52,500 Miles (84 000 km) or at 42 months
²Change engine oil.
²Flush and replace engine coolant if not done at
36 months.
60,000 Miles (96 000 km) or at 48 months
²Change engine oil.
²Replace engine oil filter.
²Replace air cleaner element.
²Check PCV valve and replace, if necessary.
*
²Inspect serpentine drive belt, replace if neces-
sary.
²Inspect tie rod ends and boot seals.
67,500 Miles (108 000 km) or at 54 months
²Change engine oil.
²Inspect brake linings.
75,000 Miles (120 000 km) or at 60 months
²Change engine oil.
²Replace engine oil filter.
²Inspect serpentine drive belt, replace if neces-
sary. This maintenance is not required if belt was
previously replaced.
²Flush and replace engine coolant if it has been
30,000 miles (48 000 km) or 24 months since last
change.
82,500 Miles (132 000 km) or at 66 months
²Change engine oil.
²Flush and replace engine coolant if it has been
30,000 miles (48 000 km) or 24 months since last
change.
90,000 Miles (144 000 km) or at 72 months
²Change engine oil.
²Replace engine oil filter.
²Replace air cleaner element.
²Check PCV valve and replace, if necessary.
Not required if previously changed. *
²Inspect serpentine drive belt, replace if neces-
sary. This maintenance is not required if belt was
previously replaced.
²Inspect tie rod ends and boot seals.
²Inspect brake linings.
97,500 Miles (156 000 km) or at 78 months
²Change engine oil.
100,000 Miles (160,000 km)
²Replace spark plugs on 3.3L and 3.8L
engines.
²Replace ignition cables on 3.3L and 3.8L
engines.
105,000 Miles (168 000 km) or at 84 months
²Change engine oil.
²Replace engine oil filter.
²Inspect serpentine drive belt, replace if neces-
sary. This maintenance is not required if belt was
previously replaced.
²Flush and replace engine coolant if it has been
30,000 miles (48 000 km) or 24 months since last
change.
112,500 Miles (180 000 km) or at 90 months
²Change engine oil.
²Inspect brake linings.
²Flush and replace engine coolant if it has been
30,000 miles (48 000 km) or 24 months since last
change.
120,000 Miles (192 000 km) or at 96 months
²Change engine oil.
²Replace engine oil filter.
²Replace automatic transmission fluid.
²Replace engine air cleaner element.
²Check and replace PCV valve, if necessary.
*
²Inspect serpentine drive belt. Not required if
replaced at 75,000, 90,000 or 105,000 miles.
²Inspect tie rod ends and boot seals.
* This maintenance is recommended by Chrysler to
the owner but is not required to maintain the war-
ranty on the PCV valve.
** If California vehicle, this maintenance is recom-
mended by Chrysler to the owner but is not required
to maintain the warranty of the timing belt.
SCHEDULE ± B
3,000 Miles (5 000 km)
²Change engine oil.
6,000 Miles (10 000 km)
²Change engine oil.
²Replace engine oil filter.
9,000 Miles (14 000 km)
²Change engine oil.
²Inspect brake linings.
12,000 Miles (19 000 km)
²Change engine oil.
²Replace engine oil filter.
15,000 Miles (24 000 km)
²Change engine oil.
²Inspect air cleaner element. Replace as
necessary.
0 - 4 LUBRICATION AND MAINTENANCENS
GENERAL INFORMATION (Continued)
²Replace spark plugs.
²Replace ignition cables.
²Inspect serpentine drive belt, replace if neces-
sary. This maintenance is not required if belt was
previously replaced.
²Drain and refill automatic transaxle fluid and
replace filter. Adjust band, if so equipped. (See note)
²Change AWD power transfer unit fluid.
78,000 Miles (125 000 km)
²Change engine oil.
²Replace engine oil filter.
81,000 Miles (130 000 km)
²Change engine oil.
²Inspect brake linings.
²Flush and replace engine coolant.
84,000 Miles (134 000 km)
²Change engine oil.
