Chrysler Concorde 1993, Руководство по обслуживанию, Страница: 184 / 820

dicate reduced braking ability. The following
procedure should be used to test drive an ABS
complaint vehicle.
Before test driving a brake complaint vehicle, note
whether the Red or Amber Brake Warning Lamp is
turned on. If it is the Red Brake Warning Lamp, refer
to the standard brake, Control Valves Section in the
brake group of this manual. If the Amber Anti-Lock
Warning light was/is on, read record and erase the
fault. While the Amber ABS Warning Lamp is on the
ABS system is not functional. When the Amber Anti-
Lock Warning Lamp is on only the Anti-Lock function
of the brake system if affected. The standard brake
system and the ability to stop the car is not be affected
if only the Amber Anti-Lock Warning Lamp is on.
(1) Turn the key to the off position and then back to
the on position. Note whether the Amber ABS Warning
Lamp continues to stay on. If it does refer to the 1993
M.Y. Teves Mark IV Anti-Lock Brakes Diagnostic
Manual for the required test procedures.
(2) If the Amber ABS Warning Lamp goes out, shift
into gear and drive the car to a speed of 10 mph to
complete the ABS start up cycle. If at this time the
Amber ABS Warning Lamp goes on refer to the 1993
M.Y. Teves Mark IV Anti-Lock Brakes Diagnostic
Manual.
(3) If the Amber ABS Warning Lamp remains OUT,
drive the vehicle a short distance. During this test
drive be sure that the vehicle achieves at least 25 mph.
Brake to at least one complete stop and again acceler-
ate to 25 mph.
(4) If a functional problem with the A.B.S. system is
determined while test driving a vehicle. Refer to the
1993 M.Y. Teves Mark IV Anti-Lock Brakes Diagnos-
tics Manual for required test procedures and proper
use of the DRB II scan tool.
ABS BRAKE SYSTEM ON VEHICLE SERVICE
The following are general precautions which
should be observed when servicing and diagnos-
ing the ABS system and/or other vehicle systems.
Failure to observe these precautions may result
in ABS system damage.
(1) If welding work is to be performed on a vehicle
using an arc welder, the (CAB) should be disconnected
before the welding operation begins.
(2) The (CAB) connector should never be connected
or disconnected with the ignition in the on position.
(3) Some components of the ABS system are not
serviced separately and must be serviced as complete
assemblies. Do not disassemble any component which
is designated as non-serviceable.
CAUTION: Brake fluid will damage painted surfaces.
If brake fluid is spilled on any painted surfaces, wash
off with water immediately.
WHEEL SPEED SENSOR CABLES
Proper installation of the Wheel Speed Sensor Ca-
bles is critical to continued system operation. Be sure
that cables are installed, routed and clipped properly.
Failure to install speed sensor cables as shown in the
on car service section of this manual. May result in
contact with moving parts or over extension of ca-
bles, resulting in component failure and an open cir-
cuit.
MECHANICAL DIAGNOSTICS AND SERVICE
PROCEDURES
SPECIAL SERVICE TOOL
Some diagnostic procedures in this section require
the use of the DRB II scan tool. Refer to the DRB II
scan tool operators manual for its proper operational
information.
INTERMITTENT FAULTS
As with virtually any electronic system, intermit-
tent faults in the ABS system may be difficult to ac-
curately diagnose.
Most intermittent faults are caused by faulty elec-
trical connections or wiring. When an intermittent
fault is encountered, check suspect circuits for:
(1) Poor mating of connector halves or terminals
not fully seated in the connector body.
(2) Improperly formed or damaged terminals. All
connector terminals in a suspect circuit should be
carefully reformed to increase contact tension.
(3) Poor terminal to wire connection. This requires
removing the terminal from the connector body to in-
spect.
(4) Pin presence in the connector assembly
If a visual check does not find the cause of the
problem, operate the car in an attempt to duplicate
the condition and record the Fault code.
Most failures of the ABS system will disable Anti-
Lock function for the entire ignition cycle even if the
fault clears before key-off. There are some failure
conditions, however, which will allow ABS operation
to resume during the ignition cycle in which a fail-
ure occurred. If the failure conditions are no longer
present. The following conditions may result in inter-
mittent illumination of the Amber Anti-Lock Warn-
ing Lamp. All other failures will cause the lamp to
remain on until the ignition switch is turned off. Cir-
cuits involving these inputs to the (CAB) should be
investigated if a complaint of intermittent warning
system operation is encountered.
(1) Low system voltage. If Low System Voltage (9
volts or less) is detected by the (CAB), the (CAB) will
turn on the Amber Anti-Lock Warning Lamp until
normal system voltage is achieved. Once normal volt-
age is seen at the (CAB), normal operation resumes.
5 - 90 ANTI-LOCK BRAKE SYSTEM