light CHRYSLER VOYAGER 1996 User Guide

(8) Remove tension from front park brake cable.
Tension is removed by releasing the locking pliers
from the front park brake cable.
(9) Remove the 3 bolts mounting the wiring junc-
tion block to the instrument panel.
NOTE: When removing the lower mounting bolt,
push the park brake pedal down 5 clicks to access
the lower mounting bolt.
(10) Remove the lower bolt mounting the park
brake pedal to the body.
(11) Remove the forward bolt mounting the park
brake pedal to the body.
(12) Remove the upper bolt mounting the park
brake pedal to the body.
(13) Disconnect the electrical connector for the
brake light switch (Fig. 138).
(14) Pull downward on front park brake cable
while rotating park brake pedal mechanism out from
behind junction block.
(15) Remove park brake pedal release cable (Fig.
138) from park brake mechanism.
(16) Remove the ground switch for the red brake
warning lamp from the park brake pedal mechanism.
(17) Remove front park brake cable button from
park brake pedal mechanism. Tap end housing of
front park brake cable out of park brake pedal mech-
anism (Fig. 138).
INSTALL
(1) Install the ground switch for the red brake
warning lamp on the park brake pedal mechanism
(2) Install park brake cable end housing (Fig. 138)
into park brake pedal mechanism.
(3) Install cable retainer (Fig. 138) onto the park
brake cable strand and then install retainer into
pedal bracket.(4) Install cable strand button into the clevis on
the park brake pedal mechanism.
(5) Install wiring harness connector on red brake
warning lamp ground switch.
(6) Install the park brake release cable on the
release mechanism of the park brake pedal.
(7) Position the park brake pedal mechanism into
its installed position on the body of the vehicle.
(8) Remove the lock-out pin from the park brake
pedal release mechanism.
(9) Loosely install the top bolt (Fig. 138) mounting
the park brake pedal mechanism to the body.
(10) Loosely install the forward bolt (Fig. 138)
mounting the park brake pedal mechanism to the
body.
(11) Loosely install the lower bolt (Fig. 138)
mounting the park brake pedal mechanism to the
body.
(12) Tighten pedal mechanism attaching bolts to
28 N´m (250 in. lbs.).
(13) Verify that the park brake pedal is in the fully
released (full up) position.
(14) Raise vehicle.
(15) Install the front park brake cable on the park
brake cable equalizer.
(16) Lower vehicle.
(17) Remove the lock-out pin (Fig. 138) from the
automatic cable adjuster on the park brake pedal
mechanism.
(18) Install the electrical junction block on the
instrument panel.
(19) Install the reinforcement on the lower instru-
ment panel.
(20) Install the steering column cover on the lower
instrument panel.
(21) Install the left side kick panel.
(22) Install the sill scuff plate on the lower sill of
the left door.
Fig. 137 Locking Out Automatic AdjusterFig. 138 Park Brake Pedal Mounting
NSBRAKES 5 - 59
REMOVAL AND INSTALLATION (Continued)

MASTER CYLINDER FLUID RESERVOIR FILL TUBE
The master cylinder fluid reservoir filler neck is
removable from the master cylinder fluid reservoir.
The filler neck if required, can be replaced as a sep-
arate component of the fluid reservoir.
The filler neck is removed and installed using the
following procedure.
REMOVE
(1) Check brake fluid level in master cylinder fluid
reservoir to be sure brake fluid is not in the filler
neck. If brake fluid is in filler neck, lower fluid level
before removing filler neck from fluid reservoir
(2) Grasp filler neck at cap end (Fig. 177) and
push straight down. This will cause the filler neck to
pop out of the fluid reservoir.
INSTALL
(1) Wet the O-ring on the reservoir end of the filler
neck with fresh clean brake fluid.
(2) Position the filler neck in the opening on the
fluid reservoir. Ensure tab on filler neck (Fig. 177) is
in the groove on the front of the fluid reservoir.
(3) Push down while slightly rocking filler neck
until filler neck snaps into the fluid reservoir open-
ing.
(4) Install cap on filler neck.
(5) Check and/or add brake fluid in reservoir to
ensure it is at the correct level.
MASTER CYLINDER BRAKE FLUID LEVEL SWITCH
The master cylinder or brake fluid reservoir does
not have to be removed from the vehicle for replace-
ment of the brake fluid level sensor.
(1) Remove wiring harness connector from brake
fluid reservoir level sensor (Fig. 178).
(2) Using fingers, compress the retaining tabs on
the end of brake fluid level switch (Fig. 179).(3) With retaining tabs compressed, (Fig. 179)
grasp opposite end of brake fluid level switch and
pull it out of master cylinder brake fluid reservoir.
(4) Insert the replacement brake fluid level sensor
into brake fluid reservoir. Be sure sensor is pushed
in until retaining tabs (Fig. 179) lock it to the brake
fluid reservoir.
(5) Connect the vehicle wiring harness connector
to the brake fluid level sensor (Fig. 178).
FRONT DISC BRAKE CALIPER
CLEANING AND INSPECTION
Check for brake fluid leaks in and around dust
boot area and inboard brake pad, and for any rup-
tures, brittleness or damage to the piston dust boot.
If the dust boot is damaged, or a fluid leak is visible,
disassemble caliper assembly and install a new pis-
ton seal and dust boot, and piston if scored. Refer to
Caliper Disassembly And Re-Assembly Procedures in
Disc Brake Caliper Service in this section of the ser-
vice manual.
Fig. 177 Master Cylinder Fluid Reservoir Filler Neck
Fig. 178 Fluid Level Sensor Electrical Connection
Fig. 179 Master Cylinder Brake Fluid Level Sensor
NSBRAKES 5 - 71
DISASSEMBLY AND ASSEMBLY (Continued)

from rotor, so hydraulic fluid cannot get on rotor.
Place a small piece of wood between the piston and
caliper fingers.
(2)Carefullydepress brake pedal to hydraulically
push piston out of bore. Then apply and hold down
the brake pedal to any position beyond the first inch
of pedal travel. This will prevent loss of brake fluid
from the master cylinder.
(3) If both front caliper pistons are to be removed,
disconnect brake tube at flexible brake hose at frame
rail. Plug brake tube and remove piston from oppo-
site caliper using the same process as above for the
first piston removal.
(4) Disconnect the brake fluid flex hose from the
caliper assembly.
CAUTION: Do not use excessive force when clamp-
ing caliper in vise. Excessive vise pressure will
cause bore distortion and binding of piston.
(5) To disassemble caliper, mount in a vise
equipped with protective jaws.
(6) Remove guide pin sleeves and guide pin bush-
ings. See Removing Guide Pin Bushings in the cali-
per disassembly section of this manual.
(7) Remove the piston dust boot from the caliper
and discard (Fig. 187).
(8) Using a soft tool, such as a plastic trim stick,
work piston seal out of its groove in caliper piston
bore (Fig. 188). Discard old seal.Do not use a
screw driver or other metal tool for this opera-
tion, because of the possibility of scratching
piston bore or burring edges of seal groove.(9) Clean all parts using alcohol or a suitable sol-
vent and wipe dryusing only a lint free cloth.No
lint residue can remain in caliper bore. Clean out all
drilled passages and bores.Whenever a caliper
has been disassembled, a new boot and seal
must be installed at assembly.
(10) Inspect the piston bore for scoring or pitting.
Bores that show light scratches or corrosion can usu-
ally be cleared of the light scratches or corrosion
using crocus cloth. Bores that have deep scratches or
scoring should be honed. Use Caliper Hone, Special
Tool C-4095, or equivalent providing the diameter of
the bore is not increased more than 0.0254 mm
(0.001 inch) (Fig. 189).
(11) If the bore does not clean up within this spec-
ification, a new caliper housing should be installed.
Install a new piston if the old one is pitted or scored.
NOTE: When using Caliper Honing Tool, Special
Tool C-4095, coat the stones and bore with brake
fluid. After honing the bore, carefully clean the seal
and boot grooves with a stiff non-metallic rotary
brush.
