Oxygen Sensor Relay: Testing and Inspection

3UR-FE ENGINE CONTROL SYSTEM: A/F SENSOR HEATER RELAY: ON-VEHICLE INSPECTION

1. REMOVE INTEGRATION RELAY (UNIT E)

(a) Remove the engine room relay block cover.

(b) Using a screwdriver, detach the 2 claws and remove the integration relay from the engine room relay block.





HINT
Tape the screwdriver tip before use.

(c) Disconnect the 3 connectors.

2. INSPECT INTEGRATION RELAY (A/F)

NOTICE:
* Some relays are built into the integration relay (unit E). The integration relay cannot be disassembled. If there is a malfunction in the circuit of the integration relay, replace the integration relay.
* The internal circuit of the integration relay is as shown in the illustration below. Inspect the integration relay using the following procedures.





(a) Measure the resistance of the A/F fuse.

(1) Measure the resistance according to the value(s) in the table below.

Standard resistance:





If the result is not as specified, replace the A/F fuse.

(b) Measure the resistance of the A/F sensor heater relay circuit.





(1) Measure the resistance according to the value(s) in the table below.

Standard resistance:





If the result is not as specified, replace the integration relay.

3. INSTALL INTEGRATION RELAY (UNIT E)

(a) Connect the 3 connectors.

(b) Install the integration relay to the engine room relay block.

(c) Install the engine room relay block cover.