Dodge 2000 DURANGO Service Manual page 187

DN
DESCRIPTION AND OPERATION (Continued)
RWAL COMPONENT LOCATION
DESCRIPTION
COMPONENT
RWAL CONTROLLER
HYDRAULIC CONTROL UNIT/
RWAL VALVE
REAR WHEEL SPEED SENSOR
EXCITER RING
RED BRAKE WARNING LAMP
AMBER ABS WARNING LAMP
BRAKE WARNING LAMP DIODE
ISOLATION AND DUMP VALVE
FUSE
ISOLATION AND DUMP
SOLENOID/VALVES
CONTROLLER REAR WHEEL ANTILOCK
BRAKES
DESCRIPTION
The Controller Antilock Brakes (CAB) is a micro-
processor which handles testing, monitoring and con-
trolling the ABS brake system operation (Fig. 1). The
CAB functions are:
• Perform self-test diagnostics.
• Monitor the RWAL brake system for proper oper-
ation.
• Control the RWAL valve solenoids.
NOTE: If the CAB needs to be replaced, the rear
axle type and tire revolutions per mile must be pro-
gramed into the new CAB. For axle type refer to
Group 3 Differential and Driveline. For tire revolu-
tions per mile refer to Group 22 Tire and Wheels. To
program the CAB refer to the Chassis Diagnostic
Manual.
LOCATION
Driver side inner fender on a
bracket.
Driver side inner fender on a
bracket.
Top of the rear axle housing.
Ring gear inside the differential
housing.
Instrument cluster.
Instrument cluster.
Instrument panel harness near the
parking brake switch.
Inside the CAB.
Inside the HCU/RWAL valve.
1 – RWAL CAB
BRAKES
FUNCTION
Tests, monitors and controls the
rear brake system.
Modulates hydraulic pressure to
rear brakes during an RWAL stop.
Sends an AC voltage sinewave to
the CAB whose frequency is
proportional to vehicle speed.
Used to pull the magnetic field
across the wheel speed sensor's
windings.
Indicator for park brake
engagement, hydraulic brake
malfunction, or RWAL malfunction.
Indicator of an RWAL malfunction.
Isolates the park brake switch circuit
from the CAB for proper red brake
warning lamp operation.
Fail-safe device for unwanted
control of the isolation and dump
solenoid/valves
Used to modulation hydraulic
pressure to the rear brakes during
an RWAL stop.
Fig. 1 RWAL CAB
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