Exhaust Gas Recirculation Motor and EGR Potentiometer, Checking

Exhaust Gas Recirculation Motor and EGR Potentiometer, Checking

Observe all safety precautions: => [ Safety Precautions ] Safety Precautions

View clean working conditions: => [ Clean Working Conditions ] Clean Working Conditions

Perform a preliminary check to verify the condition: => [ Preliminary Check ] Preliminary Check.

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

• The Exhaust Gas Recirculation Motor and EGR Potentiometer both refer to the same component (V338). Name changes occur in wiring diagrams, parts listings etc. The EGR potentiometer G212 is part of the V338 motor assembly and is serviced as one component.

Special tools, testers and auxiliary items required

• Multimeter

• Electrical connector test lead set

Test conditions

• Fuse OK

• Battery voltage 12.5 V

• Ignition switched off

Start diagnosis

- Disconnect the Exhaust Gas Recirculation (EGR) Motor (V338/G212) electrical harness connector.

Checking internal resistance

- Using a multimeter, check the Exhaust Gas Recirculation (EGR) Motor (V338/G212) terminals 2 to 6 for resistance.

Specified value: 18.5 ohms (+/- 1.3 ohms).

- Using a multimeter, check the Exhaust Gas Recirculation (EGR) Motor (V338/G212) terminals 1 to 5 for resistance.

Specified value: 175.6 ohms (+/- 20 ohms).

If any of the specified values are Not obtained:

- Replace the Exhaust Gas Recirculation (EGR) Motor (V338/G212).

If the specifications were obtained:

Checking voltage

- Switch the ignition on.

- Using a multimeter, check the Exhaust Gas Recirculation (EGR) Motor (V338/G212) electrical harness connector terminal 2 to Ground for voltage.

- Using a multimeter, check the Exhaust Gas Recirculation (EGR) Motor (V338/G212) electrical harness connector terminal 6 to Ground for voltage.

- Using a multimeter, check the Exhaust Gas Recirculation (EGR) Motor (V338/G212) electrical harness connector terminal 3 to Battery Positive (+) for voltage.

Specified value for above tests: near Battery voltage.

- Using a multimeter, check the Exhaust Gas Recirculation (EGR) Motor (V338/G212) electrical harness connector terminal 1 to Ground for voltage.

Specified value: Near 5.01 V

If any of the specified values were Not obtained:

- Check the Exhaust Gas Recirculation (EGR) Motor (V338/G212) electrical harness to the Motronic Engine Control Module (ECM) (J623) for an for an open circuit or a short circuit.

- Check the wiring connections for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If the specified value was 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 Exhaust Gas Recirculation (EGR) Motor (V338/G212) electrical harness connector terminal to the Motronic Engine Control Module (ECM) (J623) electrical harness connector T60 terminal for resistance.






Specified value: 1.5 ohms Max.

If the specification was not obtained:

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

- If necessary, repair the faulty wiring connection.

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

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

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

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 Modes 01 - 0A.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 0A.

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