computers and input sensors
Download
Skip this Video
Download Presentation
COMPUTERS AND INPUT SENSORS

Loading in 2 Seconds...

play fullscreen
1 / 20

COMPUTERS AND INPUT SENSORS - PowerPoint PPT Presentation


  • 118 Views
  • Uploaded on

COMPUTERS AND INPUT SENSORS. CHAPTER 8. VOLTAGE SIGNALS. Pg 153C. ANALOG VOLTAGE SIGNALS VARIABLE VOLTAGE SIGNAL COMPUTERS INPUTS ARE USUALLY ANALOG TYPE SIGNALS EASY TO DIAGNOSE WITH DVOM DIRECT CURRENT OR ALTERNATING CURRENT. DIGITAL VOLTAGE SIGNALS. Pg 154C.

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 ' COMPUTERS AND INPUT SENSORS' - heman


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
voltage signals
VOLTAGE SIGNALS

Pg 153C

  • ANALOG VOLTAGE SIGNALS
    • VARIABLE VOLTAGE SIGNAL
    • COMPUTERS INPUTS ARE USUALLY ANALOG TYPE SIGNALS
    • EASY TO DIAGNOSE WITH DVOM
    • DIRECT CURRENT OR ALTERNATING CURRENT
digital voltage signals
DIGITAL VOLTAGE SIGNALS

Pg 154C

  • VOLTAGE IS EITHER HIGH OR LOW IN A GIVEN TIME PERIOD
  • COMPUTER USES AND PROCESSES INFORMATION IN DIGITAL LANGUAGE (BINARY 0 or 1)
  • SOME INPUTS PRODUCE A SQUARE WAVE SIGNAL
computer operation

Pg 155C

COMPUTER OPERATION
  • INPUT CONDITIONING
    • AMPLIFICATION
    • ANALOG TO DIGITAL CONVERSION
    • SOME A/D CONVERTER EXTERNAL TO MAIN PROCESSOR. (LIKE FORD PROGRAMMABLE SPEED ONLY MEMORY - PSOM)
computer memory
COMPUTER MEMORY

Pg 159C

  • RAM - RANDOM ACCESS MEMORY
    • TEMPORARY STORAGE
    • VOLATILE OR NON-VOLATILE
  • ROM - READ ONLY MEMORY
  • PROM - PROGRAMMABLE READ ONLY MEMORY
    • TELLS MICROPROCESSOR HOW VEHICLE IS EQUIPPED
computer programmed strategy
COMPUTER PROGRAMMED STRATEGY

Pg 160C

  • OPEN LOOP - CLOSED LOOP
  • ADAPTIVE STRATEGY
    • ABILITY OF COMPUTER TO LEARN FROM PAST EXPERIENCE.
    • COMPENSATES FOR WEAR
      • Will lose learned strategy if:
        • BATTERY DISCONNECTED
        • WHEN MAJOR COMPONENT REPLACED
        • NEW VEHICLE
input processing
INPUT PROCESSING
  • ROM LOOK UP TABLES (Pg 162C)
  • COMPUTER TAKES ALL INPUT INFO BEFORE MAKING DECISION
  • ONE WIRE INPUT (Pg 140L & 154L)
  • TWO WIRE INPUT (Pg 142L & 143L)
  • THREE WIRE INPUT (Pg 144L)
  • FOUR WIRE INPUT (Pg 146L)
pinpoint testing
PINPOINT TESTING
  • MOST REPAIR MANUALS TELL TO CAUSE OPPOSITE CODE
  • OHMMETER VS. VOLTMETER
  • FREQUENCY INPUT TESTING
  • LAB SCOPE USE
  • BLOCK LEARN - INTEGRATOR
oxygen sensors
OXYGEN SENSORS
  • 1,2,3,4 Wire s
  • EGO, HEGO
  • Lean Low Volts
  • Rich High Volts
  • Zirconia Type
  • Titania Type
  • DVOM or Lab Scope Only!!!

PAGE 168C

ect act sensors
ECT/ACT SENSORS

PG 142L

  • THERMISTORS HIGH RESISTANCE COLD AND LOWER RESISTANCE HOT
throttle position sensors tps
THROTTLE POSITION SENSORS (TPS)

PG 145L

  • ROTARY AND LINEAR
  • MUST BE SMOOTH VOLTAGE CHANGE
  • BEST TO USE A LAB SCOPE FOR TEST
throttle switch
THROTTLE SWITCH

Pg 146L

  • Four Wire Sensor
  • Used on alot of Foreign Cars and Trucks
  • Adjustment is critical
  • Some switches used as Fuel Pump Shut Off
manifold absolute pressure sensor
MANIFOLD ABSOLUTE PRESSURE SENSOR

Pg 147L

  • Senses differences between atmospheric pressure and manifold vacuum.
  • Must use specialized equipment to test
  • Sometimes used for BARO Input information
mass air flow sensors
VANE TYPE

Commonly used on foreign Cars

Test with DVOM or Lab Scope

Plate movement proportional to Air Flow

Other Inputs

HOT WIRE TYPE or GRID TYPE

Use Frequency Test

Map Frequency should always be a straight line transition with rpm.

Tap Test

MASS AIR FLOW SENSORS

Pg 151L

Pg 152L

knock sensors
KNOCK SENSORS
  • PIEZOELECTRIC CRYSTAL
  • Produces a frequency and changes it to a voltage before sending to PCM
  • TAP TEST, DVOM, FREQ or OHMMETER
egr sensors
EGR SENSORS

Pg 154L

Pg 317L

  • EVP Linear Sensor
  • Must test mechanical and electrical
  • Many different types of EGR & ``EGR Controls and EGR Sensors
  • Most EVP’s send a Analog signal
  • Lots of Driveability Problems
  • EGR problems can be caused by other Inputs
vehicle speed sensors
VEHICLE SPEED SENSORS
  • AC SIGNAL (ANALOG)
  • LOCATED DIFFERENT PLACES
  • SPEED BUFFER OR PSOM
  • CAN CAUSE TCC, CRUISE, SPEEDOMETER PROBLEMS
outputs
OUTPUTS
  • ACTUATORS
    • SOLENOIDS
    • RELAYS
    • DISPLAYS
  • CONTROLLED BY DRIVERS
  • TRANSISTORS OR GROUPS OF TRANSISTORS
ad