Component Tests and General Diagnostics

NOTE: Do not conduct this test any longer than needed to detect a change in CO (carbon monoxide) reading on analyzer.


1. Be sure engine is at normal operating temperature.
2. Connect exhaust gas analyzer to sampling points in exhaust pipe.

Oxygen Sensor Plug:

3. Disconnect oxygen sensor plug.

Fig. 49 Oxygen Sensor Connector Plug:

4. Using a jumper wire, momentarily connect terminal 1 of control unit side of plug, to ground.
5. CO reading should increase.
6. If there is no change, check connection to LH control unit and unit coding. If needed, replace control unit.