Camshaft Adjustment Valve 1, Checking

Special Tools And Workshop Equipment Required 

• Multimeter.
• Wiring diagram.

Test Requirements 

• The Camshaft Adjustment Valve 1 -N205- 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 connections between engine/transmission/chassis OK.
• Ignition switched off.

Test Procedure 

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK 

Start Diagnosis 

-- Remove the engine cover with air filter. Refer to the appropriate Service Information.

-- 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 9.0 Ω (at approx. 20° C) 

If the specified value was Not obtained: 

-- Replace the Camshaft Adjustment Valve 1 -N205-. Refer to the appropriate Service 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 to engine ground 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 circuit to Ground.

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

-- If necessary, repair the faulty wiring connection. Replace any blown fuses.

If the specified value was Not 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) -J623-. Refer to the appropriate Service Information.

-- Using a multimeter, Check the Camshaft Adjustment Valve 1 -N205- electrical harness connector terminal to the Motronic Engine Control Module (ECM) electrical harness connector terminal for an open or high resistance.

Camshaft Adjustment Valve 1 -N205- electrical harness connector terminal	Motronic Engine Control Module (ECM) electrical harness connector T60 terminal or test box socket
2	5

Specified value: 1.5 Ω 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 not OK: 

-- Replace the Motronic Engine Control Module (ECM) -J623-. Refer to the appropriate Service Information.

-- Install the engine cover with air filter. Refer to the appropriate Service 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 .
2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .