Throttle Position Sensor And Accelerator Pedal Position Sensor 2, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram

Test requirement

• The Motronic 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 connections between engine/transmission/chassis OK.
• Ignition off

Test procedure 

-- Observe safety precautions. Refer to SAFETY PRECAUTIONS 

-- Observe Clean Working Conditions. Refer to CLEAN WORKING CONDITIONS 

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

Start diagnosis 

Test sequence 

-- Remove the steering column cover.

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

Checking voltage supply and wiring 

-- Switch the ignition on.

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

Throttle Position (TP) Sensor -G79- /OR Kick Down Switch/Closed Throttle Position Sw -G185-, checking	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 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 Motronic Engine Control Module (ECM) -J623-. 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) -J623- electrical connector T94 for resistance.

Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185- Electrical harness connector	Motronic Engine Control Module (ECM) -J623- Electrical harness connector T94 terminals or test box socket
1	58
2	80
3	78
4	79
5	56
6	57

Specified value: 1.5 Ω max.

If the specified value is not obtained:

-- Check the wiring for high resistance, an open or a short to voltage or ground.

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

-- If necessary, repair the faulty wiring connection.

-- 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:

Generate readiness code. Refer to READINESS CODE .

If the DTC does return, no malfunction is detected in the wiring and the voltage supply is OK:

-- Replace the Motronic Engine Control Module (ECM) -J623-. Refer to the Repair information.

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

Final procedures 

After repair work, the following work steps must be performed in the mentioned 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 .