Variable Valve Timing Actuator: Testing and Inspection
Diagnostic Procedures
Camshaft Adjustment Valve 1 Intake N205, Adjustment Valve 1 Exhaust N318 Checking
The following procedure is used to diagnose Camshaft Adjustment Valve 1 Intake (N205) and Camshaft Adjustment Valve 1 Exhaust (N318)
Special tools, testers and auxiliary items required
• Multimeter.
• Wiring diagram.
Test requirements
• The Camshaft Adjustment Valve 1 Intake (N205) and Camshaft Adjustment Valve 1 Exhaust (N318) 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
- Observe safety precautions. Refer to => [ Safety Precautions ] Safety Precautions
- Observe Clean Working Conditions. Refer to => [ Clean Working Conditions ] Clean Working Conditions
- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check.
Procedure
- Disconnect Camshaft Adjustment Valve 1 Intake (N205) electrical harness connector or Camshaft Adjustment Valve 1 Exhaust (N318).
- Using a multimeter, check the Camshaft Adjustment Valve 1 Intake (N205) or Camshaft Adjustment Valve 1 Exhaust (N318) for resistance.
- Measure from pin 1 to pin 2 of the appropriate adjustment valve solenoid.
Specified value: 10.0 to 13.0 ohms (at approx. 20° C)
If the specified value was not obtained:
- Replace the Camshaft Adjustment Valve 1 Intake (N205) or Camshaft Adjustment Valve 1 Exhaust (N318).
If the specified value was obtained:
Checking voltage
- Switch the ignition on.
- Using a multimeter, Check the Camshaft Adjustment Valve 1 Intake (N205) or Camshaft Adjustment Valve 1 Exhaust (N318) electrical harness connector terminal 1 to ground for voltage.
- Switch the ignition off.
Specified value: battery voltage.
If the specified value was not obtained:
- Check the wiring connection from terminal 1 to fuse 8 in Fuse Panel B 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.
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) (J623). Refer to the Repair Information.
- Using a, Check the Camshaft Adjustment Valve 1 Intake (N205) or Camshaft Adjustment Valve 1 Exhaust (N318) electrical harness connector terminal 2 to the Motronic Engine Control Module (ECM) electrical harness connector 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 or short circuit to voltage or ground.
- Check the wiring connection for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.
- Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.
- Perform a road test to verify repair.
If the DTC does not return:
Generate readiness code. Refer to => [ Readiness Code ] Readiness Code.
If the DTC does return, no malfunction is detected in the wiring and the voltage supply is OK:
- Replace the Motronic Engine Control Module (ECM) (J623). Refer to the Repair Information.
- Assembly is performed in the reverse of the removal.
Final procedures
After repair work, the following work steps must be performed in the mentioned 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.