ECU Power Source Circuit [12/2017 - 10/2023]: Description

Power is supplied to the B terminal of the sub-battery module assembly from the battery power source.

The B terminal supplies power to the sub battery ECU, which uses it for sub battery charging and discharging control, condition judgment, DTC output and freeze frame data output.

When the LUG-IG1 NO. 1 relay is turned on while the engine switch is on (IG), power is supplied to the IG terminal of the sub-battery module.