirectly it can be checked with O2 sensor signal. “Refer to O2 sensor chapter”


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Field example of EGR valve malfunction : EGR valve closed stuck

Cause of trouble

Trouble

EGR gas is not supplied in combustion chamber due to EGR valve closing stuck. At this time, ECU reduce fuel injection as much as EGR duty. So, injection is not sufficient and fuel adaptation is increased. And also knocking is occurred because ECU apply EGR activated ignition.

Grandure XG V6 3.0L DOHC vehicle : Knocking is often taken place and intermittently

fuel control is rich because fuel adaptation is increased to positive direction.

Related vehicle

This is occurred at EGR valve equipped vehicles with MAP sensor. MAF(Mass Air Flow:Hot Film Type)is also happened if ECU separately control EGR activated ignition.

Signal view

1.12.4 EGR Valve Field Service Example

O2 sensor signal with problem detection

EGR valve stuck is not checked with signal,indirectly it can be checked with O2 sensor signal.


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About valve

Part type

Algorithm

1.13 Purge valve control signal analysis

1.13.1 Introduction of purge valve control and principle

Fuel vapor gas from fuel tank is not emitted to the air but stored in the canister to follow the emission regulation. And then this fuel vapor gas is supplied to the engine via purge valve during engine running.

Mostly used one is solenoid valve type that uses under-pressure of surge tank while valve is open. This is also divided into ON/OFF and duty type..

Purge solenoid valve

Canister

Purge valve is opened in the limit area no to give big influence on engine operation. Opening amount is controlled no to have rpm drop by too much rich fuel caused by purge gas. Therefore, in case of ON/OFF type, ON signal is controlled to activate in the area ( engine speed, intake air flow )of no engine problem.

If purge gas is supplied into the cylinder, mixture is getting richer. But as it is compensated by oxygen sensor, total fuel amount is same


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Sensor repair info view

1.13.2 The Methodology of Purge Valve Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Scope meter  Engine  Actuator  Purge valve  Measuring

Canister purge solenoid

Canister purge solenoid valve

Data analysis

Normal value

About sensor


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Malfunction of Purge valve

Cause of trouble

Trouble

1. Wiring circuit failure (Power supply or Ground line open or shorted)

or Purge solenoid valve malfunction

2. Purge valve is stuck for a while or friction increase by over heating.

1. Malfunction of valve operation

2. Purge valve closed stuck

3. Purge valve opened stuck

Engine state

1. Severe engine vibration is occurred when hot start(Open stuck) or

over fuel enrichment control.

2. The smell of fuel gas is detected from vehicle.

3. Severe engine vibration is occurred when hot start(Open stuck) or

over fuel enrichment control.

Normal signal

Signal wave when trouble detection

1.13.3 Purge Valve Operation Trouble type and Analysis

Purge valve operation can be only checked with driving. It should be always constant with vehicle stop.

1. Always constant

Purge valve stuck is not checked with signal,indirectly it can be checked with O2 sensor signal. “Refer to O2 sensor chapter”


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Field example of Purge valve malfunction : Purge valve opened stuck

Cause of trouble

Trouble

Purge valve is stuck at closed position with hot condition. At this time, over fuel gas is supplied into engine when vehicle start and it lead to make hard vehicle start.Engine vibration is still remained until fuel gas is completely exhausted.

Coupe vehicle : Engine is hard to start when hot summer season.

And fuel control is so rich with engine vibration after start.

Related vehicle

This is frequently taken place with Siemens purge valve equipped vehicle. With BOSCH valve, it is sometimes occurred.

Signal view

1.13.4 Purge Valve Field Service Example

O2 sensor signal with problem occurrence

Purge valve stuck is not checked with signal,indirectly it can be checked with O2 sensor signal when fuel control is too rich.


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About sensor

Sensor type

Algorithm

1.14 Oxygen sensor heater control signal analysis

1.14.1 Introduction of oxygen sensor control and principle

Oxygen sensor heater is a heater to heat up the tip of oxygen sensor. Since oxygen sensor activate when the sensor temperature is over 370degC, heater is needed to prevent delay of signal at low exhaust gas temperature.

There are oxygen sensor without heater too. Oxygen sensor without heater is used to reduce the cost.

