Throttle Position Sensor/Accelerator Pedal Position Sensor 2, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram

Test requirement 

• The Motronic Engine Control Module (ECM) - J220- 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 connections between engine/transmission/chassis OK.

Test procedure 

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

Start diagnosis 

-- Remove the drivers side storage compartment. Refer to the Repair information

-- Disconnect the Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185- 6 pin electrical harness connector -2-.

Checking voltage supply and wiring 

-- Switch the ignition ON.

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

Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185- electrical harness connector terminals	Specified value
1 to Ground	near 5 V
1 to 5	near 5 V
2 to Ground	near 5 V
2 to 3	near 5 V

-- Switch the ignition OFF.

If the specified value was Not obtained:

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 Motronic Engine Control Module (ECM) -J220-. Refer to the Repair information.

-- Using a multimeter, check the Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185- electrical harness connector terminals to the Motronic Engine Control Module (ECM) -J220- electrical connector T121 for an open circuit.

Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185- electrical harness connector terminals	Motronic Engine Control Module (ECM) -J220- electrical connector T121 terminals or test box sockets
1	72
2	73
3	36
4	35
5	33
6	34

Specified value: 1.5 Ω max.

If the specified value was Not obtained:

-- Check the wiring for a short circuit to each other, Battery (+) or Ground or high resistance.

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

-- If necessary, repair the faulty wiring connection.

If no fault is detected in the wiring and the voltage supply was OK:

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

If no fault is detected in the wiring and the voltage supply was Not OK:

-- Replace the Motronic Engine Control Module (ECM) -J220-. Refer to the Repair information.

-- Install the drivers side storage compartment.

Final procedures 

After the 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 .