Diagnosis Procedure

GAS SENSOR


Diagnosis Procedure

1.ADJUST GAS SENSOR SENSITIVITY
1. Turn ignition switch ON.
2. Adjust the gas sensor sensitivity. Refer to Gas Sensor Sensitivity Adjustment Function.
Are the symptoms solved?
YES - INSPECTION END
NO - GO TO 2.
2.CHECK POWER SUPPLY FOR GAS SENSOR
1. Turn ignition switch OFF.
2. Disconnect gas sensor connector.
3. Turn ignition switch ON.
4. Check voltage between gas sensor harness connector and ground.





Is the inspection result normal?
YES - GO TO 3.
NO - Check power supply circuit and 10A fuse (No. 3, located in the fuse block). Refer to Fuse Block - Junction Box (J/B).
- If fuse is OK, check harness for open circuit. Repair or replace if necessary.
- If fuse is NG, check harness for short circuit and replace fuse.
3.CHECK GROUND CIRCUIT FOR GAS SENSOR
1. Turn ignition switch OFF.
2. Check continuity between gas sensor harness connector and ground.





Is the inspection result normal?
YES - GO TO 4.
NO - Repair harness or connector.
4.CHECK GAS SENSOR SIGNAL
1. Reconnect gas sensor connector.
2. Turn ignition switch ON.
3. Check signal between gas sensor harness connector and ground using an oscilloscope.






NOTE:
The signal is different by measurement environment of a vehicle.
Is the inspection result normal?
YES - GO TO 5.
NO - Replace gas sensor.
5.CHECK CIRCUIT CONTINUITY BETWEEN UNIFIED METER AND A/C AMP. AND GAS SENSOR
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between unified meter and A/C amp. harness connector and gas sensor harness connector.





Is the inspection result normal?
YES - Replace unified meter and A/C amp.
NO - Repair harnesses or connectors.