Camshaft Adjustment Valve, checking

This procedure is used to check the Camshaft Adjustment Valves N205 and N208.

Special tools, testers and auxiliary items required 

• Multimeter V.A.G 1526 A or equivalent.
• Voltage Tester VAG1527B or equivalent.
• Adapter Cable (121-Point) VAG1598/31.
• Connector Test Set VAG1594C.

Test requirements 

• Fuse for valve for camshaft adjustment OK..
• Ignition switched off.
• The Fuel Pump (FP) Relay J17 OK. → Fuel Pump (FP) Relay J17, checking .

Test sequence 

Cylinder bank 1 (right): 

• Disconnect electrical connector - 2  - from Camshaft Adjustment Valve 1 N205.

Cylinder bank 2 (left): 

• Remove screw - arrow  - retaining coolant reservoir.

• Disconnect electrical connector from Engine Coolant Level (ECL) Warning Switch F66 at the bottom of coolant reservoir and set aside the coolant reservoir with coolant hoses - 1  - and - 2  - connected.
• Disconnect electrical connector - 3  - from Camshaft Adjustment Valve 2 N208.

Checking internal resistance 

• Using Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for open circuit.

Specified value: 8 to 13 Ω.

If specified value is not obtained:

• Replace faulty Camshaft Adjustment Valve.

If specified value is obtained:

Checking voltage supply 

• Using Voltage Tester VAG1527B or equivalent, check the following wiring connection for voltage.

Harness connector Terminal	Measure to
1	Engine Ground (GND)

• Operate starter briefly:

LED must light up.

• Switch ignition off.

If LED does not light up:

• Check wiring connection from terminal 1 of the electrical harness connector via fuse to Motronic Engine Control Module (ECM) Power Supply Relay J271 terminal 2 for an open circuit:

Specified value: Wire resistance max 1.5 Ω.

If specified value is not obtained:

• Check wiring for a short circuit to Battery positive (+) or an open circuit.
• If necessary, repair wiring connection.

If LED lights up.

Checking activation 

• Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of Engine Control Module (ECM) J623 ; the ECM is not connected. → Diagnostic tester, connecting .

• Using Adapter Cable (121-Point) VAG1598/31 and Multimeter V.A.G 1526 A or equivalent, check the following wiring connections for an open circuit.

• Camshaft Adjustment Valve 1 N205 (bank 1).

Harness connector Terminal	Test box Socket
2	115

• Camshaft Adjustment Valve 2 N208 (bank 2).

Harness connector Terminal	Test box Socket
2	120

If specification is not obtained:

• Check wiring for a short circuit to Battery positive (+) or an open circuit.
• If necessary, repair wiring connection.

If no malfunctions are found in the wiring:

• Replace Engine Control Module (ECM) J623. → Engine Control Module (ECM) J623, replacing .

If no malfunctions are detected:

• Replace mechanical camshaft adjuster. → 15 - ENGINE - CYLINDER HEAD, VALVETRAIN .

Assembly is performed in reverse order of removal. Note the following:

Final procedures 

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

1. Check DTC memory..
2. If necessary, erase DTC memory..
3. If DTC memory was erased, generate readiness code..

• End diagnosis and switch ignition off.