Variable Valve Timing Actuator: Testing and Inspection

Camshaft Adjustment Valve 1, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• Fuse (SB38) fuse OK.

• Motronic Engine Control Module (ECM) Power Supply Relay (J271) 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.

• Ignition switched off.

Test procedure

- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check.

Start diagnosis

- Remove the engine cover with air filter.

- Disconnect Camshaft Adjustment Valve 1 (N205) electrical harness connector - 1 -.





- Using a Multimeter, check the Camshaft Adjustment Valve 1 (N205) for resistance.





Specified value: 5.0 to 8.0 ohms (at approx. 20° C)

If the specified value was not obtained:

- Replace the Camshaft Adjustment Valve 1 (N205).

If the specified value was obtained:

Checking voltage

- Switch the ignition on.

- Using a Multimeter, check the Camshaft Adjustment Valve 1 (N205) electrical harness connector terminal 1 to Ground (GND) for voltage.

- Switch the ignition off.





Specified value: battery voltage.

If the specified value was not obtained:

- Check the Camshaft Adjustment Valve 1 (N205) electrical harness connector terminal 1 to the Motronic Engine Control Module (ECM) Power Supply Relay (J271) socket 2/87 for an open circuit, short circuit to Battery (+) or Ground (GND).

- Check the wiring connection for damage, corrosion, lose 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) (J220). Refer to => [ Engine Control Module ] Engine Control Module.

- Using a Multimeter, Check the Camshaft Adjustment Valve 1 (N205) electrical harness connector terminal 2 to the Motronic Engine Control Module (ECM) electrical harness connector T60 terminal 20 for an open circuit.









Specified value: 1.5 ohms Max.

If the specified value was not obtained:

- Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).

- Check the wiring connection for damage, corrosion, lose or broken terminals.

- If necessary, repair the faulty wiring connection.

- 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) (J220). Refer to => [ Engine Control Module ] Engine Control Module.

After the repair work, the following work steps must be performed in the following sequence:

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.