Circuit Description
The M-ASTC-ECU controls the buzzer by turning on and off power transistor in M-ASTC-ECU. The M-ASTC-ECU outputs buzzer signal when HBB malfunctions. Also, M-ASTC-ECU turns on brake warning light. See Fig 1 . The buzzer will sound under the following cases:
- When pump motor is locked (DTC 53 is set).
- When pump motor is energized abnormally for a long period (DTC 55 is set).
- When accumulator pressure is abnormally low (DTC 57 is set).
- When solenoid valve temperature in M-ASTC-ECU is abnormally high (DTC is not set).