Intake Manifold Change-Over Valve -N156- Checking

Intake Manifold Change-over Valve -N156- Checking

Special Tools and Equipment







- VAG1526A
- VAG1527B
- VAG1594A
- VAG1598/31
- VAS5051 with VAG5051/1
or
- VAG1551 with VAG1551/3B

Test requirement:
- Output Diagnostic Test Mode (DTM) performed
- Fuse for intake manifold change-over valve is OK
- Fuel Pump (FP) OK, checking. Testing and Inspection

Checking internal resistance
- Disconnect connector from Intake Manifold Change-Over Valve -N156-.







- Connect multimeter at valve for resistance measurement.
- Specification: 25 to 35 Ohms
- Replace Intake Manifold Change-Over Valve -N156- if specified value is not obtained.

Checking voltage supply
- Disconnect connector from Intake Manifold Change-Over Valve -N156-.







- Connect VAG1527B voltage tester as follows:







- Operate starter briefly.
- LED must light up.

If LED does not light up:
- Check wire connection from terminal 1 to Fuel Pump (FP) relay via fuse for open circuit.

Checking activation







- Connect VAG1527B voltage tester between terminals 1 and 2
- Initiate output Diagnostic Test Mode and activate the intake manifold change-over valve. Output Diagnostic Test Mode (DTM) (Function 03)
- LED must blink.

If LED does not blink or if it remains constantly lit:
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Connecting VAG 1598/31 Test Box







- Check the following wire connection for open circuit and short circuit to Ground (GND) and B+:







- Repair open circuit or short circuit if necessary.

If wire connection is OK:
- Replace Engine Control Module (ECM).