slide1
Download
Skip this Video
Download Presentation
Motor Vehicle Level 3

Loading in 2 Seconds...

play fullscreen
1 / 18

Motor Vehicle Level 3 - PowerPoint PPT Presentation


  • 110 Views
  • Uploaded on

Motor Vehicle Level 3. Resource 4. ABS Sensors Their Operation and Waveform Produced. Motor Vehicle Level 3 Resource 4. ABS Sensors Their Operation and Waveform Produced. Aims. To recognize various sensors used within ABS systems and their role within the system.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Motor Vehicle Level 3' - cianna


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Motor Vehicle Level 3

Resource 4

ABS Sensors Their Operation and Waveform Produced

slide2

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Aims

To recognize various sensors used within ABS systems and their role within the system

slide3

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Objectives

By the end of this session you will be able to:

  • Identify various sensors including hall, and be able to describe passive and inductive sensors and their operation
  • Recognize the role of the speed sensor and it\'s location
  • Recognize and comment on the waveforms produced.
  • Comment briefly on how to maintain the sensor, and identify possible faults.
slide4

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Types of sensor : Active Sensor

  • Example:-Magnetised pick up (crankshaft sensor, ABS sensor)
  • Voltage signal produced is sent to the input of the ECU for analysation.
  • The ECU will covert this Analogue signal to Digital signal which the ECU can read.
  • The ECU will now react (alter the brake pressure depending on this voltage signal.
slide5

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Types of sensor : Passive Sensor (three wire)

  • Three wire device
  • Supply voltage for the sensor is supplied via the ECU
  • The internal resistance alters with a change in environment these are usually used to sense movement (i.e. throttle position)
  • This is measured by the ECU and the ECU will alter accordingly
slide6

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Types of sensor : Passive Sensor (two wire device)

  • Similar to a three wire device, the sensors internal resistance will alter with a change in environment rather than change in movement (i.e. engine coolant)
  • ECU Supplies voltage to the sensor,
  • The ECU will measure the change in internal resistance and react accordingly.
slide7

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

ABS Sensors

  • Of course, ABS will use an active sensor
  • Why do you think that is?
  • Could it use a passive sensor?
slide8

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

ABS Wheel Speed Sensor

  • Wheel Speed Sensors are mounted at each wheel and sends a rotation signal to the ECU
  • Wheel speed sensors can be mounted to the steering knuckle or to the axle carrier
slide9

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

ABS Wheel Speed Sensor

slide10

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

ABS Wheel Speed Sensor

  • As the teeth of the sensor rotor pass the iron core, magnetism will cut through the coil windings Inducing a voltage
  • When the tooth is centered to the iron core 0v is produced
  • As the tooth moves away from the iron core, the magnetic field expands producing a negative voltage
  • As the wheel rotates faster the voltage and frequency increase (indicating to the ECU that the vehicle is travelling faster)
slide11

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Waveform produced

  • In order to diagnose a fault within an ABS system waveforms are useful in order to determine system performance, and will also give hints as to the problem.
slide12

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Waveform produced

  • The following images where taking using a diagnostic tool called a Picoscope
  • These show two wheel speed sensors being monitored, one has a fault...is it the red trace or the blue trace?
slide13

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Waveform produced

slide14

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Waveform produced

  • this small capture taken from the waveform produced indicates a fault compared with the blue trace
  • The fact the we have a waveform at all indicates that the sensor is producing a signal.
  • Therefore, we can diagnose that the rotor wheel has failed.
slide15

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Waveform produced

  • This vehicle measures rear wheel speed via a driveshaft, upon inspection, we can see that the teeth have been damaged, furthermore, we can see this corresponds to our waveform produced.
  • Another factor that could have produced a similar waveform could have been distance from the sensor to the rotor or contamination of the sensor.
slide16

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Waveform produced

  • In order to check the voltage is correct to the sensor
  • Ensure that your multimeter is correct and on the correct function (direct v)
  • Measure between the terminals as shown (always refer to manufactures guidelines)
  • The voltage should be between 10v-14v
slide17

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Probing a Sensor

  • Continuity check
  • Is done to check that there is no faults in the wiring harness between the ECU, the Actuator and the ABS relays and possibly to the sensors.
  • Refer to manufactures guidelines
  • From the signal contact in the terminal blocks check the resistance between each components.
  • The resistance should be around 4-6Ώ
slide18

Motor Vehicle Level 3Resource 4

ABS Sensors Their Operation and Waveform Produced

Summary

Have We:-

  • Identified various sensors including hall, and be able to describe passive and inductive sensors and their operation
  • Recognized the role of the speed sensor and it\'s location
  • Recognized and commented on the waveforms produced.
  • Commented briefly on how to maintain the sensor, and identify possible faults.
ad