H25 - Check For Short to Power

- Key "OFF".

- Inspect HO2S GND and HO2S circuit harness for chaffing, burns or other indications of short to power. Service as necessary.

- Disconnect Powertrain Control Module (PCM). Inspect for damaged, or pushed out pins, corrosion, loose wires etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Suspect HO2S disconnected.

- Measure resistance between HO2S circuit, and KEYPWR at the breakout box.

- Is the resistance greater than 10,000 ohms?

Yes -- Replace PCM. Remove breakout box. Reconnect HO2S. Drive vehicle 5 miles/55 mph. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Service short to power. Remove breakout box. Reconnect PCM. Drive vehicle 5 miles/55 mph. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)