Checking accelerator pedal position sender -G79 and -G185 — AUDI

The two senders -G79 and -G185 are located at the accelerator pedal and each sender relays the driver input separately to the engine control unit. Both senders are accommodated in a joint housing.

Connect vehicle diagnostic, testing and information system VAS 5051 or fault reader V.A.G 1551 and select engine electronics control unit with "address word" 01 => Page
01-8
.
Ignition must be on.

Rapid data transfer
HELP
Select function XX
Indicated on display:

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

Read measured value block
Q
Enter display group number
XXX
Indicated on display:

Press keys 0, 6 and 2 for "Display group number 62" and confirm entry with Q key.

Read measured value block 62
⇒
1
2
3
4
Indicated on display:

Check specifications for electronic throttle system potentiometer voltages.

Display zones
1 · 2 · 3 · 4
Display group 62: Electronic throttle system potentiometer voltages with ignition on
Display · xx % · xx % · xx % · xx %
Readout · Throttle valve angle / (angle sender 1) · Throttle valve angle / (angle sender 2) · Accelerator pedal position / sender · Accelerator pedal position / sender 2
Operating range · min.: 0 % / max.: 100 % · min.: 0 % / max.: 100 % · min.: 0 % / max.: 100 % · min.: 0 % / max.: 100 %
Specification · 3...93 % · 97...3 % · 12...97 % · 4...49 %

Note:

The engine control unit converts the angle sender voltage values into percentages referenced to 5 V and displays the percentage values (5 V supply voltage corresponds to 100 %).

Observe display zones 3 and 4.
Slowly floor accelerator pedal.

The percentage value displayed in zone 3 must increase steadily. The tolerance range 12...97 % is not fully utilised.

The percentage value displayed in zone 4 must likewise increase steadily. The tolerance range 4...49 % is not fully utilised.

Note:

The value displayed in zone 3 must always be roughly twice that in display zone 4.

If displays are not as described:

Check power supply and wiring of accelerator pedal position senders =>Page
24-174
.

Checking power supply of accelerator pedal position senders

Unplug accelerator pedal position sender connector.

Note:

Connector is clipped in at pedal bracket next to brake light switch.

Left-hand drive vehicles:

Switch on ignition.
Connect portable multimeter for voltage measurement to the following connector sockets:

6-pin connector at wiring harness, socket · Specification
1 + earth · approx. 5 V
1 + 5 · approx. 5 V
2 + earth · approx. 5 V
2 + 3 · approx. 5 V

Right-hand drive vehicles:

Switch on ignition.

Connect portable multimeter for voltage measurement to the following connector sockets:

6-pin connector at wiring harness, socket · Specification
2 + earth · approx. 5 V
2 + 3 · approx. 5 V
5 + earth · approx. 5 V
5 + 4 · approx. 5 V

All models:

If readings match specifications:

Additionally check signal wires => Page
24-176
.

If readings do not match specifications:

Check wiring between engine control unit and accelerator pedal position senders => Page
24-176
.

Checking signal wires and wiring between accelerator pedal position senders and engine control unit

Connect test box V.A.G 1598/31 to engine control unit wiring harness. Actual engine control unit is not to be connected=>Page
24-12
.

Left-hand drive vehicles:

Check for open circuit and short to earth/positive in the following wiring:

Connector, / socket · Test box V.A.G 1598/31, / socket
1 · 72
2 · 73
3 · 36
4 (signal wire) · 35
5 · 33
6 (signal wire) · 34

Right-hand drive vehicles:

Check for open circuit and short to earth/positive in the following wiring:

Connector, / socket · Test box V.A.G 1598/31, / socket
1 (signal wire) · 35
2 · 73
3 · 36
4 · 33
5 · 72
6 (signal wire) · 34

All models:

If necessary, eliminate open circuit in wiring/short circuit.

If no fault is found in wiring:

Replace accelerator pedal position senders.

=> Fuel Supply System - Petrol Engines; Repair Group 20; Servicing Accelerator Mechanism - Right-hand drive vehicles
Fuel Supply System - Petrol Engines
Servicing Accelerator Mechanism - Right-hand drive vehicles