Variable Valve Timing Actuator: Testing and Inspection

Camshaft Adjustment Valve, Checking

This procedure is used to check the Camshaft Adjustment Valves (N205, N208, N318, N319).

• Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Camshaft Adjustment Valves (N205, N208, N318, N319).

Special tools, testers and auxiliary items required

• Multimeter.

• Diode test lamp.

• Wiring diagram.

Test requirements

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

• Engine Control Module (ECM) Power Supply Relay (J363) OK.

• Battery voltage at least 12.5 V.

• 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 customer's complaint. Refer to => [ Preliminary Check ] Preliminary Check.

• Voltage for camshaft adjustment solenoid valves is supplied through the the Engine Control Module (ECM) Power Supply Relay (J363).

Cylinder bank 1 (right):





- Disconnect the electrical harness connectors from Camshaft Adjustment Valve 1 (exhaust) (N318)- 1 - and Camshaft Adjustment Valve 1 (N205)- 2 -.

Cylinder bank 2 (left):





- Remove the screw - arrow - retaining the coolant reservoir.

- Disconnect the electrical connector from Engine Coolant Level (ECL) Warning Switch (F66) at the bottom of the coolant reservoir and set aside the coolant reservoir with the coolant hoses - 1 - and - 2 - connected.





- Disconnect the electrical harness connectors from Camshaft Adjustment Valve 2 (exhaust) (N319)- 3 - and Camshaft Adjustment Valve 2 (N208)- 2 -.

Checking internal resistance





- Using a Multimeter, check the relevant Camshaft Adjustment Valve electrical terminals 1 to 2 for resistance.

Specified value: 8 to 13 ohms.

If specified value is not obtained:

- Replace the respective Camshaft Adjustment Valve

If specified value is obtained:

Checking voltage supply

- Using the Diode test lamp , check the following wiring connection for voltage according to the wiring diagram.









- Switch ignition on.

LED must light up.

If LED does not light up:

- Check wiring connection from terminal 1 of the Camshaft Adjustment Valve electrical harness connector through the fuse to the Engine Control Module (ECM) Power Supply Relay (J363) electrical harness connector terminal 2/87 for an open circuit according to wiring diagram:

Specified value: 1.5 ohms max.

- If necessary, repair the wiring connection.

If voltage supply is OK:

Checking wiring

If the manufacturers test box is being used, perform the following step.

- Install the test box (VAG1598/42).

If the manufacturers test box is not being used, perform the following step.

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





- Using a Multimeter, Check the Camshaft Adjustment Valve electrical harness connector to the Engine Control Module (ECM) (J623) electrical harness connector for resistance.

• Camshaft Adjustment Valve 1 (N205) (bank 1).





• Camshaft Adjustment Valve 1 (exhaust) (N318)(bank 1).





• Camshaft Adjustment Valve 2 (N208) (bank 2).





• Camshaft Adjustment Valve 2 (exhaust) (N319) (bank 2).





Specified value: 1.5 ohms max.

If the specification is not obtained:

- Check the wiring for a short circuit to Battery positive (+) or an open circuit.

- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring:

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

If no malfunctions are detected:

- Replace the relevant Camshaft Adjustment Valve

Assembly is performed in the reverse order of removal.

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 ] Monitors, Trips, Drive Cycles and Readiness Codes.