CHECK OUTPUT SIGNAL OF ECM.

1) Disconnect the connector from the rear oxygen sensor.

2) Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B134) No. 29 (+) — Chassis ground (−):

QUESTION

Is the voltage less than 1 V?

Yes No

Replace the ECM.

Repair the battery short circuit of harness between ECM and rear oxygen sensor connector. After repair, replace the ECM.