100S Quattro Wagon (Canada) V6-2.8L (AAH) (1992)
Intake Manifold Change-Over Valve: Testing and Inspection
Electrical check
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Disconnect harness connector on intake manifold change-over valve -N156-.
Intake Manifold Change-over Valve Test
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Measure valve resistance.
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Specified value: 25-35 (ohms)
If specified value is not obtained:
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Replace intake manifold change-over valve.
Checking battery positive voltage (B+) supply
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Disconnect harness connector on intake manifold change-over valve.
2-Pin Connector
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Connect US 1115 LED tester or equivalent between harness connector terminal 1 (positive) and Ground (GND) using adapter from VW 1594
connector test kit.
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Use On-Board Diagnostics (OBD) output diagnostic test mode (DTM) to activate fuel pump relay -J17-. See: Computers and Control
Systems/Testing and Inspection
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LED must light up
If LED does not light up:
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Check HO2S circuit breaker -S73- (brown holder in electronics box, passenger side footwell).
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Check wiring for continuity between valve harness connector terminal 1 and circuit breaker using wiring diagram.
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Specified reading: 0.5 (ohms)
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Check fuel pump relay and activation.
Checking intake manifold change-over valve activation
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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.
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Use output Diagnostic Test Mode (DTM) to activate intake manifold change-over valve. See: Computers and Control Systems/Testing and
Inspection
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LED must blink when intake manifold change-over valve is activated.
If LED does not blink or lights up continuously: