J25 - Check Left/Front Heated Oxygen Sensor or Short to Power

Heated Oxygen Sensor Connector View:

NOTE: Due to the internal circuitry of the Powertrain Control Module (PCM), a left/front Heated Oxygen Sensor (HO2S) signal short to power could produce a Diagnostic Trouble Code (DTC) 542 or 543.

- Key "OFF".

- Disconnect left or front HO2S sensor.

- Measure resistance between HO2S signal pin and KEY POWER pin at the HO2S sensor connector.

- Is resistance greater than 10,000 ohms?

Yes -- Go to J26. J26 - Check HO2S Circuit For Short to Power

No -- Replace HO2S. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

Clear Keep Alive Memory. Clearing Keep Alive Memory (KAM) and Relearn Procedure