Inspection Procedure

INSPECTION PROCEDURE

1. Disconnect the engine control module connector, check voltage between terminals HTL2, HTR2 of engine control module connector and body ground.





- Connect the Check Harness A.
- Disconnect engine control module connector.
- Turn ignition switch on.
- Measure voltage between terminals HTL2, HTR2 of engine control module connector and body ground.

Voltage: 9 - 14 volts

- If OK proceed to step 3.
- If not OK proceed to step 2.
2. Check sub heated oxygen sensor heater.





- Disconnect sub heated oxygen sensor connector.
- Measure resistance between terminals 1 and 2 of sub heated oxygen sensor connector.

Resistance: 5.1 - 6.3 ohms 2O°C (68°F)

- If OK check and repair harness or connector between main relay and sub heated oxygen sensor, sub heated oxygen sensor and engine control module.
- If not OK replace sub heated oxygen sensor.
3. Check voltage between terminals HTL2, HTR2 of engine control module connector and body ground.





- Connect engine control module connector.
- Warm up engine to normal operating temperature.
- Measure voltage between terminals HTL2, HTR2 of engine control module connector and body ground when engine is idling and racing at 4,000 rpm.

Idling voltage: 0.0 volts
4,000 rpm voltage: 9 - 14 volts

- In the 4,000 rpm racing check, continue engine racing at 4,000 rpm for approximately 20 seconds or more.

- If OK replace sub heated oxygen sensor.
- If not OK check and replace engine control module.