²Replace engine oil filter.
²Change AWD overrunning clutch and rear car-
rier fluid.
87,000 Miles (139 000 km)
²Change engine oil.
90,000 Miles (144 000 km)
²Change engine oil.
²Replace engine oil filter.
²Replace air cleaner element.
²Check PCV valve and replace if necessary.
Not required if previously changed. *
²Inspect serpentine drive belt, replace if neces-
sary. This maintenance is not required if belt was
previously replaced.
²Drain and refill automatic transmission fluid
and replace filter. Adjust bands, if so equipped. (See
note)
²Change AWD power transfer unit fluid.
²Inspect tie rod ends and boot seals.
²Inspect brake linings.
93,000 Miles (149 000 km)
²Change engine oil.
96,000 Miles (154 000 km)
²Change engine oil.
²Replace engine oil filter.
99,000 Miles (158 000 km)
²Change engine oil.
²Inspect brake linings.
102,000 Miles (163 000 km)
²Change engine oil.
²Replace engine oil filter.
105,000 Miles (168 000 km)
²Change engine oil.
²Inspect air cleaner element. Replace as
necessary.
²Inspect serpentine drive belt, replace if neces-
sary. This maintenance is not required if belt was
previously replaced.
²Drain and refill automatic transmission fluid
and filter. Adjust bands, if so equipped. (See note)
²Change AWD power transfer unit fluid.
²Change AWD overrunning clutch and rear car-
rier fluid.
108,000 Miles (173 000 km)
²Change engine oil.
²Replace engine oil filter.
²Inspect brake linings.
111,000 Miles (178 000 km)
²Change engine oil.
²Flush and replace engine coolant.
114,000 Miles (182 000 km)
²Change engine oil.
²Replace engine oil filter.
117,000 Miles (187 000 km)
²Change engine oil.
²Inspect brake linings.
120,000 Miles (192 000 km)
²Change engine oil.
²Replace engine oil filter.
²Replace air cleaner element.
²Inspect PCV valve. Replace as necessary. *
²Inspect serpentine drive belt. Not required if
replaced at 75,000, 90,000 or 105,000 miles.
²Drain and refill automatic transmission fluid
and replace filter. Adjust bands, if so equipped.
²Change AWD power transfer unit fluid.
²Inspect tie rod ends and boot seals.
* This maintenance is recommended by Chrysler to
the owner but is not required to maintain the war-
ranty on the PCV valve.
** If California vehicle, this maintenance is recom-
mended by Chrysler to the owner but is not required
to maintain the warranty of the timing belt.
NOTE: Operating vehicle more than 50% in heavy
traffic during hot weather, above 90ÉF (32ÉC), using
vehicle for police, taxi, limousine type operation or
trailer towing require the more frequent transaxle
service noted in Schedule ± B. Perform these ser-
vices if vehicle is usually operated under these con-
ditions.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
0 - 6 LUBRICATION AND MAINTENANCENS
GENERAL INFORMATION (Continued)
JUMP STARTING, HOISTING AND TOWING
INDEX
page page
SERVICE PROCEDURES
HOISTING RECOMMENDATIONS............ 9JUMP STARTING PROCEDURE.............. 7
TOWING RECOMMENDATIONS.............. 8
SERVICE PROCEDURES
JUMP STARTING PROCEDURE
WARNING: REVIEW ALL SAFETY PRECAUTIONS
AND WARNINGS IN GROUP 8A, BATTERY/START-
ING/CHARGING SYSTEMS DIAGNOSTICS. DO NOT
JUMP START A FROZEN BATTERY, PERSONAL
INJURY CAN RESULT. DO NOT JUMP START WHEN
MAINTENANCE FREE BATTERY INDICATOR DOT IS
YELLOW OR BRIGHT COLOR. DO NOT JUMP
START A VEHICLE WHEN THE BATTERY FLUID IS
BELOW THE TOP OF LEAD PLATES. DO NOT
ALLOW JUMPER CABLE CLAMPS TO TOUCH
EACH OTHER WHEN CONNECTED TO A BOOSTER
SOURCE. DO NOT USE OPEN FLAME NEAR BAT-
TERY. REMOVE METALLIC JEWELRY WORN ON
HANDS OR WRISTS TO AVOID INJURY BY ACCI-
DENTAL ARCING OF BATTERY CURRENT. WHEN
USING A HIGH OUTPUT BOOSTING DEVICE, DO
NOT ALLOW BATTERY VOLTAGE TO EXCEED 16
VOLTS. REFER TO INSTRUCTIONS PROVIDED
WITH DEVICE BEING USED.
CAUTION: When using another vehicle as a
booster, do not allow vehicles to touch. Electrical
systems can be damaged on either vehicle.
TO JUMP START A DISABLED VEHICLE:
(1) Raise hood on disabled vehicle and visually
inspect engine compartment for:
²Battery cable clamp condition, clean if necessary.
²Frozen battery.
²Yellow or bright color test indicator, if equipped.
²Low battery fluid level.
²Generator drive belt condition and tension.
²Fuel fumes or leakage, correct if necessary.
CAUTION: If the cause of starting problem on dis-
abled vehicle is severe, damage to booster vehicle
charging system can result.
(2) When using another vehicle as a booster
source, park the booster vehicle within cable reach.
Turn off all accessories, set the parking brake, placethe automatic transmission in PARK or the manual
transmission in NEUTRAL and turn the ignition
OFF.
(3) On disabled vehicle, place gear selector in park
or neutral and set park brake. Turn off all accesso-
ries.
(4) Connect jumper cables to booster battery. RED
clamp to positive terminal (+). BLACK clamp to neg-
ative terminal (-). DO NOT allow clamps at opposite
end of cables to touch, electrical arc will result.
Review all warnings in this procedure.
(5) On disabled vehicle, connect RED jumper cable
clamp to positive (+) terminal. Connect BLACK
jumper cable clamp to engine ground as close to the
ground cable attaching point as possible (Fig. 1).
(6) Start the engine in the vehicle which has the
booster battery, let the engine idle a few minutes,
then start the engine in the vehicle with the dis-
charged battery.
CAUTION: Do not crank starter motor on disabled
vehicle for more than 15 seconds, starter will over-
heat and could fail.
(7) Allow battery in disabled vehicle to charge to
at least 12.4 volts (75% charge) before attempting to
start engine. If engine does not start within 15 sec-
onds, stop cranking engine and allow starter to cool
(15 min.), before cranking again.
Fig. 1 Jumper Cable Clamp Connections
NSLUBRICATION AND MAINTENANCE 0 - 7
brakes. The secondary outlet port supplies hydraulic
pressure to the left front and right rear brakes.
POWER BRAKE VACUUM BOOSTER OPERATION
All vehicles use a 270 mm single diaphragm power
brake vacuum booster.
The power brake booster can be identified if
required, by the tag attached to the body of the
booster assembly (Fig. 10). This tag contains the fol-
lowing information: The production part number of
the power booster assembly, the date it was built,
and who was the manufacturer of the power brake
vacuum booster.
NOTE: The power brake booster assembly is not a
repairable component and must be replaced as a
complete assembly if it is found to be faulty in any
way. The check valve located in the power brake
booster (Fig. 10) is not repairable but it can be
replaced as an assembly separate from the power
brake booster.
The power brake booster reduces the amount of
force required by the driver to obtain the necessary
hydraulic pressure to stop vehicle.
The power brake booster is vacuum operated. The
vacuum is supplied from the intake manifold on the
engine through the power brake booster check valve
(Fig. 10) and (Fig. 11).
As the brake pedal is depressed, the power brake
boosters input rod moves forward (Fig. 11). This
opens and closes valves in the power booster, allow-
ing atmospheric pressure to enter on one side of a
diaphragm. Engine vacuum is always present on the
other side. This difference in pressure forces the out-
put rod of the power booster (Fig. 11) out against the
primary piston of the master cylinder. As the pistons
in the master cylinder move forward this creates the
hydraulic pressure in the brake system.The different engine combinations used on this
vehicle require that different vacuum hose routings
to the power brake vacuum booster be used.
All vacuum hoses must be routed from the engine
to the power brake vacuum booster without kinks,
excessively tight bends or potential for damage to the
vacuum hose.
The power brake vacuum booster assembly mounts
on the engine side of the dash panel, and is con-
nected to the brake pedal by the input push rod (Fig.
11). A vacuum line connects the power booster to the
intake manifold. The master cylinder is bolted to the
front of the power brake vacuum booster assembly.
RED BRAKE WARNING LAMP OPERATION
The red Brake warning lamp is located in the
instrument panel cluster and is used to indicate a
low brake fluid condition or that the parking brake is
applied. In addition, the brake warning lamp is
turned on as a bulb check by the ignition switch
every time the ignition switch is turned to the crank
position.
The warning lamp bulb is supplied a 12 volt igni-
tion feed anytime the ignition switch is on. The bulb
is then illuminated by completing the ground circuit
either through the park brake switch, the fluid level
sensor in the master cylinder reservoir, or the igni-
tion switch when it is turned to the crank position.
The Brake Fluid Level sensor is located in the
brake fluid reservoir of the master cylinder assembly.
The purpose of the sensor is to provide the driver
with an early warning that brake fluid level in the
master cylinder fluid reservoir has dropped to below
Fig. 10 Power Brake Booster Identification
Fig. 11 Power Brake Booster Assembly
5 - 8 BRAKESNS
DESCRIPTION AND OPERATION (Continued)
ABS BRAKES OPERATION AND VEHICLE
PERFORMANCE
This ABS System represents the current state-of-
the-art in vehicle braking systems and offers the
driver increased safety and control during braking.
This is accomplished by a sophisticated system of
electrical and hydraulic components. As a result,
there are a few performance characteristics that may
at first seem different but should be considered nor-
mal. These characteristics are discussed below.
NORMAL BRAKING SYSTEM FUNCTION
Under normal braking conditions, the ABS System
functions the same as a standard brake system with
a diagonally split master cylinder and conventional
vacuum assist.
ABS SYSTEM OPERATION
If a wheel locking tendency is detected during a
brake application, the brake system will enter the
ABS mode. During ABS braking, hydraulic pressure
in the four wheel circuits is modulated to prevent
any wheel from locking. Each wheel circuit is
designed with a set of electric solenoids to allow mod-
ulation, although for vehicle stability, both rear
wheel solenoids receive the same electrical signal.
During an ABS stop, the brakes hydraulic system
is still diagonally split. However, the brake system
pressure is further split into four control channels.
During antilock operation of the vehicle's brake sys-
tem the front wheels are controlled independently
and are on two separate control channels and the
rear wheels of the vehicle are controlled together.
The system can build and release pressure at each
wheel, depending on signals generated by the wheel
speed sensors (WSS) at each wheel and received at
the Controller Antilock Brake (CAB).
ABS operation is available at all vehicle speeds
above 3 to 5 mph. Wheel lockup may be perceived at
the very end of an ABS stop and is considered nor-
mal.
VEHICLE HANDLING PERFORMANCE DURING
ABS BRAKING
It is important to remember that an antilock brake
system does not shorten a vehicle's stopping distance
under all driving conditions, but does provide
improved control of the vehicle while stopping. Vehi-
cle stopping distance is still dependent on vehicle
speed, weight, tires, road surfaces and other factors.
Though ABS provides the driver with some steer-
ing control during hard braking, there are conditions
however, where the system does not provide any ben-
efit. In particular, hydroplaning is still possible when
the tires ride on a film of water. This results in the
vehicles tires leaving the road surface rendering the
vehicle virtually uncontrollable. In addition, extremesteering maneuvers at high speed or high speed cor-
nering beyond the limits of tire adhesion to the road
surface may cause vehicle skidding, independent of
vehicle braking. For this reason, the ABS system is
termed Antilock instead of Anti-Skid.
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping and/or groaning noises heard by the
driver. This is normal due to pressurized fluid being
transferred between the master cylinder and the
brakes. If ABS operation occurs during hard braking,
some pulsation may be felt in the vehicle body due to
fore and aft movement of the suspension as brake
pressures are modulated.
At the end of an ABS stop, ABS will be turned off
when the vehicle is slowed to a speed of 3±4 mph.
There may be a slight brake pedal drop anytime that
the ABS is deactivated, such as at the end of the stop
when the vehicle speed is less then 3 mph or during
an ABS stop where ABS is no longer required. These
conditions will exist when a vehicle is being stopped
on a road surface with patches of ice, loose gravel or
sand on it. Also stopping a vehicle on a bumpy road
surface will activate ABS because of the wheel hop
caused by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lock-up, some wheel slip is desired in order to
achieve optimum braking performance. Wheel slip is
defined as follows, 0 percent slip means the wheel is
rolling freely and 100 percent slip means the wheel is
fully locked. During brake pressure modulation,
wheel slip is allowed to reach up to 25 to30%. This
means that the wheel rolling velocity is 25 to 30%
less than that of a free rolling wheel at a given vehi-
cle speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lock-up.
Complete wheel lock up normally leaves black tire
marks on dry pavement. The ABS System will not
leave dark black tire marks since the wheel never
reaches a fully locked condition. Tire marks may
however be noticeable as light patched marks.
START UP CYCLE
When the ignition is turned on, a popping sound
and a slight brake pedal movement may be noticed.
Additionally, when the vehicle is first driven off a
humming may be heard and/or felt by the driver at
approximately 20 to 40 kph (12 to 25 mph). The ABS
warning lamp will also be on for up to 5 seconds
after the ignition is turned on. All of these conditions
are a normal function of ABS as the system is per-
forming a diagnosis check.
5 - 86 BRAKESNS
DESCRIPTION AND OPERATION (Continued)
The front wheel speed sensor is attached to a boss
in the steering knuckle (Fig. 7). The front tone wheel
(Fig. 7) is part of the driveshafts outboard constant
velocity joint. The rear wheel speed sensor ismounted through the rear axle, rear brake support
plate and directly to the rear bearing (Fig. 8) (Fig. 9).
The rear tone wheel on a front wheel drive vehicle is
an integral part of the rear wheel hub/bearing
assembly. If damaged though, the rear tone wheel on
a front wheel drive vehicle can be replaced as a indi-
vidual component of the rear hub/bearing assembly.
Refer to Rear Tone Wheel in the Remove And Install
Section in this group of the service manual for the
required procedure. The wheel speed sensor air gap
is NOT adjustable.
The rear tone wheel on a all wheel drive vehicle, is
part of the outboard constant velocity joint on the
rear driveshaft (Fig. 9).
The four wheel speed sensors are all serviced indi-
vidually, but the front tone wheel on all vehicles and
the rear tone wheel on all wheel drive vehicles are
serviced as part of the front or rear driveshaft out-
board constant velocity joint (Fig. 7) and (Fig. 9).
Correct ABS system operation is dependent on
accurate wheel speed signals. The vehicle's wheels
and tires must all be the same size and type to gen-
erate accurate signals. Variations in wheel and tire
size can produce inaccurate wheel speed signals,
which can cause false ABS cycles to occur.
CONTROLLER ANTILOCK BRAKES (CAB)
The Controller Antilock Brakes (CAB) is a micro-
processor based device which monitors the ABS sys-
tem during normal braking and controls it when the
vehicle is in an ABS stop. The CAB is mounted to the
bottom of the HCU (Fig. 10). The CAB uses a 25 way
electrical connector on the vehicle wiring harness.
The power source for the CAB is through the ignition
switch in the Run or On position.THE (CAB) IS ON
THE CCD BUS
Fig. 6 Proportioning Valve Mounting Location
Fig. 7 Front Wheel Speed Sensor
Fig. 8 Rear Wheel Speed Sensor (FWD)
Fig. 9 Rear Wheel Speed Sensor (AWD)
5 - 90 BRAKESNS
DESCRIPTION AND OPERATION (Continued)
The primary functions of the (CAB) are:
(1) Detect wheel locking or wheel slipping tenden-
cies by monitoring the speed of all four wheels of the
vehicle.
(2) Illuminate the TRAC lamp in the message cen-
ter on the instrument panel when a traction control
event is occurring.
(3) Control fluid modulation to the wheel brakes
while the system is in an ABS mode or the traction
control system is activated.
(4) Monitor the system for proper operation.
(5) Provide communication to the DRB Scan Tool
while in diagnostic mode.
(6) Store diagnostic information.
(7)The CAB continuously communicates with
the body controller by sending out a message to
the body controller on the CCD Bus. This mes-
sage is used for illumination of the yellow
antilock warning lamp. This is used if the ABS
controller communication is lost in the hard
wire between the body controller and the yel-
low antilock warning lamp. If the body control-
ler does not receive this message from the CAB,
the body controller will illuminate the antilock
yellow warning lamp.
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 which 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 ABS system is constantly monitored by the
CAB for proper operation. If the CAB detects a fault,
it will turn on the Amber ABS Warning Lamp anddisable the ABS braking system. The normal base
braking system will remain operational.
The CAB contains a self-diagnostic program which
will turn on the Amber ABS Warning Lamp when a
ABS system fault is detected. Faults are then stored
in a diagnostic program memory. There are multiple
fault messages which may be stored in the CAB and
displayed through the DRB Scan Tool. These fault
messages will remain in the CAB memory even after
the ignition has been turned off. The fault messages
can be read and or cleared from the CAB memory by
a technician using the DRB Scan Tool. The fault
occurrence and the fault code will also be automati-
cally cleared from the CAB memory after the identi-
cal fault has not been seen during the next 3500
miles of vehicle operation. Mileage though of the last
fault occurrence will not be automatically cleared.CONTROLLER ANTILOCK BRAKE INPUTS
²Four wheel speed sensors.
²Stop lamp switch.
²Ignition switch.
²System relay voltage.
²Ground.
²Traction Control Switch (If Equipped).
²Diagnostics Communications (CCD)
CONTROLLER ANTILOCK BRAKE OUTPUTS
²C2D Communication To Body Controller And
Instrument Cluster
²ABS warning lamp actuation.
²Traction Control Light (If Equipped).
²Diagnostic communication. (CCD)
ABS WARNING LAMP (YELLOW)
The ABS system uses a yellow colored ABS Warn-
ing Lamp. The ABS warning lamp is located on the
right side of the message center located at the top of
the instrument panel. The purpose of the warning
lamp is discussed in detail below.
The ABS warning lamp will turn on when the CAB
detects a condition which results in a shutdown of
ABS function or when the body controller does not
receive C2D messages from the CAB. When the igni-
tion key is turned to the on position, the ABS Warn-
ing Lamp is on until the CAB completes its self tests
and turns the lamp off (approximately 4 seconds
after the ignition switch is turned on). Under most
conditions, when the ABS warning lamp is on, only
the ABS function of the brake system is affected. The
standard brake system and the ability to stop the car
will not be affected when only the ABS warning lamp
is on.
The ABS warning lamp is controlled by the CAB
and the body controller through a diode located in
the wiring harness junction block. The junction block
is located under the instrument panel to the left of
Fig. 10 Controller Antilock Brake (CAB)
NSBRAKES 5 - 91
DESCRIPTION AND OPERATION (Continued)
START-UP CYCLE
The self diagnostic ABS start up cycle begins when
the ignition switch is turned to the on position. Elec-
trical checks are completed on ABS components, such
as the Controller, solenoid continuity, and the system
relay operation. During this check the Amber ABS
Warning Light is turned on for approximately 4 sec-
onds and the brake pedal may emit a popping sound
and move slightly when the solenoid valves are
checked.
