Yamaha YP250A 1999 Supplementary Service Manual page 16

4. Electronic control unit
Relation of the input signal and output signal is shown in the diagram.
The circuit receives the signals from wheel sensors, processes them according to the programs in the mi-
crocomputer and outputs the control signal to the hydraulic unit and ABS warning light.
Power
Front brake
switch signal
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
Main CPU
(Main microcomputer)
Brake
light circuit
Starter
switch
circuit
Digital
conversion
circuit
Sub CPU
(Sub microcomputer)
ABS OUTLINE
Electronic control unit (ECU)
Motor monitor
Memory
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
Front wheel speed
output circuit
8
GEN
INFO
Solenoid valve
Motor
Hydraulic
unit (HU)
Solenoid
Motor relay Fail-safe
relay
ABS warning light
Checker
Speedometer