Variable Valve Timing Actuator: Testing and Inspection

Camshaft Adjustment Valve (Vehicles With Engine Code AUG, AWM), Checking

Function
The camshaft adjustment is load- and RPM dependent. The electrical valve for camshaft adjustment switches oil pressure onto camshaft adjuster (mechanical adjustment mechanism), which adjusts the camshaft.

Recommended special tools and equipment
- V.A.G 1526 portable multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram

Test requirements






- The respective fuses of the Valve -1- for camshaft adjustment -N205- must be OK
- Fuel Pump (FP) Relay -J17- must be OK, check
- Battery voltage must be at least 11.5 volts.
- All electrical consumers such as, lights and rear window heating must be switched off.
- Parking brake must be engaged or else daylight driving lights will be switched on.
- If vehicle is equipped with an A/C system, it must be switched off.
- Ground (GND) connections between engine and chassis must be OK.
- Ignition switched off.

Test sequence






- Measure resistance between terminals of the respective valve for camshaft adjustment.
Specified value: 10 to 18 ohms

If specified value is not obtained:
- Replace the valve for camshaft adjustment.
- Erase DTC memory of Engine Control Module (ECM). [1][2]Reading and Clearing Diagnostic Trouble Codes
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If specified value is obtained:
- Connect test box to control module wiring harness. connect test box for wiring test.






- Check wire between test box socket 115 + 2-pin connector terminal 2 for open circuit according to wiring diagram.
Wire resistance: max: 1.5 ohms

- Check wires for short circuit to B+ and Ground (GND).
Specified value: Infinite ohms

- Check wire between 2-pin connector terminal 1 and the Fuel Pump (FP) Relay -J17- for open circuit according to wiring diagram.
Wire resistance: max: 1.5 ohms

If resistances and wires are OK:
- Replace Motronic Engine Control Module (ECM) -J220-.