NOTE: Use extreme care in cleaning the caliper
after honing. Remove all dirt and grit by flushing
the caliper with brake fluid; wipe dry with a clean,
lint free cloth and then clean a second time.
CAUTION: When inspecting caliper piston, do not
use anything but solvents to clean piston surface. If
surface of piston cannot be cleaned using only sol-
vents, piston must be replaced.
Fig. 187 Removing Caliper/Piston Dust Boot
Fig. 188 Removing Piston Seal From Caliper
5 - 74 BRAKESNS
DISASSEMBLY AND ASSEMBLY (Continued)

MUST always be used when installing brake
hose to caliper.
(12) Bleed the brake system (see Bleeding Brake
System).
WHEEL CYLINDER REAR DRUM BRAKE
DISASSEMBLE
To disassemble the wheel cylinders, proceed as fol-
lows:
(1) Pry boots away from cylinders and remove (Fig.
193).
(2) PressINon one piston to force out opposite
piston, cup and spring (Fig. 193). Then using a soft
tool such as a dowel rod, press out the cup and piston
that remain in the wheel cylinder.
(3) Wash wheel cylinder, pistons, and spring (Fig.
193) in clean brake fluid or alcohol;(DO NOT USE
ANY PETROLEUM BASE SOLVENTS)clean thor-
oughly and blow dry with compressed air. Inspect cyl-
inder bore and piston for scoring and pitting. (Do not
use a rag as lint from the rag will stick to bore sur-
faces.)
(4) Wheel cylinder bores and pistons that are
badly scored or pitted should be replaced. Cylinder
walls that have light scratches, or show signs of cor-
rosion, can usually be cleaned with crocus cloth,
using a circular motion. Black stains on the cylinder
walls are caused by piston cups and will not impair
operation of cylinder.
ASSEMBLE
Before assembling the pistons and new cups in the
wheel cylinders, dip them in clean brake fluid. If the
boots are deteriorated, cracked or do not fit tightly on
the pistons or the cylinder casting, install new boots.
(1) Coat cylinder bore with clean brake fluid.
(2) Lightly coat the sealing lip and outer surfaces
of the wheel cylinder cups withonly Mopar Pro-
tect-A-Cup Lubricant p/n 04883068 and no sub-
stitute.
(3) Install expansion spring with cup expanders in
cylinder. Install cups in each end of cylinder with
open end of cups facing each other (Fig. 193).
(4) Install piston in each end of cylinder having
the flat face of each piston contacting the flat face of
each cup, already installed (Fig. 193).
(5) Install a boot over each end of cylinder (Fig.
193).Be careful not to damage boot during
installation.
CLEANING AND INSPECTION
FRONT DISC BRAKE PAD LINING INSPECTION
If a visual inspection does not adequately deter-
mine the condition of the lining, a physical check will
be necessary. To check the amount of lining wear,
remove the wheel and tire assemblies, and the cali-
pers.
Remove the shoe and lining assemblies. (See Brake
Shoe Removal).
Combined shoe and lining thickness should be
measured at the thinnest part of the brake shoe
assembly.
When a shoe and lining assembly is worn to a
thickness of approximately 7.95 mm (0.313 inch) it
should be replaced.
Replacebothshoe assemblies (inboard and out-
board) on the front wheels. It is also necessary that
bothfront wheel brake shoe assembly sets be
replaced, whenever shoe assemblies on either side of
the vehicle require replacement.
If a shoe assembly does not require replacement,
reinstall it, making sure each shoe assembly is
returned to its original position. (See Brake Shoe
Installation).
REAR DISC BRAKES
BRAKE PAD LINING WEAR
If a visual inspection does not adequately deter-
mine the condition of the lining, a physical check will
be necessary. To check the amount of lining wear,
remove the wheel and tire assemblies, and the cali-
pers.
Remove the rear disc brake shoes. Refer to Rear
Disc Brake Shoe Removal in the Removal And Instal-
Fig. 192 Installing Dust Boot In Caliper Counterbore
5 - 76 BRAKESNS
DISASSEMBLY AND ASSEMBLY (Continued)

REAR DRUM BRAKE WHEEL CYLINDER
With brake drums removed, inspect the wheel cyl-
inder boots for evidence of a brake fluid leak. Visu-
ally check the boots for cuts, tears, or heat cracks. If
any of these conditions exist, the wheel cylinders
should be completely cleaned, inspected and new
parts installed.
