Chrysler Concorde 1993, Service Manual, Page: 185 / 820

(2) Main Relay. If the relay fails to make the
ground circuit connection or is an intermittent
ground. The (CAB) will turn on the Amber Anti-Lock
Warning Light.
Additionally, any condition which results in inter-
ruption of power to the (CAB) or (HCU) assembly
may cause the Amber Anti-Lock Warning Lamp to
turn on intermittently.
ABS BRAKE SYSTEM DIAGNOSTIC FEATURES
SYSTEM INITIALIZATION
System initialization starts when the ignition
switch is turned to the run position. At this point the
(CAB) performs a complete self check of all electrical
components in the Anti-Lock and Traction Control
systems. Momentarily the build, decay and isolation
valves are cycled. If the driver has his foot on the
brake pedal, they may feel the test through brake
pedal pulsations. This is a normal condition.
DYNAMIC TEST
Between 5 - 10 mph the pump/motor is momen-
tarily turned on.
If any component exhibits a fault during system
initialization or dynamic check, the (CAB) will illu-
minate the Anti-Lock warning lamp and Traction
Control Function Lamp. At this time both systems
are disabled.
DIAGNOSTIC MODE
To enter diagnostic mode, vehicle must be below 10
MPH. If vehicle speed is not below 10 MPH a no re-
sponse message is displayed by the DRB II scan tool.
The following are characteristics of the diagnostic
mode.
The amber Anti-Lock warning lamp and brake
warning lamp flash. If a hard fault, such as an Inlet
or Outlet Valve fault or Main Relay Power Circuit
failure fault is present. The warning lamps illumi-
nate without blinking and no diagnostic operations
are available until the fault condition is cleared.
Anti-Lock and Traction control operation are dis-
abled.
The valves in the valve body cannot be actuated
when vehicle speed is above 5 MPH. If valve actua-
tion is attempted above 5 MPH a vehicle in motion
message is displayed by the DRBII scan tool.
CONTROLLER ANTI-LOCK BRAKE (CAB)
Fault codes are kept in a Non-Volatile memory un-
til either erased by the technician using the DRB II
scan tool or automatically after 50 ignition cycles
(key cycles). The only fault that will not be erased af-
ter 50 (KEY CYCLES) is the (CAB) fault. A (CAB)
fault can only be erased by the technician using the
DRB II scan tool. More than one fault can be stored
at a time. The number of key cycles since the most
recent fault was stored is also displayed. Most func-
tions of the (CAB) and ABS system can be accessed
by the technician for testing and diagnostic purposes
by using the DRB II.
LATCHING VERSUS NON-LATCHING ABS
FAULTS
Some faults detected by the (CAB) are latching; the
fault is latched and (ABS) is disabled until the igni-
tion switch is reset. Thus ABS is disabled even if the
original fault has disappeared. Other faults are non-
latching; any warning lights that are turned on, are
only turned on as long as the fault condition exists.
As soon as the condition goes away, the Anti-Lock
Warning Light is turned off. Although a fault code
will be set in most cases.
TEVES MARK IV ELECTRONIC SYSTEMS
DIAGNOSTICS
The Teves Mark IV Anti-Lock Brake System Diag-
nostics, beyond the basic mechanical diagnostics, sys-
tems and components covered earlier in this section.
Are accomplished by the use of the DRB II scan tool.
See testing procedures outlined in the Teves Mark IV
Anti-Lock Brakes Diagnostics Manual for 1993 M.Y.
vehicles.
Please refer to the above mentioned manual for
any further electronic diagnostics and service proce-
dures that are required on the Teves Mark IV Anti-
Lock Brake System.
ON-CAR ABS BRAKE SYSTEM SERVICE
GENERAL SERVICE PRECAUTIONS
The following are general cautions which should be
observed when servicing the Anti-Lock brake system
and/or other vehicle systems. Failure to observe
these precautions may result in Anti-Lock Brake
System component damage.
If welding work is to be performed on the vehicle,
using an electric arc welder, the (CAB) connector
should be disconnected during the welding operation.
The (CAB) connector should never be connected or
disconnected with the ignition switch in the ON po-
sition.
Many components of the Anti-Lock Brake System
are not serviceable and must be replaced as an as-
sembly. Do not disassemble any component which is
not designed to be serviced.
ANTI-LOCK BRAKE SYSTEM 5 - 91