Toyota Avalon (XX50) 2019-2022 Service & Repair Manual > Sfi System: ECM Power Source Circuit. EVAP System. Fail-safe Chart
ECM Power Source Circuit DESCRIPTION When the power switch is turned to on (IG), the auxiliary battery voltage is applied to IGSW of the ECM. When the transistor in the MREL circuit operates, current flows from the auxiliary battery to ground through the drive circuit of the EFI-MAIN NO. 1 relay, th ...