Signal Circuit Inspection
- Ignition "OFF".
- Refer to EXHAUST MANIFOLD 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 illustration
- Is 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.