CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from rear oxygen sensor.

3) Turn the ignition switch to ON.

4) Measure the voltage between rear oxygen sensor connector and chassis ground.

Connector & terminal

(E22) No. 4 (+) — Chassis ground (−):

QUESTION

Is the voltage 0.2 — 0.5 V?

Yes No

Replace the rear oxygen sensor.

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit of harness between the ECM and rear oxygen sensor

• Poor contact in ECM connector

• Poor contact of coupling connector