Intake Manifold Change-Over Valve, Checking

Intake Manifold Change-Over Valve, Checking

Special tools, testers and auxiliary items required

• (VAG1526A)

• (VAG1527B)

• (VAG1594A)

• (VAG1598/31)

• (VAS5051) with (VAS5051/1)

Test sequence

- Remove front engine cover (arrows).





- Disconnect connectors to intake manifold change-over valve (N156) - 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; checking. Refer to => [ Fuel Pump Relay and Activation, Checking ] Fuel Pump Relay and Activation, Checking.

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

- Connect voltage tester (VAG1527B) as follows:









- 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 (VAG1527B) between terminals 1 and 2.





- Initiate final control diagnosis and activate intake manifold change-over valve. Refer to => [ Output Diagnostic Test Mode ] Output Diagnostic Test Mode.

• LED should flash.

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

- Connect test box (VAG1598/31) to wiring harness for engine control module; engine control module must not be connected. Refer to => [ Wiring and Component Check with Test Box VAG 1598/31 ] Wiring and Component Check With Test Box VAG 1598/31.

- Check for open circuit and short to positive or Ground in following wiring connections:





- Repair any open/short circuit as necessary.

If no wiring malfunction is detected:

- Replace engine control module:

• With anti-theft housing. Refer to => [ Engine Control Module with Metal Anti-Theft Housing ] Engine Control Module With Metal Anti-Theft Housing

• Without anti-theft housing. Refer to => [ Engine Control Module without Metal Anti-Theft Housing ] Engine Control Module Without Metal Anti-Theft Housing