Chrysler RAM TRUCK 2500 1994 Service Manual page 184

• REAR WHEEL ANTILOCK BRAKE (RWAL) SYSTEM 5 - 25
R E A R W H E E L ANTILOCK B R A K E (RWAL) SYSTEM
INDEX
page
Antilock Component Serviceability 29
Clearing A Fault Code 28
Combination Valve Operation 27
Control Module Removal/Installation 30
Diagnostic Fault Flash Codes 28
Fault Code Capacity 28
Fault Code Identification 28
Fault Condition Causes 29
General Information 25
page
Rear Speed Sensor Rear Harness Removal/
Installation 32
Rear Speed Sensor Removal/Installation 31
Rear Wheel Antilock System Diagnosis 28
Rear Wheel Antilock System Operation 27
RWAL System Brake Bleeding 32
RWAL System Components 25
RWAL Valve/Combination Installation 29
RWAL Valve/Combination Valve Removal . 29
GENERAL INFORMATION
A rear wheel antilock (RWAL) brake system is
standard equipment on all BR models (Fig. 1). The
system is controlled by a separate electronic control
module.
SPEED
SENSOR
ANTILOCK
VALVE
EXCITER
RING
J93GS45
Fig. 1 Rear Wheel Antilock (RWAL) Brake System
The RWAL system retards rear wheel lockup dur­
ing periods of high wheel slip and deceleration. Re­
tarding lockup is accomplished by modulating fluid
pressure to the rear brake units.
Rear brake fluid apply pressure is modulated ac­
cording to wheel speed, degree of wheel slip and rate
of deceleration. A sensor i n the rear axle housing con­
verts differential rotating speed into electronic sig­
nals. The signals are transmitted to the electronic
control module for processing. The control module de­
termines rate of deceleration and wheel slip from
these signals.
RWAL SYSTEM COMPONENTS
RWAL system components include:
• electronic control module
• rear brake antilock (RWAL) valve
• speed sensor and exiter ring
• antilock warning lamp
A standard master cylinder and vacuum power
brake booster are used for all applications. A l l of the
RWAL system hydraulic components are located on
the driver side of the engine compartment (Fig. 2).
MASTER
CYUNDER
ASSEMBLY
RWAL
VALVE
J9405-76
Fig. 2 RWAL System Hydraulic Component Location
Electronic Control Module
The electronic module controls operation of the so­
lenoids i n the rear brake antilock valve. The module
is separate from other electrical circuits in the vehi­
cle and operates independently.