4B Oxygen Sensor Circuit

1. With oxygen sensor electrical connector disconnected, place ignition switch in the Off position.
2. Disconnect black electrical connector from logic module.
3. Connect an ohmmeter between logic module black electrical connector terminal No. 18 and oxygen sensor electrical connector terminal.
4. If ohmmeter indicates continuity, replace logic module.
CAUTION: Before replacing the logic module make sure the terminal in cavity No. 18 is not crushed so that it cannot touch the logic module pin.
5. If continuity is not indicated, check wiring between terminal No. 18 of logic module black electrical connector and oxygen sensor for an open circuit.