Variable Valve Timing Solenoid: Testing and Inspection
Solenoid valve for camshaft adjustment, checking
Special tools and equipment:
^ VAG 1526 A Multimeter
^ VAG 1527 B Voltage tester
^ VAG 1594 A Connector test kit
^ VAG 1598/31 Test box
^ VAS 5051 Vehicle diagnosis, testing and information system with VAS 5051/1 Adapter
Requirement
^ VAS5051 tester connected and vehicle On Board Diagnostic (OBD) -01 Engine electronics- selected.
Valves for camshaft adjustment (intake), activating
- Initiate output Diagnostic Test Mode (DTM) and activate valve for camshaft adjustment bank 1:
Display on VAS5051:
A - Actuator test is waiting Advancing by switching required
5 - Bank 1, camshaft adjustment go to -N205-
- Click on _ button
Display on VAS5051:
A - Actuator test is running Advancing by switching allowed
^ This valve is activated for approximately 1 minute (clicks), unless _ button is pressed first to switch to the next actuator.
- Click on _ button
Display on VAS5051:
A - Actuator test is waiting Advancing by switching required
6 - Bank 2, camshaft adjustment go to -N208-
- Click on _ button
Display on VAS5051:
A - Actuator test is running Advancing by switching allowed
^ This valve is activated for approximately 1 minute (clicks), unless _ button is pressed first to switch to the next actuator.
- End function 03 - output Diagnostic Test Mode (DTM) by pressing _ button.
If one of the valves is not being activated (does not click).
- Switch ignition off.
- Perform an electrical test for valves for camshaft adjustment.
Valves for camshaft adjustment (exhaust), activating
- Initiate output Diagnostic Test Mode (DTM) and activate valve for camshaft adjustment (exhaust) bank 1:
Display on VAS5051:
A - Actuator test is waiting Advancing by switching required
7 - Bank 1, valve for camshaft adjustment (exhaust)
- Click on _ button
Display on VAS5051:
A - Actuator test is running Advancing by switching allowed
^ This valve is activated for approximately 1 minute (clicks), unless _ button is pressed first to switch to the next actuator.
- Click on _ button
Display on VAS5051:
A - Actuator test is waiting Advancing by switching required
8 - Bank 2, valve for camshaft adjustment (exhaust)
- Click on _ button
Display on VAS5051:
A - Actuator test is running Advancing by switching allowed
^ This valve is activated for approximately 1 minute (clicks), unless _ button is pressed first to switch to the next actuator.
- End function 03 - output Diagnostic Test Mode (DTM) by pressing _ button.
If one of the valves is not being activated (does not click).
- Switch ignition off.
- Perform an electrical test for valves for camshaft adjustment.
Electrical test of solenoid valve for camshaft adjustment
Cylinder bank 2 (left):
- Remove cover -1- in engine compartment (left side).
- Remove coolant reservoir (arrow)
- Remove line from Engine Coolant Level (ECL) warning switch -F66- and lay coolant reservoir to side.
Note: Coolant hoses 1 to 3 remain connected.
Cylinder bank 1 (right)
- Remove cover -1- in engine compartment (right side).
- Remove bolts (arrows).
- Detach Evaporative Emission (EVAP) canister purge regulator valve -N80- -1- at air guide.
- Remove air guide -2-.
- Remove air filter housing (arrows).
Continuation for both cylinder banks
- Disconnect harness connector (arrow) from connector adapter.
Note: Illustration depicts cylinder bank 2 (left).
Checking internal resistance
Valve for camshaft adjustment (intake)
- Connect multimeter between terminals 1 and 2 for resistance measurement.
^ Specification: 7.4 to 8.2 ohms
Valve for camshaft adjustment (exhaust)
- Connect multimeter between terminal 2 and 3 for resistance measurement.
^ Specification: 12.8 to 14.2 ohms
All
If specified value is not obtained:
- Replace valve.
If specified value is obtained:
Checking voltage supply
Requirement
^ ^ Fuse for valves for camshaft adjustment OK.
- Connect VAG1527B voltage tester as follows:
- Switch ignition on.
^ LED must light up
If LED does not light up:
- Check wire connection from terminal 2 of connector via fuse to Motronic Engine Control Module (ECM) power supply relay J271- for open circuit:
If LED lights up:
Checking activation
- Connect VAG1527B voltage tester as follows:
- Initiate output Diagnostic Test Mode (DTM) and activate valve for camshaft adjustment.
^ LED must blink
If LED does not blink or if it remains constantly lit:
- Connect VAG1598/31 test box to harness connectors of wiring harness (do not connect ECM). Connect Ground (GND) clip at test box (not visible in illustration) to Ground (GND).
- Check following wire connections for open circuit and short circuit to Ground (GND) and B+:
- Repair short circuit to Ground (GND) connection or open circuit if necessary.
If wire connection is OK:
- Replace Engine Control Module (ECM).
If no malfunctions are detected:
- Replace mechanical camshaft adjuster.