1) Disconnect the connectors from VDCCM.
2) Start the engine.
3) Run the engine at idle.
4) Measure the voltage between VDCCM connector and chassis ground.
Connector & terminal
(B310) No. 28 (+) — Chassis ground (−):
Is the voltage 10 — 15 V?
Repair the power supply circuit of the VDCCM.