In order to prevent sensor over-heating, heater control is stopped at high exhaust gas temperature area. In case of engine start, sensor might be cracked by heating due to water on the sensor. Therefore, heating is start after water is evaporated


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1.14.2 The Methodology of O2 Sensor Heater Signal Measurement

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Scope meter  Engine  Sensor  O2 sensor Measuring

Sensor repair info view

Normal value

About Sensor

Data analysis


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Malfunction of O2 sensor heater

Cause of trouble

Trouble

1. O2 sensor heater damage

2. Wiring circuit failure (Power supply or Ground line open or shorted)

1. Malfunction of valve operation

(Power supply line is no problem but O2 sensor is not heated)

2. O2 sensor is not activated (Always OFF)

Engine state

1,2 O2 sensor signal switching is too slow (Too slow light off)

Intermittently exhaust gas is black and poor acceleration is detected and

engine stall is occurred when fast acceleration. Fuel economy is bad.

Normal signal

Signal wave when trouble detection

1.14.3 O2 Sensor Heater Operation Trouble type and Analysis

O2 sensor heater should be always “ON” if after start time is elapsed 40 sec

(In case of duty type, it is “ON” above 95%)

1. Always constant

If O2 sensor heater signal is “OFF” when idle, error is detected.


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Field example of O2 sensor heater malfunction : Crack of tip

Cause of trouble

Trouble

O2 sensor heater should be operated after removing humidity around tip.

But as soon as engine is started, O2 sensor is heated at the same time.

It result in crack of O2 sensor tip.

HMC vehicles for US market : O2 sensor malfunction is many taken place in early

winter season

Related vehicle

Vehicle which is manufactured before 1995 year

(BOSCH O2 sensor:Frequently occurrence, Woojin O2 sensor:Sometimes occurrence)

Signal view

1.14.4 O2 Sensor Heater Field Service Example

O2 sensor signal with problem occurrence

O2 sensor signal is not switched (Always constant).


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2. Application of Ignition Secondary Wave

2.1 General explanation & principle of

Ignition secondary wave

2.2 Measuring method of Ignition secondary wave

2.3 Analysis of Ignition secondary wave

2.4 Field Examples


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2.1 General explanation & principle of Ignition secondary wave

The calculated time for ignition system by ECU are spark time and dwell time.

The dwell time is to induct current to primary coil to get 60A and it is compensated by battery power.

Dwell time is the power charging duration of primary coil. The longer dwell time is the higher current. That means, if this power charging duration of primary coil is long, then current is high and ignition energy (E = VA) is high so that combustion in the cylinder is

stable with strong spark energy.

But the problem is that electric energy is increase as current is increase. If it is too big then there will be a problem with endurance of ignition coil. So, with good endurance of ignition coil, we can increase dwell time, which gives high current.

But, as it needs more money to increase endurance with current ECU that have power TR inside, current is controlled to a certain value (generally 6A) as fast as possible.

Therefore eclectic current is changed very fast by dwell time and there is big difference of electric current by small dwell time change.

Then what is a countermeasure of carmaker?


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The countermeasure is to prevent over current, but there is no countermeasure for low current.

Because over current can give damage on ignition coil or power TR while low current does not give big problem with small secondary voltage and small ignition spark.

The reason why it is not a big problem is as following.

The secondary voltage signal is almost similar at each engine operating conditions, but generation and destruction of instant high voltage is very various. Especially, it is depending on combustion chamber shape and engine operating conditions (temperature, airflow and mixture condition) and even with same conditions, it can not be regular. Therefore, in my opinion, to investigate engine condition with secondary voltage signal can give only few information such as problem of spark plug and coil wiring or decreasing of compression rate. If you want to understand the combustion condition exactly, you have to look at cylinder pressure.

Some of electric control unit maker and carmaker’s research center use the sensor that equipped inside the spark plug to see cylinder pressure variation.

Back to main subject, in fact, to say no problem with small ignition energy is dangerous. To say exact meaning, when engine is in idle at cold state (Coolant below -10C), energy of approximately 1J is required and energy of approximately 1 – 3mJ is required for warm-up engine with oxygen sensor feedback control. And more energy is required during acceleration or for rich mixture or for lean mixture. But normally required energy for warm-up engine is one-hundredths of cold engine.

As carmaker make there ignition system to get enough energy at cold state, if there is no trouble with ignition system then there will be no big problem with low current at warm-up engine. Then what is the effect when we limit over current on ignition system?


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If we limit the current then we can see that voltage increase by a step. This does not give any influence on engine (combustion condition), but ignition system has to consume more energy by itself. And this current size is depending on battery voltage.

