H17 - Check Continuity of HO2S Signal and HO2S Ground
- Key "OFF".
- Breakout box installed, Powertrain Control Module (PCM) disconnected.
- Disconnect suspect Heated Oxygen Sensor (HO2S) from vehicle harness. Inspect both ends of connector for damaged or pushed out pins, moisture, corrosion, loose wires, etc. Service as necessary.
- Measure resistance between HO2S circuit test pin at the breakout box and HO2S circuit at the vehicle harness connector.
- Measure resistance between SIG RTN test pin at the breakout box and HO2S SIG RTN at the vehicle harness connector.
- Where applicable measure resistance between HO2S GND and SIG RTN at the breakout box.
- Is each resistance less than 5.0 ohms?
Yes -- Go to H18. H18 - Check HO2S Circuit For Short to Ground
No -- Service open circuit. Remove breakout box. Reconnect PCM, HO2S, and any other components that have been disconnected. Drive vehicle 5 miles/55 mph. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)