A8L Quattro Sedan W12-6.0L (BSB) (2005)
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Variable Valve Timing Actuator: Testing and Inspection
Diagnostic Procedures
Camshaft Adjustment Valves, Checking
Function
The camshaft adjustment is load- and RPM dependent. The electrical valves for camshaft adjustment switch oil pressure onto camshaft adjusters
(mechanical adjustment mechanisms), which then adjust the camshafts.
Special tools, testers and auxiliary items required
‹› Hand multimeter (V.A.G 1526) or Multimeter (V.A.G 1715)
‹› Test adapter kit (V.A.G 1594)
‹› Wiring diagram
Test Conditions
‹› Motronic Engine Control Module (ECM) Power Supply Relay (J271) -position 4- must be OK, check:
‹› The Ground (GND) connections between engine and body must be OK.
‹› Ignition switched off.
‹› Fuses in right instrument panel fuse holder must be OK:
Right instrument panel fuse holder
Test Sequence
Cylinder bank 1
-
Disconnect corresponding 2-pin harness connector from respective valve for camshaft adjustment:
