Circuit Description
The M-ASTC-ECU and transfer-ECU control the buzzer by turning the power transistor in the ECU on and off. The M-ASTC-ECU outputs the buzzer signal when an abnormality occurs in the Hydraulic Brake Booster (HBB). Also, the M-ASTC-ECU turns on the brake warning light. The transfer-ECU outputs buzzer signal when an abnormality occurs in active TRAC 4WD system. See Fig 1 .