VC Output Circuit [12/2023 - ]: Description
WARNING: This page is about a different car, the 2024 Lexus TX 550h+. However, it is still accessible from the selected car via links, so may be relevant.
The ECM constantly generates 5 V power source voltage from the auxiliary battery voltages supplied to the +B, +B2 (BATT) terminal to operate the microprocessor. The ECM also provides this power source voltage to the sensors through the VC output circuit.
When the VC circuit is shorted, the microprocessor in the ECM and sensors that are supplied power through the VC circuit are inactivated because the power is not supplied from the VC circuit. When the system is in this condition, it will not start.