Main Heated Oxygen Sensor Testing

Main Sensor Inspection
1. Warm engine to normal operating temperature.



2. Connect a jumper wire between terminal TE1 and E1 of the data link connector (DLC1).
3. Connect digital volt-ohm meter (DVOM) between terminals VF1 and E1 of DLC1.
4. Perform the following test.

Oxygen Sensor Diagnostic Chart:

Main Sensor Heater Inspection

Note: The following test is only necessary if code 27 is present.

1. Disconnect sensor electrical connector.



2. Measure heater resistance across sensor terminals B+ and HT.

Resistance at 68°F (20°C): 11 - 16 Ohms

^ Replace sensor if not within specified range.