QA6 - Isolate Short to Harness or HO2S

- Breakout box installed, Powertrain Control Module (PCM) disconnected.

- Disconnect right/rear Heated Oxygen Sensor (HO2S).

- Key "ON", engine "OFF".

- Measure voltage between HO2S signal test pin 29 or 44 and test pin 40 or 60 at the breakout box. Refer to Pinpoint Test H schematic. H - Test Schematic

- Is voltage greater than 2.0 volts?

Yes -- Service HO2S signal circuit for shorts to power. Remove breakout box. Reconnect all components. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Replace right/rear HO2S. Remove breakout box. Reconnect all components. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)