A6 Quattro Sedan V6-2.8L (AHA) (1998)
Variable Valve Timing Solenoid: Testing and Inspection
Camshaft Adjustment System, Checking
Camshaft adjustment system, 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.
Camshaft adjustment function, 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 (engine running at
idle).Refer to "Scan tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1551/VAG 1552 Scan Tool" See: Powertrain
Management/Computers and Control Systems/Testing and Inspection
Indicated on display
Rapid data transfer
HELP
Select function XX
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Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.
Indicated on display
Read Measuring Value block
HELP
Input display group number XXX
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Press buttons -0-, -9- and -0- to input display group number 90 (090), and press -Q- button to confirm input.
Indicated on display (1-4 = display groups)
Read Measuring Value Block 90
->
1 2 3 4
NOTE:
Display field 2 indicates whether the engine control module has activated the camshaft adjustment.
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"CS-ctrl OFF:" camshaft adjustment is not active.
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"CS-ctrl ON:" camshaft adjustment is active (this can only be attained during a test drive)
Display fields 3 and 4 show whether the camshaft adjustment did actually occur (via input from sensors):
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Normal Position: -3.0 ° to 6.0 ° KW.
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Shifted position: 16.0 ° KW to 25.0 ° KW.
NOTE: If, during the test drive, display field 3 and/or 4 displays a value between 6.0 ° KW and 16.0 ° KW, the electrical valves for camshaft
adjustment have switched the oil pressure to the respective mechanical camshaft adjuster, but it cannot attain the correct end position (e.g. due to
sluggishness).
WARNING!
A second technician is required to operate the VAG 1551 scan tool during the road test. Safety precautions.
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Accelerate from rest in 1st gear (manual) or with selector lever in "2" position (automatic).
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Check specified values for camshaft adjustment (display fields 2-4)