Circuit/System Testing
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, open the hood to disable the Auto-Stop function.
- Ignition ON, verify the scan tool hood position parameter displays Open.
- If the hood position does not display Open, refer to DTC P254F .
- Ignition OFF, disconnect the harness connector of the appropriate HO2S.
- Ignition ON, test for 2.5-3.5 V between the reference voltage circuit terminal 6 and ground.
- If greater than the specified range, test the reference voltage circuit for a short to the heater control circuit. If the circuit tests normal, replace the ECM.
- Test for 2-3 V between the low reference circuit terminal 2 and ground.
- If greater than the specified range, test the low reference circuit for a short to the heater control circuit. If the circuit tests normal, replace the ECM.
- Test for 2-3 V between the input pump circuit terminal 1 and ground.
- If greater than the specified range, test the input pump circuit and pump current circuit for a short to the heater control circuit. If the circuit tests normal, replace the ECM.
- If all circuits/connections test normal, replace the appropriate HO2S.