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-.
^ 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 On-Board Diagnostics (OBD) Output Diagnostic Test Mode (DTM) to activate intake manifold change-over valve.
^ LED must blink when intake manifold change-over valve is activated.

If LED does not blink or lights up continuously:
- Connect VAG 1598/19 test box to ECM wiring harness.
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 B 4.

If LED does not blink:
- Check wiring for continuity between intake manifold change-over valve connector terminal 2 and test box socket B 4.
^ 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 4 of ECM connector B.

If there is no wiring break or short circuit:
- Replace ECM.