Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
- Ignition OFF, disconnect the harness connector at the appropriate HO2S.
- Ignition ON, test for B+ between the ignition voltage circuit and ground.
- HO2S 1 terminal 3
- HO2S 2 terminal E
- If less than the specified range, repair the ignition voltage circuit for a short to ground, or an open/high resistance.
- Test for 4.6-5 volts between the heater control circuit and ground.
- HO2S 1 terminal 4
- HO2S 2 terminal D
- If less than the specified range, test the heater control circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the heater control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Connect a test lamp between the heater control circuit and B+. Engine idling, the test lamp should illuminate, or flash.
- HO2S 1 terminal 4
- HO2S 2 terminal D
- If the test lamp does not illuminate, or flash, replace the ECM.
- If all circuits test normal, replace the appropriate HO2S.