CHECK POWER SUPPLY TO FRONT OXYGEN (A/F) SENSOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from front oxygen (A/F) sensor.

3) Turn the ignition switch to ON.

4) Measure the voltage between front oxygen (A/F) sensor connector and engine ground.

Connector & terminal

(B379) No. 1 (+) — Engine ground (−):

QUESTION

Is the voltage 10 V or more?

Yes No

Repair the power supply line.

NOTE:

In this case, repair the following item:

• Open circuit in harness between A/F, oxygen sensor relay and front oxygen (A/F) sensor

• Poor contact of A/F, oxygen sensor relay connector