Ground Circuit Inspection
- Ignition "OFF".
- Disconnect battery (-) cable.
- Refer to "HEATED OXYGEN SENSOR (HO2S) " and disconnect Upstream O2 Sensor connector.
- Measure resistance between Pin No. 2 (Ground) terminal of upstream O2 sensor harness connector and chassis ground.
Specification: Approx. below 1 Ω
- Is the measured value within specification?
YES
- Go to "SIGNAL CIRCUIT INSPECTION " procedure.
NO
- Repair open or short in ground circuit between Upstream O2 Sensor and ECM and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.