Diagnostic Procedure
- CHECK GROUND CONNECTIONS
- Turn ignition switch OFF.
- Loosen and retighten ground three screws on the body.
Refer to "GROUND INSPECTION ".
Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
OK: GO TO 2.
NG: Repair or replace ground connections.
- RETIGHTEN HEATED OXYGEN SENSOR 1
Loosen and retighten heated oxygen sensor 1.
Tightening torque: 50 N.m (5.1 kg-m, 37 ft-lb)
GO TO 3.
- CHECK HO2S1 GROUND CIRCUIT FOR OPEN AND SHORT
- Disconnect heated oxygen sensor 1 harness connector.
- Disconnect ECM harness connector.
- Check harness continuity between HO2S1 terminal 3 and ECM terminal 78.
Refer to WIRING DIAGRAM .
Continuity should exist.
- Also check harness for short to ground and 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 HO2S1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Check harness continuity between HO2S1 terminal 2 and ECM terminal 35.
Refer to WIRING DIAGRAM .
Continuity should exist.
- Check harness continuity between ECM terminal 35 or HO2S1 terminal 2 and ground.
Refer to WIRING DIAGRAM .
Continuity should not exist.
- Also check harness for short to power and short to ground.
OK or NG
OK: GO TO 5.
NG: Repair open circuit or short to ground or short to power in harness or connectors.
- Check harness continuity between HO2S1 terminal 2 and ECM terminal 35.
- CHECK HO2S1 CONNECTOR FOR WATER
Check heated oxygen sensor 1 connectors for water.
Water should not exist.
OK or NG
OK: GO TO 6.
NG: Repair or replace harness or connectors.
- CHECK HEATED OXYGEN SENSOR 1
Refer to "COMPONENT INSPECTION ".
OK or NG
OK: GO TO 7.
NG: Replace heated oxygen sensor 1.
- CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".
INSPECTION END