Variable Induction Control Valve: Testing and Inspection

Electrical check

- Disconnect harness connector on intake manifold change-over valve -N156-.

Intake Manifold Change-over Valve Test:

- Measure valve resistance.
^ Specified value: 25-35 (ohms)

If specified value is not obtained:

- Replace intake manifold change-over valve.

Checking battery positive voltage (B+) supply

- Disconnect harness connector on intake manifold change-over valve.

2-Pin Connector:

- Connect US 1115 LED tester or equivalent between harness connector terminal 1 (positive) and Ground (GND) using adapter from VW 1594 connector test kit.
- Use On-Board Diagnostics (OBD) output diagnostic test mode (DTM) to activate fuel pump relay -J17-. Testing and Inspection
^ LED must light up

If LED does not light up:

- Check HO2S circuit breaker -S73- (brown holder in electronics box, passenger side footwell).
- Check wiring for continuity between valve harness connector terminal 1 and circuit breaker using wiring diagram.
^ Specified reading: 0.5 (ohms)
- Check fuel pump relay and activation.

Checking intake manifold change-over valve activation

- Connect US 1115 LED tester or equivalent across terminals 1 and 2 of intake manifold change-over valve connector using adapter from VW 1594 connector test kit.
- Use output Diagnostic Test Mode (DTM) to activate intake manifold change-over valve. Testing and Inspection
^ LED must blink when intake manifold change-over valve is activated.

If LED does not blink or lights up continuously:

- Connect VAG 1598 test box to ECM wiring harness for using adapter harness VAG 1598/11. Connecting VAG 1598/31 Test Box
^ Adapter harness for ECM is not connected.

If LED lights up continuously:

- Check wiring for short circuit to GND between intake manifold change-over valve connector terminal 2 and test box socket 3.

If LED does not blink:

- Check wiring for continuity between intake manifold change-over valve connector terminal 2 and test box socket 3.
^ Specified reading: maximum 1.0 (ohm)
- If necessary, eliminate short circuit to GND or wiring break between intake manifold change-over valve connector terminal 2 and terminal 3 of ECM connector C.

If there is no wiring break or short circuit:

- Replace ECM.