Diagnostic Procedure
- CHECK GROUND CONNECTIONS
- Turn ignition switch OFF.
- Loosen and retighten three ground screws on the body.
Refer to Ground Inspection .
OK or NG
- OK: GO TO 2.
- NG: Repair or replace ground connections.
- CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
- Disconnect heated oxygen sensor 2 harness connector.
- Disconnect ECM harness connector.
- Check harness continuity between ECM terminal 78 and HO2S2 terminal 4. Refer to
Wiring Diagram .
- Continuity should exist.
- Also check harness for short to ground and short to power.
OK or NG
- OK: GO TO 3.
- NG: Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram .
- Continuity should exist.
- Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram .
- Continuity should not exist.
- Also check harness for short to power.
OK or NG
- OK: GO TO 4.
- NG: Repair open circuit or short to ground or short to power in harness or connectors.
- Check harness continuity between ECM terminal and HO2S2 terminal as follows.
- CHECK HO2S2 CONNECTOR FOR WATER
Check connectors for water.
- Water should not exist.
OK or NG
- OK: GO TO 5.
- NG: Repair or replace harness or connectors.
- CHECK HEATED OXYGEN SENSOR 2
Refer to Component Inspection .
OK or NG
- OK: GO TO 6.
- NG: Replace malfunctioning heated oxygen sensor 2.
- CHECK INTERMITTENT INCIDENT
Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .
- INSPECTION END