Variable Induction Control Valve: Testing and Inspection

Intake Manifold Change-Over Valve -N156-, Checking







Special tools and equipment

- VAG 1526 A
- VAG 1527 B
- VAG 1594 A
- VAG 1598/31
- VAS 5051 with VAS 5051/1

Test sequence







- Remove front engine cover (arrows).







- Disconnect connectors to intake manifold change-over valve -N156- -pos. -1-.

Checking internal resistance







- Connect multimeter to injector to measure resistance.
- Specified value: 25 to 35 Ohms

If specified value is not obtained:

- Replace intake manifold change-over valve -N156-.

If specified value is obtained:

Checking power supply

Test requirements

- Fuse for intake manifold change-over valve OK.
- Fuel pump relay OK. Testing and Inspection

NOTE: Power supply of the intake manifold change-over valve is via the fuel pump relay.







- Connect voltage tester VAG 1527 B as follows:

Connector Measure to
terminal

1 Engine ground

- Operate starter briefly.
- LED should illuminate.

If the LED does not illuminate:

- Check wiring from terminal 1 on connector via fuse to fuel pump relay for an open circuit.
- Repair open circuit if necessary.

If LED lights up:

Checking actuation

- Connect voltage tester VAG 1527 B between terminals 1 and 2.
- Initiate final control diagnosis and activate intake manifold change-over valve. Basic Setting (Function 04)
- LED should flash.

If the LED lamp does not flash or if it illuminates continuously:

- Connect test box VAG 1598/31 to wiring harness for engine control module; engine control module must not be connected. Wiring and Component Testing Using VAG1598/31 Test Box
- Check for open circuit and short to positive or Ground in following wiring connections:

Connector Test box VAG 1598/31
terminal Socket
2 48

- Repair any open/short circuit as necessary.

If no wiring malfunction is detected:
- Replace engine control module.