Check Chart 1
Check Chart 1: ETACS Power-Supply And Ground Circuits:
1. ETACS POWER-SUPPLY AND GROUND CIRCUITS
Description of Operation
The battery supplies a stabilized 5V power supply to the ECU, via the constant-voltage circuit and terminal 51 (which is directly connected to the battery).
Check Chart 1: ECU Terminal No. 51:
ECU Terminal Voltage (Connection condition of the ECU connector).