Heated Oxygen Sensor Heater Control System

Heated Oxygen Sensor Heater (Front)
1. Remove the ECM.




2. Connect the Special Service Tools to the ECM.
3. Turn the ignition switch to ON.
4. Measure the voltage at ECM terminal 4E and 41 by using a voltmeter

Specification: Below 1.0 V

5. Position the vehicle on a chassis roller and shift the selector lever to D.
6. Increase the engine speed over 4,000 rpm and measure the voltage at ECM terminals 4E and 4I by using a voltmeter.

Specification: Battery positive voltage

7. If not as specified, inspect following.
- ECM terminal 3E voltage (Mass air flow sensor)
- ECM terminal 4AL, 4AH voltage (Crankshaft position sensor)
- Heated oxygen sensor.