Checking accelerator pedal position sender (80-pin control unit) — VW

Special tools, workshop equipment, test and measuring appliances and auxiliary items required

V.A.G 1526 Hand multimeter
V.A.G 1594 A Adapter set
V.A.G 1598/22 Test box
Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
Current flow diagram

Test sequence

Connect fault reader V.A.G 1551 (V.A.G 1552) and with ignition switched on select engine electronics control unit with the "Address word" 01:

=> Repair group 01; Self-diagnosis; Connecting fault reader V.A.G 1551 and selecting engine electronics control unit
4-cyl. diesel engine Mechanics
Self-diagnosis
Connecting fault reader V.A.G 1551 and selecting engine electronics control unit

Rapid data transfer
HELP
Select function XXX
Indicated on display:

Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

Read measured value block
HELP
Input display group number XXX
Indicated on display:

Press keys 0, 0 and 2 for "Display group number 2" and confirm entry with Q key.
Read measured value block 2
⇒
0 rpm
0.0 %
0 1 0
18.4 5C
Check accelerator pedal position display in display zone 2. The accelerator pedal must not be depressed.
Specification: 0.0 %
In addition check the idling speed switch display in display zone 3. The centre position must show 1.
Display: 010
Read measured value block 2
⇒
0 rpm
100.0 %
0 0 0
18.4 5C
Depress accelerator pedal slowly until fully down, and observe display zones 2 and 3.
Display zone 2:
The accelerator pedal position figure must increase continuously.
Specification at full throttle position: 100.0 %
Display zone 3:
The centre position must change to 0.
Display: 0 0 0

End specification value not achieved:

Press the ⇒key.
Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.
Switch off ignition.
Adjust accelerator pedal position sender
=>Page
20-23

Display does not change or is erratic:

Check accelerator pedal position sender as follows:
Press the ⇒key.
Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.
Switch off ignition.

Separate connector for accelerator pedal position sender -1-.

Measure sender resistance between connector contacts 1+3.
Specification:
Accelerator pedal in idling speed position: 1.0...1.5 kω
Accelerator pedal in full throttle position: 1.5...2.5 kω
Check idling speed switch (F60) in accelerator pedal position sender. To do this measure resistance between connector contacts 4+6.
Specification:
Accelerator pedal in idling speed position: max.1.5 kω
Accelerator pedal depressed: ∞ ω

If the specifications are not obtained:

Renew accelerator pedal position sender (G79)
=>Page
20-16
.

If the specifications are obtained:

Connect test box V.A.G 1598/22 to control unit wiring harness.

Check wiring between test box 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
Wire resistance: max. 1.5 ω

Additionally check wires for short to one another, to vehicle earth and to battery positive.
Specification: ∞ω

If no fault is detected in the wiring:

Renew Diesel direct injection system control unit (J248)

=> Repair group 23; Renewing engine control unit, coding and matching; Renewing engine control unit
4-cyl. diesel engine Mechanics
Renewing engine control unit, coding and matching
Renewing engine control unit