H12 - Check For HO2S Signal Short to HO2S Heater Circuit

- Key Off.

- Suspect HO2S sensor disconnected.

- Scan Tool connected.

- Key On, Engine Off.

- View HO2S (PID) corresponding to DTCs received.

NOTE: (HO2S displayed as 02S on Scan Tool.)

- Is the HO2S voltage less than 0.2 volts?

YES -- REPLACE HO2S. RECONNECT all components. Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes

NO -- REPLACE PCM. RECONNECT all components. Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes