CHECK ECM GROUND HARNESS.

Measure the voltage between ECM and chassis ground.

Connector & terminal

(B134) No. 5 (+) — Chassis ground (−):

(B137) No. 1 (+) — Chassis ground (−):

(B137) No. 2 (+) — Chassis ground (−):

(B137) No. 3 (+) — Chassis ground (−):

(B137) No. 7 (+) — Chassis ground (−):

QUESTION

Is the voltage less than 1 V?

Yes No

Repair the poor contact of the ECM connector.

Repair the following item.

Open circuit in ground circuit

Further tightening of the engine ground terminal

Poor contact of coupling connector