CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from ECM.

3) Measure the resistance between ECM and front oxygen (A/F) sensor connector.

Connector & terminal

Euro 4 model

(B134) No. 1 — (E23) No. 4:
(B134) No. 2 — (E23) No. 4:
(B134) No. 9 — (E23) No. 4:
(B134) No. 10 — (E23) No. 4:

Euro 5 model

(B134) No. 1 — (E23) No. 4:
(B134) No. 2 — (E23) No. 4:

QUESTION

Is the resistance less than 1 Ω?

Yes No

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit in harness between ECM and front oxygen (A/F) sensor connector

• Poor contact of coupling connector