Cabriolet V6-2.8L (AFC) (1995)
Heated Oxygen Sensor: Testing and Inspection
Electrical Testing
SENSOR ELECTRICAL TESTS:
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Disconnect harness connector for Heated Oxygen Sensor (HO2S) signal wire.
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Connect multimeter(Fluke 83 or equivalent) between oxygen sensor signal wire and GND.
^
Specified value: infinite ohms (no continuity).
If NO:
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Replace HO2S.
If YES:
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Switch multimeter to 0-2 volts measuring range and connect between signal wire connector (to ECM) and GND.
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Switch ignition ON.
^
Specified value: 400 +/- 50 mV.
If YES:
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Check wiring to ECM.
WIRING CHECKS:
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Switch ignition OFF.
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Connect VAG 1598 test box to ECM wiring harness using VAG 1598/11 adapter harness.
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Adapter harness for ECM is not connected.
Engine Control Module (ECM) Connectors
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Check for continuity between Heated Oxygen Sensor (HO2S) 1 G39 signal wire and test box socket 50.
^
Specified value: maximum 1 ohm.
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Check for continuity between H02S 2 G108 signal wire and test box socket 48.
^
Specified value: maximum 1 ohm.
If specified values are not obtained:
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Repair open or short circuit in wiring connection between connector in engine compartment and ECM connector A terminal 50 and/or 48,
according to wiring diagrams.
If there is no malfunction in wiring connection:
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Replace ECM.