EGR Vacuum Regulator Solenoid Valve with Potentiometer, Checking

EGR Vacuum Regulator Solenoid Valve with 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 EGR Vacuum Regulator Solenoid Valve and High Pressure EGR Valve both refer to the same component N18 or V338. Name changes occur in wiring diagrams, parts listings etc. The EGR potentiometer G212 is part of the N18 or V338 valve 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 EGR/Potentiometer (N18/V338) electrical harness connector. Refer to Wiring Diagrams for Pin locations.

Checking internal resistance

- Using a multimeter, check the EGR/Potentiometer (N18/V338) terminals 2 to 6 for resistance.

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

- Using a multimeter, check the EGR/Potentiometer (N18/V338) terminals 1 to 5 for resistance.

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

If any of the specified values are Not obtained:

- Replace the EGR/Potentiometer (N18/V338).

If the specifications were obtained:

Checking voltage

- Switch the ignition On.

- Using a multimeter, check the EGR/Potentiometer (N18/V338) electrical harness connector terminal 2 to Ground for voltage.

- Using a multimeter, check the EGR/Potentiometer (N18/V338) electrical harness connector terminal 6 to Ground for voltage.

- Using a multimeter, check the EGR/Potentiometer (N18/V338) electrical harness connector terminal 3 to Battery Positive (+) for voltage.

Specified value for above tests: near Battery voltage.

- Using a multimeter, check the EGR/Potentiometer (N18/V338) electrical harness connector terminal 1 to Ground for voltage.

- Switch the ignition Off.

Specified value: Near 5.01 V

If any of the specified values were Not obtained:

- Check the EGR/Potentiometer (N18/V338) electrical harness to the Engine Control Module (ECM) (J623) for an for an open circuit or a short circuit. Refer to Wiring Diagrams for Pin locations.

- 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

- Remove the Engine Control Module (ECM) (J623). Refer to the Repair Information.

- Using a multimeter, check the EGR/Potentiometer (N18/V338) electrical harness connector terminal to the Engine Control Module (ECM) (J623) electrical harness connector T60 terminal for resistance. Refer to Wiring Diagrams for Pin locations.






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 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 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.