A6 Sedan V6-2.8L (AHA) (1998)
Variable Valve Timing Actuator: Testing and Inspection
Valves For Camshaft Adjustment, Checking
Required special tools and test equipment
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VAG 1551 Scan Tool (ST) with VAG 1551/3 adapter cable
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Multimeter US 1119 (Fluke 83 or equivalent)
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VW 1594 connector test kit
Function
The camshaft adjustment is dependent on engine speed and load. The electrical solenoid valves for camshaft adjustment (-N205- and -N208-) are
switched to apply oil pressure to the mechanical camshaft adjusters, which adjusts the camshaft timing.
Checking
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Connect VAG 1551/1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (with engine running at
idle) Refer To On-Board Diagnostics II. See: Powertrain Management/Computers and Control Systems/Testing and Inspection
Indicated on display
Rapid data transfer
HELP
Select function XX
-
Press buttons -0- and -3- to select "Output Diagnostic Test Mode" function 03.
Indicated on display
Rapid data transfer
Q
03 - Output Diagnostic Test Mode
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Press -Q- button to confirm input.
Indicated on display
Output Diagnostic Test Mode
->
Camshaft adjustment 1
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Check using output DTM and activate camshaft adjustment.
Valves 1 and 2 for camshaft adjustment, -N205- and -N208-, must click audibly.
If the valves do not click:
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Check as described in test procedures that follow.
Checking solenoid valves for camshaft adjustment electrically
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Disconnect harness connector from valve.
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Using multimeter with auxiliary wires from VAG 1594, measure resistance across terminals on valve.
Specified value: 10 - 18 ohms