Throttle Position Sensor G79 And Accelerator Pedal Position Sensor 2 G185, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram

Test requirement

• The Engine Control Module (ECM) - J623- fuses OK.
• Battery voltage at least 12.5 volts.
• All electrical consumers such as, lights and rear window defroster, switched off.
• Vehicles with automatic transmission, shift selector lever into position "P" or "N".
• A/C switched off.
• Ground (GND) connections between engine/transmission/chassis OK.

Test procedure

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .

Start diagnosis

-- Using a screwdriver, remove the steering column cover -arrows-.

Fig 1: Identifying Steering Column Cover

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Disconnect the Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185- electrical harness connector -2-.

Fig 2: Connecting Wiring And Electrical Harness Connector To Accelerator Pedal Module

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Checking voltage supply

-- Switch the ignition on.

-- Using a Multimeter --, check the following wiring connections for voltage.

Fig 3: 6-Pin Electrical Harness Connector & Terminals

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Switch the ignition off.

If the specified values were obtained:

-- Replace the Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185-.

If any of the specified values were not obtained:

Checking wiring

If the manufacturers test box is being used. Perform the following step.

-- Install the test box.

If the manufacturers test box is not being used. Perform the following step.

-- Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

-- Using a Multimeter --, check the Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical connector T121 for resistance.

Fig 4: 6-Pin Electrical Connector & Terminals

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Specified value: 1.5 Ω max.

If the specification is not obtained:

-- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

-- If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and the voltage supply was OK:

-- Replace the Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185-.

If no malfunction is found in wiring:

-- Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .

-- Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

-- End diagnosis.

If the DTC returns and no malfunction is found in the wiring and voltage supply was OK:

-- Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

-- Assembly is performed in the reverse of the removal.

Final procedures

After repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .

End of diagnosis