Honda CR-V 1997 Service Manual page 952

ABS Control
The ASS control unit detects the wheel speed based on the wheel sensor signal it received , then it calculates the vehicle
speed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration based on the
rate of deceleration.
The ASS control unit calc ulates the slip rate of each wheel, and it tran smits the control signal to th e modulator unit
solenoid valve when the slip fate is high.
The pressure reduction control has three modes: pressure reducing, pressure retaining, and pressure intensifying modes.
DETECT
WHEEL SPEED
DETECT
WHEEl SPEED
SELECT LOW
$PEEOWHEEL
REAR
DETECT
SLIP RATE
AIGHT-FRONT
DETECT
SLIP RATE
LEFT· FRONT
ABS
CONTROl
DETECT DETECT ABS DAIVE
WHEEL SPEED SLf'RATE CONTR SOLENOID
=~=
L: _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _
Self-diagnosis Function
The ASS control unit is equipped with a main CPU and a sub CPU, that check each other for problems.
The CPUs check th e circuit of the system .
When the CPUs detect failure, they shift to the " system down mode" or the " control inhibition mode".
MODE ABS INDICATOR LIGHT
MAIN SOLENOID
CPU Restart condition
RELAY VALVE
SYSTEM
ON
No Drive
Igni tion
1
OFF - ON (II)
DOWN operation inhibition
Operation* '
switch
CONTROL
ON
No
Drive
Operation Automatic
INHIBITION
operation inhibition
DTC
Memory
Memory
*1: Except CPU failure
The self-diagnosis ca n be classified into these four categories:
CD:
Initial diagnosis
@:
Exce pt ABS control
@:
During ABS co ntrol
@:
During warning
On-board Diagnosis Function
The ABS system can be diagnosed with the Honda PGM Tester.
The ALB Checker can not be used with this system. For air bleeding, and checking wheel sensor signals, use the Honda
PGM Tester. See the Honda PGM Tester user's manuals for specific operating instructions.
(cont'd)
19-29