So, according to battery voltage, ECU gives different dwell time. As a reference, ECU has several power supply lines with different purposes and the line for battery voltage recognition is used to compensate battery voltage.

What if battery voltage is changed due to high resistance or noise in the battery voltage line, which is connected to ECU?

Then ignition sparks for each cylinder is irregular due to frequent changing

of ignition enrage by irregular dwell time.

This phenomenon happens more in hot summer with complex power supply wiring to ECU.

Then what will be influence by this phenomenon? First, engine combustion is unstable

due to unstable current flow. And this leads engine vibration. In case of knock sensor, engine

vibration generates knock sensor signal and ECU detect this signal as knocking and retard spark time.

< Reference>

ECU analyzes knock sensor signal frequency to define real knocking frequency (generally 8-13KHz) from the engine. Yet, engine vibration due to different ignition power between each cylinder can be detected as knocking.

How can the technician find out this condition that has very short difference of dwell time? It is difficult. But it can be suspected that dwell time is unstable when battery voltage from the power line that recognized by ECU is irregular.

If engine vibration is severe with that condition, connect power line for voltage recognition to the ECU directly with one line.


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2.2 Measurement of Ignition Secondary Wave

How to connect Carman scan : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.

Carman scan Mode : Please perform following procedure on the screen, - Vehicle Scope  Automatic scope  Ignition  Measuring

Connection of Pick-up cable

Connection of Ground wire

Normal value

Analysis of data


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2.3 Analysis of Ignition Secondary Wave

A. Measurement of Ignition primary wave.

Ignition secondary wave shows discharging status according to the status of the cylinder.

As it has a complicated relation with status of components and wires which control electrical energy at first coil, status of second coil which is induced by high voltage and status of mixed gas in the cylinders representing how much thermal electrons discharge while being discharged finally, To confirm whether status of supplying electrical energy to ignition system is good or not, it is desirable to check the current from first coil at each cylinder.

To generate enough ignition energy at secondary voltage, there must be enough current at first coil. Although this current is different according to the sorts of the vehicle, generally 60.5A is considered as a standard.

The point keeping in mind is despite this current is weak, ignition secondary wave may not have any problem.

If air-fuel ratio in the normal temperature (over 20 °C) is closer to stoichiometric , Ignition by secondary voltage is possible with approximately 1/200~1/1000 energy of the ignition energy in the cold temperature (below -5°C).

In case that the current flows weak , but ignition secondary wave has no problem,

Ignition secondary wave must be confirmed whether it is normal state at rapid acceleration, cold temperature, both rich and lean of fuel condition.

Ignition energy at normal temperature and stoichiometric condition : 1~2mJ

Cold temperature and Rich fuel: approximately 1J


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Checkpoint for current and primary ignition wave.

  • 1)Distributor Less Ignition type

  • < Measuring part >

  • Measure flowing time and the current at checkpoint 1,2

  • <Checkpoint>

  • Resistance of wire, status of components (checking components 1: internal ECU or external TR)

2) Distributor Ignition type

<Measuring part>

Measure flowing time and the current at checkpoint 1,2

<Checkpoint>

Resistance of wire or a short, status of components (checking components 1: internal ECU or External TR, checking components 2: ignition coil)

Most important point is dwell time(depends on battery voltage). If battery voltage is 13.5V the dwell time is 3.0~3.5msec. Cylinder by cylinder deviation(over 20%) check is required to know the normal or not. If the deviation is more than 20%, it means coil, power TR or wire has a problem..

Also check the ECU recognized battery voltage is stable(within 3V). Because the dwell time can be some difference depends on battery voltage.


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B. Measurement of Ignition

Secondary wave

Ignition secondary wave means discharging to high voltage from electric energy at first coil. Especially ignition system in automobile, discharging time & discharging voltage level is affected more by status of the mixed gas in the cylinders and plug than electric energy from first coil.

When secondary high voltage (approximately 20000~30000V) is induced instantly and flows, the flow means discharging, time is discharging time, Voltage is discharging voltage.

When the secondary voltage generates, this energy separates carbon and hydrogen from constituent of fuel.

<Ignition secondary wave: classification of each wave>

While this constituent of fuel separates, electrons are generated. It’s called thermal-electron.

Discharging voltage combusted normally

from the cylinder is a voltage discharging through those thermal-electrons.

Since level and time of the discharging voltage are affected by the temperature and shape (vortex) in the cylinder, air-fuel ratio of the mixture, and compression ratio, it is hard to fix absolute value. So it must be analyzed through comparing each cylinder.


