Signal Circuit Inspection
- Ignition "OFF".
- Refer to "HEATED OXYGEN SENSOR (HO2S) " and disconnect Upstream O2 Sensor connector.
- Ignition "ON".
- Measure voltage between Pin No. 1 (Signal) terminal of upstream O2 Sensor harness connector and chassis ground.
Specification: Approx. 0.45V
- Is measured value within specification?
YES
- Go to "COMPONENT INSPECTION " procedure.
NO
- Repair open or short in signal circuit between Upstream O2 Sensor and ECM and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.