H24 - Check Resistance of HO2S Signal Circuit

- Key Off.

- PCM disconnected, breakout box installed.

- Measure the resistance between HO2S Signal Test Pin at the breakout box and the HO2S harness connector.

- Measure the resistance between Signal RTN test pin at the breakout box and the HO2S harness connector.
- HO2S-11 = SIG. Pin 60
- HO2S-21 = SIG. Pin 87
- HO2S-11 = SIG. RTN Pin 91
- HO2S-21 = SIG. RTN Pin 91

- Is the resistance less than 5.0 ohms?

YES -- Go to H25. H25 - Check For Short In HO2S Circuit

NO -- Resistance is high. SERVICE open circuit. REMOVE breakout box. RECONNECT all components. COMPLETE a HO2S monitor drive cycle.