Camshaft Timing Control, Checking

Camshaft Timing Control, Checking

Function of camshaft timing control

The timing control of the intake camshaft is dependent on the engine load and engine speed. The exhaust camshafts are not timed.

The electrical solenoid valves for camshaft timing control (Valves for camshaft adjustment) switch oil pressure to the camshaft adjuster (mechanical timing control device).

The mechanical camshaft adjusters then time the intake camshafts of both banks of cylinders toward "advanced", i.e. the intake valves open earlier.

Checking camshaft timing control function

- Connect vehicle diagnostic, testing and information system VAS 5051 or V.A.G 1551 Scan Tool and select engine electronics control unit 1 with "Address word" 01. For this purpose, engine must be running at idle speed.

Indicated on display
Rapid data transfer HELP
Select function XX


- Press keys 0 and 4 for function "Basic Setting" and confirm entry by pressing Q key.

Indicated on display


Basic setting
Enter display group number XXX


- Press keys 0, 9 and 4 for "display group number 94" and confirm entry with Q key.

Indicated on display


Basic setting 94 ->
1 2 3 4

Display Group 94:

- Check specified value for camshaft timing control.
- Increase speed approx. 2000 rpm until "CS adj.ON" appears in display zone 2.

Display Group 94:

- Keep speed until "Syst. OK" appears in display zones 3 and 4.

Display Group 94:

If specified value in display zones 3 and 4 is not achieved:
- Check solenoid valves for camshaft timing control.