If a wheel cylinder is leaking and the brake lining
material is saturated with brake fluid, the brake
shoes must be replaced.
BRAKE HOSE AND BRAKE LINES INSPECTION
Flexible rubber hose is used at both front brakes
and at the rear axle. Inspection of brake hoses
should be performed whenever the brake system is
serviced and every 7,500 miles or 12 months, which-
ever comes first (every engine oil change). Inspect
hydraulic brake hoses for surface cracking, scuffing,
or worn spots. If the fabric casing of the rubber hose
becomes exposed due to cracks or abrasions in the
rubber hose cover, the hose should be replaced imme-
diately. Eventual deterioration of the hose can take
place with possible burst failure. Faulty installation
can cause twisting, resulting in wheel, tire, or chassis
interference.
The steel brake tubing should be inspected period-
ically for evidence of physical damage or contact with
moving or hot components.
The flexible brake tube sections used on this vehi-
cle in the primary and secondary tubes from the
master cylinder to the ABS hydraulic control unit
connections and the chassis brake tubes between the
hydraulic control unit and the proportioning valve
must also be inspected. This flexible tubing must be
inspected for kinks, fraying and its contact with
other components of the vehicle or contact with the
body of the vehicle.
REAR WHEEL HUB AND BEARING ASSEMBLY
The rear hub and bearing assembly is designed for
the life of the vehicle and should require no mainte-
nance. The following procedure may be used for eval-
uation of bearing condition.
With wheel and brake drum removed, rotate
flanged outer ring of hub. Excessive roughness, lat-
eral play or resistance to rotation may indicate dirt
intrusion or bearing failure. If the rear wheel bear-
ings exhibit these conditions during inspection, the
hub and bearing assembly should be replaced.
Damaged bearing seals and resulting excessive
grease loss may also require bearing replacement.
Moderate grease loss from bearing is considered nor-
mal and should not require replacement of the hub
and bearing assembly.
ADJUSTMENTS
STOP LAMP SWITCH
(1) Remove stop lamp switch from its bracket by
rotating it approximately 30É in a counter-clockwise
direction.
(2) Disconnect wiring harness connector from stop
lamp switch.
(3) Hold stop lamp switch firmly in one hand.
Then using other hand, pull outward on the plunger
of the stop lamp switch until it has ratcheted out to
its fully extended position.
(4) Install the stop lamp switch into the bracket
using the following procedure. Depress the brake
pedal as far down as possible. Then while keeping
the brake pedal depressed, install the stop lamp
switch into the bracket by aligning index key on
switch with slot at top of square hole in mounting
bracket. When switch is fully installed in the square
hole of the bracket, rotate switch clockwise approxi-
mately 30É to lock the switch into the bracket.
CAUTION: Do not use excessive force when pulling
back on brake pedal to adjust the stop lamp switch.
If too much force is used, damage to the vacuum
booster, stop lamp switch or striker (Fig. 195) can
result.
(5) Connect the wiring harness connector to the
stop lamp switch.
(6) Gently pull back on brake pedal until the pedal
stops moving. This will cause the switch plunger
(Fig. 195) to ratchet backward to the correct position.
Fig. 195 Stop Light Switch Location In Vehicle
5 - 78 BRAKESNS
CLEANING AND INSPECTION (Continued)

REAR DRUM BRAKE SHOE ADJUSTMENT
NOTE: Normally, self adjusting drum brakes will
not require manual brake shoe adjustment.
Although in the event of a brake reline it is advis-
able to make the initial adjustment manually to
speed up the adjusting time.
(1) Raise the vehicle so that the rear wheels are
free to turn. See Hoisting Recommendations in the
Lubrication And Maintenance Section, at the front of
this service manual.
Remove the park brake cable, for the wheel of the
vehicle that is being worked on, from the park brake
cable equalizer (Fig. 196). This is required to gain
access to the star wheel. If the cable is not removed
from the equalizer, the cable and spring inside of the
brake drum is in the way of the star wheel.
(2) Remove rubber plug, from rear brake adjusting
hole, in the rear brake support plate (Fig. 197).(3)Be sure parking brake lever is fully
released.
(4) Insert Brake Adjusting, Special Tool C-3784 or
equivalent through the adjusting hole in support
plate and against star wheel of adjusting screw. Move
handle of tool upward until a slight drag is felt when
road wheel is rotated.
(5) Insert a thin screwdriver or piece of welding
rod into brake adjusting hole. Push adjusting lever
out of engagement with star wheel.Care should be
taken so as not to bend adjusting lever or dis-
tort lever spring.While holding adjusting lever out
of engagement, back off star wheel to ensure a free
wheel with no brake shoe drag.
(6) Repeat above adjustment at the other rear
wheel.
(7) Install adjusting hole rubber plug (Fig. 197) in
rear brake support plates.
(8) Install park brake cables on park brake cable
equalizer (Fig. 196).
PARK BRAKE SHOES (WITH REAR DISC BRAKES)
CAUTION: Before adjusting the park brake shoes
be sure that the park brake pedal is in the fully
released position. If park brake pedal is not in the
fully released position, the park brake shoes can
not be accurately adjusted.
(1) Raise vehicle.
(2) Remove tire and wheel.
(3) Remove disc brake caliper from caliper adapter
(Fig. 198). If required, refer to Rear Disc Brake Cal-
iper in the Removal And Installation Section in this
group of the service manual for the removal proce-
dure.
Fig. 196 Park Brake Cable Equlizer
Fig. 197 Brake Adjusting Hole Plug
Fig. 198 Disc Brake Caliper
NSBRAKES 5 - 79
ADJUSTMENTS (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 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)

TEVES MARK 20 ABS WITH TRACTION
CONTROL± TRACTION CONTROL HYDRAULIC
CIRCUIT ± SOLENOID AND SHUTTLE VALVE
FUNCTION
This hydraulic circuit diagram (Fig. 16) shows a
vehicle equipped with ABS and traction control in
the traction control mode. The hydraulic circuit (Fig.
16) shows a situation where a driven wheel is spin-
ning and brake pressure is required to reduce its
speed. The normally open ASR valve (Fig. 16) is ener-
gized to isolate the brake fluid being pumped from
the master cylinder and to isolate the driven wheel.
Also, the normally open ASR valve bypasses the
pump output back to the master cylinder at a fixed
pressure setting. The normally open and normally
closed valves (Fig. 16) modulate the brake pressure
as required to the spinning wheel.
DIAGNOSIS AND TESTING
ABS GENERAL DIAGNOSTICS INFORMATION
This section contains the information necessary to
diagnose the ITT Teves Mark 20 ABS Brake System.
Specifically, this section should be used to help diag-
nose conditions which result in any of the following:
(1) ABS Warning Lamp turned on.(2) Brakes Lock-up on hard application
Diagnosis of base brake conditions which are obvi-
ously mechanical in nature should be directed to
Group 5 Brakes in this service manual. This includes
brake noise, brake pulsation, lack of power assist,
parking brake, Red BRAKE Warning Lamp lighting,
or vehicle vibration during normal braking.
Many conditions that generate customer com-
plaints may be normal operating conditions, but are
judged to be a problem due to not being familiar with
the ABS system. These conditions can be recognized
without performing extensive diagnostic work, given
adequate understanding of the operating principles
and performance characteristics of the ABS. See the
ABS System Operation Section in this group of the
service manual to familiarize yourself with the oper-
ating principles of the ABS system.
ABS WIRING DIAGRAM INFORMATION
During the diagnosis of the antilock brake system
it may become necessary to reference the wiring dia-
grams covering the antilock brake system and its
components. For wiring diagrams refer to Antilock
Brakes in Group 8W of this service manual. This
group will provide you with the wiring diagrams and
the circuit description and operation information cov-
ering the antilock brake system.
Fig. 15 ABS With Traction Control ABS Braking Hydraulic Circuit
NSBRAKES 5 - 95
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)