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Parts to confirm ignition secondary wave are as follows.

1) Distributor less type

<Measuring parts>

Measure flowing time and the current at checkpoint 1,2

<Checkpoint>

Resistance of wire, status of components

2) Distributor Ignition type

<Measuring part>

Measure voltage secondary wave at

checkpoint 1,2(plug wire at each cylinder)

<Checkpoint>

Resistance of wire or short, status of components (checking components 1,2)


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. Comparing each cylinder

(1) After a current flowed, if peak (voltage of surge) is low or discharging time is short

and high:

This means that electric energy through discharged thermal-electron isn’t discharging

well,while molecule separates from fuel.Electric energy trying to ignite isn’t for fuel

combustion , it’s kind of discharging phenomenon through plug ejja. So misfire occurs

in the cylinder.

  • A.Confirm the status of plug

  • (attached carbon, clearance)

  • When a peak voltage is generated,

  • some parts of voltages flow on the

  • attached carbon in the plug tip. So

  • it gets weak to separate molecule.

  • In case that discharging voltage

  • flows through carbon to plug.

  • B.Check plug wiring and status of coil

  • In case that connection to plug

  • and high voltage wire and coil status

  • aren’t good , peak voltage becomes weak.

  • Then electric energy to separate

  • fuel molecule becomes weak because

  • Thermal-electrons generated from fuel

  • are little so that resistance

  • discharges large state..

  • c.Check if the mixture ratio of fuel is too lean

  • In case that fuel is lean, even more electric energy is needed to generate thermal-

  • electrons separated from fuel molecule.thus peak voltage generated near

  • stoichiometric with normal fuel isn’t enough to generate thermal-electron so that

  • resistance dischargelarge state

  • d.Check if the compression ratio is too high

  • In case compression is high, far more electric energy is needed to generate

  • thermal-electrons separated from fuel molecules.

  • Thus peak voltage generated near normal compression ratio isn’t enough to generate

  • thermal-electron so that resistance discharges large state. It isn’t for normal case.

  • it’s for especially reorganized vehicle. Just do interpret that as theoretical aspect.

In 4 cylinder engine , If one cylinder has some troubles, the troubles are made in two cylinders at the same time. Therefore when measuring wave with Carman scan, choose “one of NO1.and NO3.” or “ one of NO2. and NO4.” then measure 2cylinders at the same time.


Carman scan for ems professor

(2)After a current flowed,if a peak(voltage of surge) is low and discharging time is long:

Although electric discharge is well,it causes power reduction because discharging

electric energy (spark) gets weak and long so that combustion timing of fuel gets long

and flame spread leading to combust between fuel particles gets weak

a. Check status of plug (clearance of tip is too small)

b. Check compression pressure of cylinder is low

c. Check the mixture ratio is too rich

<Reference>

More detail refers to chap 6.”6.3 uniform ignition energy to each cylinder.

In 4 cylinder engine , If one cylinder has some troubles, the troubles are made in two cylinders at the same time. Therefore when measuring wave with Carman scan, choose “one of NO1.and NO3.” or “ one of NO2. and NO4.” then measure 2cylinders at the same time.


Carman scan for ems professor

Ignition Energy Discharging Time

For ignition, high voltage must be generated and sparked on ignition plug tip in cylinder

But actually to combust fuel in cylinder, discharging must be done continuously for some

time.Because spark from combusted fuel in cylinder must transfer flame to other surrounding fuel. If intake air is little (idle, deceleration), air playing a role on transferring

flame and fuel mixture gets lack and compression ratio is low in cylinder so that

there is high possibility to occur misfire.

  • Actually in US regulation (OBD2: On Board Diagnostic2), if misfire rate is over regulation on exhaust gas, ECU recognizes as a malfunction

  • It is written that “if intake air is little, misfire exempts from regulation

  • So to speak, this means it admits air lack case is inevitable on air-fuel mixture transferring flame to the cylinder.

  • But if enough secondary voltage keeps for some time (about 1,5msec), these misfire decreases.

  • There is some product (CDI) making secondary voltage strong and discharging long time. The purpose of those products is on that.

  • Compression pressure in cylinder according to ignition timing.

Although the direct way to keep discharging time is to produce CDI, there is also indirect way to keep pressure in cylinder high. One of them is to retard ignition timing.


