Oxygen Sensor Relay: Testing and Inspection
A/F SENSOR HEATER RELAYINSPECTION
1. REMOVE A/F SENSOR HEATER RELAY
2. INSPECT A/F SENSOR HEATER RELAY CONTINUITY
a. Using an ohmmeter, check that there is no continuity between terminals 1 and 2.
If there is continuity, replace the relay.
b. Check that there is continuity between terminals 3 and 5.
If there is no continuity, replace the relay.
3. INSPECT A/F SENSOR HEATER RELAY OPERATION
a. Apply battery voltage across terminals 3 and 5.
b. Using an ohmmeter, check that there is continuity between terminals 1 and 2.
If there is no continuity, replace the relay.
4. REINSTALL A/F SENSOR HEATER RELAY