H53 - Check Continuity of HO2S and HO2S Ground Circuits

- Key Off.

- Breakout box installed, PCM disconnected.

- Disconnect suspect HO2S from harness. Inspect both ends or connector for damaged or pushed out pins, moisture, corrosion, loose pins etc. and service.

- Measure the resistance between HO2S Signal Test Pin at the breakout box and the HO2S harness connector. Use the Pin assignment below and record the reading.

- Measure resistance between SIG RTN test pin at the breakout box and HO2S SIG RTN harness connector. Record readings.

- HO2S-11 SIG = Test Pin 60
- HO2S-21 SIG = Test Pin 87
- HO2S SIG RTN = Test Pin 91

- Is the resistance reading less than 5.0 ohms?

YES -- Go to H54. H54 - Check HO2S Circuit Wiring Harness For Short to Ground

NO -- SERVICE open circuit. REMOVE breakout box. RECONNECT PCM and HO2S. DRIVE 5 miles/55 mph. Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes