Dodge ZB 2005 Service Manual page 240

ZB
BODY CONTROL MODULE (Continued)
(4) Place ignition in the RUN position (this exits
Battery save mode and places the BCM in the nor-
mal powered state).
REMOVAL
(1) Open deck lid.
(2) Remove four bolts to battery compartment
cover and remove cover.
(3) Disconnect and isolate the battery negative
cable.
(4) Wait two minutes for the airbag system reserve
capacitor to discharge before beginning any airbag
system or instrument panel component service.
(5) Disconnect the five Body Control Module
(BCM) electrical connectors.
(6) Remove the four retaining nuts to the BCM.
(7) Remove the BCM from the vehicle.
INSTALLATION
(1) Install the BCM in the vehicle.
(2) Install the four retaining nuts to the BCM.
(3) Connect the five Body Control Module (BCM)
electrical connectors.
(4) Connect the battery negative cable.
(5) Install battery compartment cover and install
four retaining bolts.
(6) Close deck lid.
(7) Verify vehicle and system operation.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The controller antilock brake (CAB) is a micropro-
cessor-based device which monitors the ABS system
during normal braking and controls it when the vehi-
cle is in an ABS stop. The CAB is mounted to the
HCU (hydraulic control unit) as part of the ICU
(integrated control unit) (Fig. 1). The CAB uses a
24-way wiring connector on the vehicle wiring har-
ness. The power source for the CAB is through the
ignition switch in the RUN or ON position.
OPERATION
The primary functions of the controller antilock
brake (CAB) are to:
• monitor the antilock brake system for proper
operation.
• detect wheel locking or wheel slipping tenden-
cies by monitoring the speed of all four wheels of the
vehicle.
• control fluid modulation to the wheel brakes
while the system is in ABS mode.
• store diagnostic information.
ELECTRONIC CONTROL MODULES 8E - 3
Fig. 1 Integrated Control Unit (Typical)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
• provide communication to the DRBIII scan tool
while in diagnostic mode.
The CAB constantly monitors the antilock brake
system for proper operation. If the CAB detects a
fault, it will turn on the amber ABS warning indica-
tor lamp and disable the antilock braking system.
The normal base braking system will remain opera-
tional.
The CAB continuously monitors the speed of each
wheel through the signals generated by the wheel
speed sensors to determine if any wheel is beginning
to lock. When a wheel locking tendency is detected,
the CAB commands the CAB command coils to actu-
ate. The CAB command coils then open and close the
valves in the HCU that modulate brake fluid pres-
sure in some or all of the hydraulic circuits. The CAB
continues to control pressure in individual hydraulic
circuits until a locking tendency is no longer present.
The CAB contains a self-diagnostic program that
monitors the antilock brake system for system faults.
When a fault is detected, the amber ABS warning
lamp is turned on and the fault diagnostic trouble
code (DTC) is then stored in a diagnostic program
memory. These DTC's will remain in the CAB mem-
ory even after the ignition has been turned off. The
DTC's can be read and cleared from the CAB mem-
ory by a technician using the DRBIII scan tool. If not
cleared with a DRBIII scan tool, the fault occurrence
and DTC will be automatically cleared from the CAB
memory after the identical fault has not been seen
during the next 3,500 miles of vehicle operation.