Audi Workshop Service and Repair Manuals

• ‒ Switch on ignition.
• ‒ Perform final control diagnosis and actuate camshaft timing control .

Solenoid valve must be heard to click distinctly on actuation of camshaft timing control.

Perform the following checks if reading does not match specification.

Electrical check on camshaft adjustment solenoid valve

• ‒ Unplug connector from camshaft adjustment solenoid valve.
• ‒ → Measure resistance with portable multimeter V.A.G 1526 between solenoid valve contacts.

• Specification: 10 ... 18 ω

If reading does not match specification:

• ‒ Replace camshaft adjustment solenoid valve.

Checking power supply for camshaft adjustment solenoid valve

• ‒ Unplug connector at solenoid valve.
• ‒ → Connect diode test lamp V.A.G 1527 with leads from adapter set V.A.G. 1594 to socket 1 of connector (positive) and engine earth.
• ‒ Operate starter for several seconds. Engine may also start.

Diode test lamp must light.

Perform the following checks if diode test lamp does not light.

• ‒ Check fuse for camshaft adjustment solenoid valve.

=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder

If fuse is OK:

• ‒ → Check for continuity in wiring from socket 1 of connector for camshaft adjustment solenoid valve via fuse to fuel pump relay.

=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder

Checking actuation of camshaft adjustment valve

• ‒ Unplug connector at solenoid valve.
• ‒ → Connect diode test lamp V.A.G 1527 with leads from adapter set V.A.G 1594 to sockets 1 (positive) and 2 of connector at solenoid valve.
• ‒ Perform final control diagnosis and actuate camshaft timing control => Page 01-46.

Diode test lamp must flash during actuation of camshaft timing control.

If diode test lamp does not flash or if it is permanently lit:

• ‒ Connect test box V.A.G 1598/31 to engine control unit wiring harness. Actual engine control unit is not to be connected.

If diode test lamp is permanently lit:

• ‒ → Check for short to earth in wiring from socket 2 of connector for camshaft adjustment solenoid valve.

If diode test lamp does not flash:

• ‒ → Check for continuity and short to positive in wiring from socket 2 of connector for camshaft adjustment solenoid valve to socket 115 of test box.

• Resistance: max. 1.5 ohms

=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder

• ‒ If necessary, eliminate short circuit/open circuit in wiring.

If there is neither an open circuit in the wiring nor a short circuit, replace engine control unit => Page 24-16.

• ‒ If no faults were found in any of the preceding checks, replace mechanical camshaft adjuster.

=> 4-cyl. Engine, Mechanics; Repair Group 15; Cylinder Head, Valve Gear; Removing and installing camshafts and camshaft adjuster