Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the HO2S 1.
- Connect a 3A fused jumper wire between the high signal circuit terminal 1 and low signal circuit terminal 5.
- Test for greater than 1 volt between the pump current circuit terminal 2 and ground
- If less than the specified range, test the pump current circuit for an open. If the circuit tests normal, replace the ECM.
- If all circuits test normal, replace the HO2S 1.