Carman scan for ems professor

1. Field example of Ignition secondary wave : In case heat value of plug is too high

Trouble

Cause of trouble

Coupe 2.0L DOHC vehicle which platinum plug is equipped has poor performance

when acceleration,black color of exhaust gas and engine start is hard in cold

ambient condition.

Combustion wasn’t well due to high heat-value Pt plug

Related Vehicle

All vehicle equipped with too high heat-value Spark plug

Signal View

2.4 Field Service Example of Ignition Secondary Wave (1/3)

Big difference at wave between appropriate plug and high heat-value plug. (Discharging time is short with cold heat-value plug)

< Reference >

Since waves are different according to vehicle/ engine/ temperature of temperature, there were no absolute standard. It should be compared when it is normal condition.

Pt plug equipped

Comparison pt plug with appropriate one


Carman scan for ems professor

2. Field example of Ignition secondary wave : In case too much noise is generated from

plug

Cause of trouble

Trouble

Effected on ECU by being used no resistor plug, at ignition excessive noise was generated.

New sonata (Map) Cranking isn’t well,After cranking engine disorder is severe.

Related Vehicle

All vehicles equipped with no resistor plug (except using SIEMENS 55 pin ECU)

Signal View

2.4 Field Service Example of Ignition Secondary Wave (2/3)

Big difference at wave between appropriate plug (resistance:3.5~4.5 kohm) and no resistor plug. (After discharging, finishing is well)

< Reference >

Since waves are different according to vehicle/ engine/ temperature of temperature, there were no absolute standard. It should be compared when it is normal condition.

No resistor plug

Comparison no resistor plug and appropriate one


Carman scan for ems professor

3. Field example of Ignition secondary wave : In case Compression ratio at cylinder is low

Cause of trouble

Trouble

Since too much carbon was attached on intake valve stem, no problem at cold condition, but engine gets warmer stem expands so that compression pressure gets lower because stem can’t be closed well.

Avante 1.5L DOHC Vehicle is a normal at cold engine condition, engine gets

warmer, engine disorder happens.

Related Vehicle

All vehicles used too much fuel annex to raise octane value, probability is high.

Signal view

2.4 Field Service Example of Ignition Secondary Wave (3/3)

One of two ignition secondary wave discharging time is long and discharging voltage is low.

< Reference >

Since waves are different according to vehicle/ engine/ temperature of temperature, there were no absolute standard. It should be compared when it is normal condition.

Pressure in cylinder is low


Carman scan for ems professor

3. Multi-meter Utilization

3.1 Repair by measuring current

3.2 Repair by measuring pressure

3.3 Repair by measuring temp.


Carman scan for ems professor

Measure

Compression pressure

Check compression leak at each cylinder

3.1 Repair by measuring current

3.1.1 Measuring of Large current ( 1 - 600 A )

How to connect Carman scan :

Can be used by B channel, connect cable for measuring large current to main line (battery ).

Carman scan mode : Please perform following procedure on the screen

-Vehicle scope Oscilloscope  Measure

Connection of Current cable

Explanation of current probe

Cranking current

Check status of battery charging


Carman scan for ems professor

Measure

3.1.2 Measuring of Small current ( 50mA - 100 A )

How to connect Carman scan :

Can be used by B channel, connect cable for small current to each component power supply line.

Carman scan mode : Please perform following procedure on the screen, -Vehicle scopemeter Oscilloscope  Measure

Connection of current cable

Explanation of current probe

Ignition primary current

Component operating current

Check Ignition system(Status of Power supply)

Check operating status of each component


Carman scan for ems professor

3.2 Repair by measuring pressure

3.2.1 Measurement of vaccum : 760mmHg - 0

(From atmospheric pressure to vaccum 1bar)

3.2.2 Measurement of pressure : 0 - 500 psi

(From atmospheric pressure to 35 bar)

How to connect Carman scan :

A and B channel can be used simultaneously. After connecting adapter to pressure line(measuring part), connect cable to converting module.

Carman scan mode : Please perform following procedure on the screen, -Vehicle scopemeter Multimeter PressureMeasure.

Measuring of vaccum : check MAP sensor and master back

Measuring of pressure: check fuel pump,regulator


Carman scan for ems professor

3.3 Repair by measuring Temp.

(Can be measured from -50°C to 1000 °C )

How to connect Carman scan :

Both Channel A and Bcan be used. After installing thermo couple, connect cable to converting module.

Carman scan mode : Please perform following procedure on the screen , -Vehicle scopemeter  MultimeterTemperature

Measurement of Temp. : Intake air Temp, Coolant Temp, Exhaust Gas Temp.


