Variable Valve Timing Actuator: Testing and Inspection

Diagnostic Procedures

Camshaft Adjustment Valve, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Camshaft Adjustment Valve 1 (N205) fuse OK.

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

• 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 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. Refer to the Repair Information.

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

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

Specified value: 5.0 to 9.0 ohms (at approx. 20 °C)

If the specified value was Not obtained:

- Replace the Camshaft Adjustment Valve 1 (N205 ) Refer to the Repair Information.

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 for voltage.

- Switch the ignition OFF.

Specified value: Battery voltage.

If the specified value was Not obtained:

- Check the wiring connection for an open circuit, high resistance or short to ground. Refer to the wiring diagram.

- Check the wiring connection 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) ( J220). Refer to the Repair Information.

- 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 T121 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, high resistance, short circuit to Battery (+) or Ground.

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

- If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and voltage supply was OK:

- Replace the Motronic Engine Control Module (ECM) (J220). Refer to the Repair Information.

- Install the engine cover with air filter. 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 ] Readiness Code.