Testing solenoid valves for camshaft adjustment: Audi 2.8 (ACK, ALG)

ALG
Note:

Fitting locations of solenoid valves=>Pages
24-8
.

Special tools, testers and auxiliary items

Hand multimeter V.A.G 1526 or V.A.G 1526 A
Diode test lamp V.A.G 1527
Adapter set V.A.G 1594
Test box V.A.G 1598/22

Connect fault reader V.A.G 1551
=> Page
01-3
.
Switch ignition on.
Start final control diagnosis and select camshaft timing control => Page
01-79
.

Final control diagnosis
⇒
Camshaft timing control 1
Indicated on display:

When the camshaft timing control is activated the solenoid valves should click audibly.

If the valve does not click, switch off the ignition.

Unplug connector from the solenoid valve which is being tested.

Measure the resistance between the solenoid valve contacts using V.A.G 1526.
Specification: 10 ... 18ω

If the value does not match the specification, fit a new solenoid valve.

Testing voltage supply to camshaft adjustment valves

(-N205 and -N208)

Unplug connector on the solenoid valve which is being tested.

Connect diode test lamp V.A.G 1527 to contact 1 on connector and to engine earth using auxiliary leads from V.A.G 1594.
Operate starter for a few seconds. The engine can be allowed to start.

Specification: The diode test lamp should light up.

If the diode test lamp does not light up, carry out the following tests:

Test fuse for camshaft adjustment valve.
Test for open circuit in wiring between contact 1 of connector for camshaft adjustment valve and fuse.

=> Current flow diagrams, Electrical fault-finding and Fitting locations

Test fuel pump relay and activation
=> Page
24-46
.

Testing activation of camshaft timing control

Connect diode test lamp V.A.G 1527 to contact 1 (positive) and contact 2 on valve connector using test leads from auxiliary cable set V.A.G 1594.
Start final control diagnosis and select camshaft timing control => Page
01-79
.

Final control diagnosis
⇒
Camshaft timing control 1
Indicated on display:

When the camshaft timing control is activated the diode test lamp should start flashing.

If the diode test lamp does not flash or if it lights up continuously, connect test box V.A.G 1598/22 to wiring harness for engine control unit => Page
24-24
.

If the diode test lamp lights up continuously, test for short to earth in wiring from contact 2.

=> Current flow diagrams, Electrical fault-finding and Fitting locations

If the diode test lamp does not flash, test for open circuit or short to positive in wiring between contact 2 on connector and contact 55 on test box.

=> Current flow diagrams, Electrical fault-finding and Fitting locations

Rectify any short circuits to earth or open circuits if found.
If no short circuits or open circuits are found, fit a new engine control unit => Page
24-26
.
If the wiring connections are OK, fit a new mechanical camshaft adjuster

=> 6-cylinder engine (5-valve), Mechanics; Repair group 15; Cylinder head, valve gear; Removing and installing camshafts
6-cylinder engine (5-valve), Mechanics
Cylinder head, valve gear
Removing and installing camshafts