Oxygen Sensor Relay: Testing and Inspection

INSPECTION




1. REMOVE RELAY BOX COVER
2. REMOVE A/F SENSOR HEATER RELAY (Marking: A/F HTR)




3. INSPECT A/F SENSOR HEATER RELAY CONTINUITY
a. Using an Ohmmeter, check that there is continuity between terminals 1 and 2.

If there is no continuity, replace the relay.

b. Check that there is no continuity between terminals 3 and 5.

If there is continuity, replace the relay.




4. INSPECT A/F SENSOR HEATER RELAY OPERATION
a. Apply battery voltage across terminals 1 and 2.
b. Using an Ohmmeter, check that there is continuity between terminals 3 and 5.

If there is no continuity, replace the relay.

5. REINSTALL A/F SENSOR HEATER RELAY
6. REINSTALL RELAY BOX COVER