Honda Accord 2008 Manual page 1480

07/11/02 09:34:17 61TA0000_190_0059
ABS Features
Anti-lock Control
Without ABS, when the brake pedal is pressed while driving, the wheels sometimes lock before the vehicle comes to a
stop. In such an event, the maneuverability of the vehicle is reduced if the front wheels are locked, and the stability of
the vehicle is reduced if the rear wheels are locked, creating an extremely unstable condition. With ABS, the system
precisely controls the slip rate of the wheels to ensure maximum grip force from the tires, and it thereby ensures
maneuverability and stability of the vehicle. The ABS calculates the slip rate of the wheels based on the four wheel
speeds, and then it controls the brake fluid pressure to reach the target slip rate.
Grip force of tire and road surface
＊０３
Main Control
The control unit detects the wheel speed based on the wheel speed sensor signals it receives, then it calculates the
vehicle speed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration
based on the wheel speeds.
The control unit calculates the slip rate of each wheel, and transmits the control signal to the modulator unit solenoid
valve when the slip rate is high.
The hydraulic control has three modes: Pressure intensifying, pressure reducing, and pressure retaining.
＊０４
COEFFICIENT OF
FRICTION
RIGHT-REAR
Detect
WHEEL SPEED
Wheel Speed
SENSOR
LEFT-REAR
Detect
WHEEL SPEED
Wheel Speed
SENSOR
RIGHT-FRONT
Detect
WHEEL SPEED
Wheel Speed
SENSOR
LEFT-FRONT
Detect
WHEEL SPEED
Wheel Speed
SENSOR
TARGET SLIP RATE
ROTATIONAL
DIRECTION
RADIAL
DIRECTION
OF THE
ROTATIONAL
DIRECTION
SLIP RATE
Detect Reference
Vehicle Speed Slip Rate
RIGHT-REAR
Detect ABS
Slip Rate Control
LEFT-REAR
Select Low Detect ABS
Speed Wheel Slip Rate Control
RIGHT-FRONT
Detect ABS
Slip Rate
Control
LEFT-FRONT
Detect ABS
Slip Rate Control
CONTROL UNIT
Drive RIGHT-REAR
Solenoid
SOLENOID
Drive LEFT-REAR
Solenoid SOLENOID
RIGHT-FRONT
Drive
Solenoid SOLENOID
Drive LEFT-FRONT
Solenoid SOLENOID
(cont'd)
19-59