Carman scan for ems professor

4. Application of Simulation Function

4.1 Operating Sensor

4.2 Operating Actuator


Carman scan for ems professor

DRIVING

4.1 Operating Sensor

4.1.1 The Methodology of operating sensor with Carman scan

If Service data from Carman scan is strange, sending signal to the sensor directly, Check whether a problem of line or a problem of component.

How to connect Carman scan :

Can be used by B channel, connect cable to sensor

(+)---->signal line, (-)-----> GND (body of vehicle)

Carman scan mode : Please perform following procedure on the screen, -Vehicle scopemeter simulation operating with (+), (-) key

???


Carman scan for ems professor

Abnormal E/G running

No

Yes

Fault code ?

Sensor problem

Sensor problem

4.1.2 The flow of operating sensor with Carman scan

With this function, being able to distinguish exact cause between sensor and wire which is causing any abnormal engine running or fault.

Connector without sensor

Sending signal by Carman scan

Sending signal

Yes

No

Monitoring service data expected as a cause

Yes

No

Abnormal Service data ?

Sending signal by Carman scan

Sending signal by Carman scan

No

Disappeared fault code ?

Disappeared abnormal service Data ?

Yes

Yes

No

Disappeared abnormal E/G running ?

Yes

Wire problem

Other cause


Carman scan for ems professor

DRIVING

4.2 Operating Actuator

4.2.1 The Methodology of operating actuator with Carman scan

Although there is some problem at state of engine, No trouble code is showed at actuator system,(namely, No problem at actuator power but it is suspicious of operating well), Check it directly if actuator operates well.

How to connect Carman scan :

Can be used by A channel. connect (+) at cable for sensor to component operating line(-)

Carman scan mode : Please perform following procedure on the screen, Vehicle scope meter Actuator Operating with ‘driv’, ‘stop’key.

Connection cable to operating line

? ! ?


Carman scan for ems professor

Abnormal E/G running

No

Yes

Fault code ?

Actuator problem

Actuator problem

4.2.2 The flow of operating actuator with Carman scan

With this function, being able to distinguish exact cause between actuator and wire which is causing any abnormal engine running or fault.

Sending activation signal by Carman scan

Actuator without connector

Sending activation signal

Yes

No

Monitoring E/G running phenomenon

Yes

No

Any actuator related to problem ?

Sending activation signal by Carman scan

Sending activation signal by Carman scan

No

Disappeared fault code ?

E/G running is changed ?

Yes

Yes

No

Disappeared abnormal E/G running ?

Yes

Wire problem or actuator stick

Other cause


Carman scan for ems professor

5. Application of Special Maintenance

5.1 Compression pressure at

each cylinder

5.2 Battery charging status

5.3 Check if actuator is stuck


Carman scan for ems professor

5.1 Compression pressure at each cylinder

How to connect Carman scan :

Can be used by B channel, connect cable for large current to main line (Battery).

Carman scan mode : Please perform following procedure on the screen, -Vehicle scopemeter OscilloscopeMeasure

Connection current cable

Explanation of current probe

View compression pressure

Measure with CAM signal, first peak is NO1.Cylinder

it shows explosion oder of engine.

By comparison of height, compare pressure of each cylinder.


Carman scan for ems professor

5.2 Battery charging status

How to connect Carman scan :

Can be used by B channel, connect cable for large current to main line (Battery)

Carman scan mode : Please perform following procedure on the screen, -Vehicle scopemeter Oscilloscope  Measure.

Connection current cable

Explanation of current probe

View Cranking Current

Comparing the first peak current with CCA, if the value of peak is below 70% of CCA value, Judging “Battery charging status ” is lack.


Carman scan for ems professor

DRIVING

5.3 Check if Actuator operates well

Carman scan mode : Please perform following procedure on the screen, -vehicle scopemeter Actuator  operating ‘Driv’, ‘stop’ key

How to connect Carman scan :

Can be used by A channel, connect cable for sensor(+) to component operating line(power), (-)to GND.

Connecting cable to operating line

Check if RPM increases proportionally, when duty gets larger by Carman scan PRO. After disconnection of ISC probe.


Carman scan for ems professor

6. Carman scanUtilization chart (1/3)


Carman scan for ems professor

6. Carman scanUtilization chart (2/3)


Carman scan for ems professor

6. Carman scanUtilization chart (3/3)


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