CHECK CONNECTOR WIRING HARNESS.

1) Connect the disconnected power supply CM connectors.

2) Using a tester, measure the voltage between the power supply CM terminal and chassis ground when the ignition switch is turned from OFF to ACC ON.

Connector & terminal

(B420) No. 11 (+) — Chassis ground (−):

QUESTION

Did the voltage change from less than 1 V to +B−2 V or more?

Yes No

System is normal. It is possible that a temporary poor contact occurs.

Replace the power supply CM.