Oxygen Sensor

The oxygen sensor is heated to control operating temperature of the sensor. The heating element receives voltage from terminal No. 87 of the fuel pump relay and is heated as long as the fuel pump operates.

The oxygen sensor system uses a malfunction indicator, which is located on the instrument panel. The malfunction indicator light will come on if a malfunction is present in the oxygen sensor circuit. The oxygen sensor malfunction indicator light receives voltage from the CIS-E control unit.

There are 2 versions of the malfunction light:

• Version 1: Lights up briefly when starting the engine.
• Version 2: Lights up as soon as the ignition is switched on and goes out when the engine is started. If an oxygen sensor failure is present, the malfunction indicator lights up after about 5 minutes of engine operation.