Signal Circuit Inspection
- Ignition "OFF".
- Refer to "HEATED OXYGEN SENSOR (HO2S) " and disconnect Upstream O2 Sensor connector.
- Ignition "ON"
- Measure voltage between Pin No. 3 (V_IP) terminal of Upstream O2 Sensor harness connector and chassis ground.
- Measure voltage between Pin No. 2 (V_N) terminal of Upstream O2 Sensor harness connector and chassis ground.
- Measure voltage between Pin No. 1 (V_G) terminal of Upstream O2 Sensor harness connector and chassis ground.
- Measure voltage between Pin No. 6 (V_RC) terminal of Upstream O2 Sensor harness connector and chassis ground.
Specification: Pin No. 3 (V_IP): 2.6V/Pin No. 2 (V_N): 2.1V/Pin No. 1 (V_G): 2.1V/Pin No. 6 (V_G): 2.6V
- Re-connect Upstream O2 Sensor connector.
- Ignition "OFF".
- Connect VMI to GDS and set up an oscilloscope as follow (2-channel);
Channel A (+): Pin No. 6 (V_RC) terminal of Upstream O2 Sensor.
Channel A (-): Pin No. 1 (V_G) terminal of Upstream O2 Sensor.
Channel B (+): Pin No. 3 (V_IP) terminal of Upstream O2 Sensor.
Channel B (-): Pin No. 2 (V_N) terminal of Upstream O2 Sensor.
- Ignition "ON" & Engine "ON".
- Testing Condition: Engine Idle.
Specification: Refer to Figure below
- Is the measured value within specification?
YES
- Go to "COMPONENT INSPECTION " procedure.
NO
- Repair open or short in signal circuit between Upstream O2 Sensor and PCM and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.