DRIVE-OFF CYCLE
Further Functional testing is accomplished once
the vehicle is set in motion and reaches a speed of
about 20 kph (12 mph.). This cycle is performed only
once after each ignition on/off cycle.
²The pump/motor is activated briefly to verify
function. When the pump/motor is activated a whirl-
ing or buzzing sound may be heard by the driver,
which is normal when the pump/motor is running.
²The wheel speed sensor output is verified to be
within the correct operating range.
ONGOING TESTS
Other tests are performed on a continuous basis.
These include checks for solenoid continuity, wheel
speed sensor continuity and wheel speed sensor out-
put.
ABS DIAGNOSTIC TROUBLE CODES
Diagnostic trouble codes (DTC) are kept in the con-
troller's memory until either erased by the technician
using the DRB or erased automatically after 3500
miles. DTC's are retained by the controller even if
the ignition is turned off or the battery is discon-
nected. More than one DTC can be stored at a time.
The mileage of the most recent occurrence, number of
occurrences and the DTC that was stored is also dis-
played. Most functions of the CAB and the ABS sys-
tem can be accessed by the technician for testing and
diagnostic purposes by using the DRB.
LATCHING VERSUS NON-LATCHING
DIAGNOSTIC TROUBLE CODES
Some DTC's detected by the CAB are latching; the
DTC is latched and ABS braking is disabled until the
ignition switch is reset. Thus ABS braking is non
operational even if the original DTC has disappeared.
Other DTC's are non-latching; any warning lights
that are turned on, are only turned on as long as the
DTC condition exists. As soon as the condition goes
away, the ABS Warning Light is turned off, although
a DTC will be set in most cases.
INTERMITTENT DIAGNOSTIC TROUBLE CODES
As with virtually any electronic system, intermit-
tent electrical problems in the ABS system may be
difficult to accurately diagnose.
Most intermittent electrical problems are caused
by faulty electrical connections or wiring. When an
intermittent fault is encountered, check suspect cir-
cuits for:
A visual inspection for loose, disconnected, or mis-
routed wires should be done before attempting to
diagnose or service the ITT Teves Mark 20 antilock
brake system. A visual inspection will eliminate
unnecessary testing and diagnostics time. A thorough
visual inspection will include the following compo-
nents and areas of the vehicle.
(1) Inspect fuses in the power distribution center
(PDC) and the wiring junction block. Verify that all
fuses are fully inserted into the PDC and wring junc-
tion block. A label on the underside of the PDC cover
identifies the locations of the ABS fuses in the PDC.
(2) Inspect the 25-way electrical connector at the
CAB for damage, spread or backed-out wiring termi-
nals. Verify that the 25-way connector is fully
inserted in the socket on the CAB. Be sure that wires
are not stretched tight or pulled out of the connector.
(3) Verify that all the wheel speed sensor connec-
tions are secure.
(4) Poor mating of connector halves or terminals
not fully seated in the connector body.
(5) Improperly formed or damaged terminals. All
connector terminals in a suspect circuit should be
carefully reformed to increase contact tension.
(6) Poor terminal to wire connection. This requires
removing the terminal from the connector body to
inspect.
(7) Pin presence in the connector assembly
(8) Proper ground connections. Check all ground
connections for signs of corrosion, tight fasteners, or
other potential defects. Refer to wiring diagram man-
ual for ground locations.
(9) Problems with main power sources of the vehi-
cle. Inspect battery, generator, ignition circuits and
other related relays and fuses.
(10) 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 trouble code.
(11) Most failures of the ABS system will disable
ABS 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 failure
occurred if the failure conditions are no longer
present. The following conditions may result in inter-
mittent illumination of the ABS Warning Lamp. All
other failures will cause the lamp to remain on until
the ignition switch is turned off. Circuits involving
NSBRAKES 5 - 97
DIAGNOSIS AND TESTING (Continued)