Oxygen Sensor: Description and Operation

When the Automatic Shut Down (ASD) relay contacts close, they connect circuits A14 and A142. Circuit A142 splices to supply voltage to the heated oxygen sensor.

Circuit K41 delivers the signal from the heated oxygen sensor to the Powertrain Control Module (PCM). Circuit K41 connects to cavity 41 of the PCM.

The PCM provides a ground for the heated oxygen sensor signal (circuit K41) through circuit K4. Circuit K4 connects to cavity 4 of the PCM connector.

Circuit Z1 provides a ground for the heater circuit in the sensor.

Circuit Z1 terminates at the rear of the engine.