Bank 1 Exhaust Gas Temperature Sensor, Checking

Bank 1 Exhaust Gas Temperature Sensor, Checking

• Use only gold-plated terminals when servicing terminals in the electrical harness connector of Exhaust Gas Temperature (EGT) Sensor 1 (G235).

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Motronic Engine Control Module (ECM) (J623) fuses OK.

• The Fuel Pump (FP) Relay (J17) must be 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 ] Preliminary Check

Start diagnosis

Checking internal resistance

- Disconnect the Exhaust Gas Temperature (EGT) Sensor 1 (G235) electrical harness connector.

- Using a multimeter, check the Exhaust Gas Temperature (EGT) Sensor 1 (G235) terminals 1 to 2 for resistance.

Specified value: infinite ohms

If the specification was not obtained:

- Replace the Exhaust Gas Temperature (EGT) Sensor 1 (G235).

If the specification was obtained:

Checking Voltage supply

- Disconnect the Exhaust Gas Temperature (EGT) Sensor 1 (G235) electrical harness connector - 1 -.





- Switch the ignition on.

- Using a multimeter, check the Exhaust Gas Temperature (EGT) Sensor 1 (G235) electrical harness connector terminals 1 to 2 for voltage.





Specified value: 0.400 to 0.500 V.

- Switch the ignition off.

If any of the specified values was 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 => [ Engine Control Module, Removing and Installing ] Engine Control Module, Removing and Installing.

- Using a multimeter, check the Exhaust Gas Temperature (EGT) Sensor 1 (G235) electrical harness connector terminals to the Motronic Engine Control Module (ECM) (J623) electrical harness connector terminals for an open circuit.









Specified value: 1.5 ohms Max.

If the specification was not obtained:

- Check the wiring for a short circuit to each other, Battery (+), or 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 detected in the wiring:

- Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] 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 ] Readiness Code.

- End diagnosis.

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

- Replace the Motronic Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.

- Assembly is performed in the reverse of the removal.

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 ] Diagnostic Mode 03 - Read DTC Memory.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Readiness Code.