J27 - Check HO2S Circuit For Short to Power.

Heated Oxygen Sensor Connector View:

- Key "OFF".

- Front Heated Oxygen Sensor (HO2S) disconnected.

- Disconnect HO2S heater relay.

- Measure resistance between the HO2S signal pin and VPWR pin at the HO2S vehicle harness connector.

- Is resistance greater than 10,000 Ohms?

Yes -- Replace Powertrain Control Module (PCM). Reconnect all components. Rerun Quick Test. Quick Test Appendix (Detailed Testing Instructions)

No -- Service short circuit. Reconnect all components. Clear keep alive memory. Clearing Keep Alive Memory (KAM) and Relearn Procedure Rerun Quick Test. Quick Test Appendix (Detailed Testing Instructions)