32
Front brake
switch signal
Power
Rear brake
switch signal
Stop lamp
signal
Starter
switch
signal
Starter switch
Front
wheel sensor
Rear
wheel sensor
Voltage
regulator
Front brake
switch
circuit
Rear brake
switch
circuit
Brake
light circuit
Starter
switch
circuit
Digital
conversion
circuit
Main CPU
(Main microcomputer)
Sub CPU
(Sub microcomputer)
Memory
Electronic control unit (ECU)
Motor monitor
circuit
Solenoid
motor
Solenoid drive
circuit
Fail-safe relay
drive circuit
Motor relay
drive circuit
Warning light
drive circuit
Operation mode
switching circuit
Fault code
output circuit
Solenoid valve
Motor
Hydraulic
unit (HU)
Solenoid
Motor relay
Fail-safe
relay
ABS warning light
Checker
Speedometer
Front wheel speed
output circuit
ANTI-LOCK BRAKE SYSTEM (ABS)
CHAS
Electronic control unit (ECU)
Electronic control unit 1 controls the ABS and is
installed inside the taillight unit. To protect from
water invasion, it is enveloped by a cover 2 .
As shown in the block diagram below, the ECU
takes in the wheel sensor signals from front and
rear wheels and also receives the signals from
various monitor circuits. Two of main and sub mi-
crocomputers are installed in the ECU providing
mutual monitoring.