H26 - Check HO2S For Short to Ignition Run Circuit

- Key "OFF".

- Heated Oxygen Sensor (HO2S) disconnected.

- Measure resistance between KEY PWR circuit and HO2S SIG circuit at the connector (refer to schematic). H - Test Schematic

- Is resistance greater than 10,000 ohms?

Yes -- For Diagnostic Trouble Codes (DTC) 137, 173 and 177: Go to H27. H27 - Attempt to Generate DTC 136, 172, or 176

For DTCs 171, 174, 175, 178: Go to H30. H30 - HO2S Check

No -- Replace HO2S. Drive vehicle 5 miles/55 mph. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)