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Renewing, coding and matching engine control unit > < Checking speedometer sender G22

Polo Mk3

Checking accelerator position senderG79
Checking accelerator position sender -G79-
The accelerator position sender -G79- is located on the accelerator pedal and passes the driver's requirement on to the control unit.
Special tools and workshop equipment required
t  Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- with diagnosis cable -V.A.G 1551/3-
t  Adapter cable (68-pin) -V.A.G 1598/18A- or adapter -V.A.G 1598/22-
t  Hand multimeter -V.A.G 1526C- or multimeter -V.A.G 1715-
t  Auxiliary measuring set -V.A.G 1594C-
t  Current flow diagram
Test procedure
–  Connect fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- and select engine electronics control unit with “address word 01”. The ignition must be switched on for this purpose. (Connect fault reader -V.A.G 1551- and select engine electronics control unit → Chapter.)
   
Indicated on display:
–  Press buttons 0 and 8 for function “Read measured value block” and confirm entry with Q button.
  
Rapid data transfer                 HELP
Select function XX
Indicated on display:
–  Press buttons 0, 0 and 2 for “Display group number 2” and confirm entry with Q button.
–  Check accelerator position display in display zone 2. The accelerator pedal must not be depressed.
  
Read measured value block           HELP
Input display group number XXX
Specification: 0.0%
–  In addition check the idling speed switch display in display zone 3. The middle position must show 1. Display: 010
  
Read measured value block 2          ->
0 rpm     0.0 %      0 1 0       18.4 °C
–  Depress accelerator pedal slowly until fully down, and observe display zones 2 and 3.
t  Display zone 2: The accelerator pedal position value must increase continuously. Specification at full throttle position: 100 %
t  Display zone 3: The middle position must change to 0. Display: 000
End specification value not achieved:
–  Press → button.
–  Press buttons 0 and 6 for function “End data transfer” and confirm entry with Q button.
–  Switch off ignition.
–  Adjust accelerator position sender -G79- → Chapter.
Display does not change or is erratic:
–  Check accelerator position sender -G79- as follows:
–  Press → button.
–  Press buttons 0 and 6 for function “End data transfer” and confirm entry with Q button.
–  Switch off ignition.
  
Read measured value block 2           ->
0 rpm     100.0 %     0 0 0      18.4 °C
–  Disconnect connector for accelerator position sender -G79--1-.
–  Measure resistance of sender between contacts 1+3 of connector.
Specification:
Accelerator pedal in idle position: 1.0…1.5 kΩ
Accelerator pedal in full-throttle position: 1.5…2.5 kΩ
–  Measure resistance between connector contacts 4+6.
Specification:
Accelerator pedal in idle position: Max. 1.5 kΩ
Accelerator pedal depressed: ∞ Ω
If the specifications are not achieved:
–  Renew accelerator position sender -G79- → Item
If the specifications are attained:
Engine code AGD (with 68-pin control unit)
  N23-0088
–  Connect adapter cable, 68-pin -V.A.G 1598/18A- to control unit wiring harness.
  V29-0062
–  Check lines between adapter cable (68-pin) -V.A.G 1598/18A- and connector for open circuit according to current flow diagram. Contact 1+socket 15 Contact 2+socket 57 Contact 3+socket 55 Contact 4+socket 65 Contact 5+socket 62 Contact 6+socket 33.
Cable resistance: max. 1.5 Ω.
Engine codes AGD (with 80-pin control unit), AHG, AKU
  N23-0017
–  Connect adapter -V.A.G 1598/22- to control unit wiring harness.
  N23-0197
–  Check lines between adapter -V.A.G 1598/22- and connector for open circuit according to current flow diagram. Contact 1+socket 24 Contact 2+socket 11 Contact 3+socket 23 Contact 4+socket 12 Contact 5+socket 8 Contact 6+socket 25.
Cable resistance: max. 1.5 Ω.
Continuation for all engine codes
–  Also check wiring for short to one another, short to vehicle earth and short to battery positive.
Specification: ∞ Ω.
If no fault in lines is detected:
–  Renew diesel direct injection system control unit -J248- → Chapter.
  N23-0017

Renewing, coding and matching engine control unit > < Checking speedometer sender G22