1996 CHRYSLER VOYAGER brake fluid

The ICU is located on the driver's side of the vehi-
cle, and is mounted to the front suspension cradle
(Fig. 3). TheABS onlyICU contains the following
components for controlling the brake system hydrau-
lic pressure during ABS braking: The CAB, eight
valve solenoids, (four inlet valves and four outlet
valves) fluid accumulators a pump, and an electric
motor. TheABS with traction controlICU con-
tains the following components for controlling the
brake system hydraulic pressure during ABS braking
and traction control operation: The CAB, four sole-
noid controlled inlet valves, four solenoid controlled
outlet valves, two hydraulic shuttle valves, two ASR
valves, fluid accumulators a pump and an electric
motor. Also attached to the hydraulic control unit are
the master cylinder primary and secondary brake
tubes and the brake tubes going to each wheel of the
vehicle. (Fig. 3).
CAUTION: No components of the ICU are service-
able. If any component that makes up the ICU is
diagnosed as not functioning properly it MUST be
replaced. The replaceable components of the ICU,
are the HCU and the CAB (Fig. 2) and (Fig. 3). The
mounting bracket is also replaceable as a separate
component of the ICU. The remaining components
of the ICU are not serviceable items. No attempt
should ever be made to remove or service any indi-
vidual components of the HCU. This is due to the
concern of contamination entering the HCU while
performing a service procedure. Also no attempt
should ever be made to remove or service any indi-
vidual components of the CAB.
CAUTION: At no time when servicing the ICU
should a 12 volt power source be applied to any
electrical connector of the HCU or the CAB.INLET VALVES AND SOLENOIDS
There are four inlet solenoids, one for each wheel.
In the released position they provide a fluid path
from the master cylinder to the wheel brakes of the
vehicle. When the ABS cycle has been completed the
inlet solenoids will return to their released (open)
position.
OUTLET VALVES AND SOLENOIDS
There are four outlet solenoids, one for each wheel.
In the released position they are closed to allow for
normal braking. In the actuated (open) position, they
provide a fluid path from the wheel brakes of the
vehicle to the hydraulic control unit HCU accumula-
tors and pump motor. The outlet solenoids are spring
loaded in the released (closed) position during normal
braking.
ASR VALVE (ABS WITH TRACTION CONTROL
ONLY)
On vehicles equipped with ABS having traction
control, there are two special ASR valves located in
the HCU portion of the ICU. The ASR valves are a
normally open type valve and are solenoid actuated.
The special ASR valves are used to isolate the rear
(non-driven) wheels of the vehicle from the hydraulic
pressure that the HCU pump motor is sending to the
front (driven) wheels, when the traction control sys-
tem is in operation. The rear brakes need to be iso-
lated from the master cylinder when traction control
is in operation so that the HCU can build the
required hydraulic pressure to the front brakes.
HCU BRAKE FLUID ACCUMULATORS AND NOISE
DAMPING CHAMBER
There are two brake fluid accumulators in the
HCU. There is one brake fluid accumlator for the pri-
mary and secondary hydraulic circuits. The brake
Fig. 2 Teves Mark 20 ICUFig. 3 ICU Mounting Location
5 - 88 BRAKESNS
DESCRIPTION AND OPERATION (Continued)

fluid accumulators temporarily store brake fluid that
is decayed from the wheel brakes during an ABS
cycle. This stored brake fluid is then used by the
pump in the HCU to provide build pressure for the
brake hydraulic system.
Additionally on vehicles that are equipped with
only ABS (non-traction control vehicles) there is a
mini brake fluid accumulator on the secondary
hydraulic circuit which protects the master cylinder's
seals during an ABS stop. There is also a noise
damping chamber on the primary hydraulic circuit.
On ABS equipped vehicles with traction control, in
addition to the brake fluid accumulators there are
also two noise damping chambers in the HCU.
HCU PUMP/MOTOR
The HCU (Fig. 4) contains 2 pump assemblies, one
for the primary and one for the secondary hydraulic
circuit of the brake system. Both pumps are driven
by a common electric motor (Fig. 4) which is part of
the HCU. The pumps draw brake fluid from the fluid
accumulators to supply build pressure to the brakes
during an ABS stop. The pump motor runs during
the drive-off cycle as a check and during an ABS stop
and is controlled by the CAB. The Pump/Motor
Assembly is not a serviceable item. If the pump/mo-
tor requires replacement the complete HCU (Fig. 4)
(minus the CAB) must be replaced.
ABS FUSES
The fuse for the ABS pump motor and the ABS system
are located in the power distribution center (PDC) (Fig. 5).
The PDC is located on the drivers side of the engine com-
partment forward of the strut tower. The fuse for the ABS
warning lamp in the instrument panel message center is
located in the junction block.
On vehicles equipped with traction control, the
fuse for the traction control switch is also located in
the junction block.The junction block is located on the left hand front
cowl panel on the vehicle.
ABS RELAYS
On the Teves Mark 20 Antilock Brake System both
the pump motor relay and the system relay are
located in the CAB. If either of the relays is diag-
nosed as not functioning properly the CAB will need
to be replaced. Refer to Controller Antilock Brakes in
the Removal And Installation Section in this group of
the service manual for the procedure.
PROPORTIONING VALVES
One assembly containing two proportioning valves
are used in the system, one for each rear brake
hydraulic circuit. The proportioning valve is located
on the frame rail next to the fuel tank, forward of the
right rear shock absorber (Fig. 6). Be sure replace-
ment proportioning valve assemblies have the same
split point and slope as the proportioning valve being
replaced.
WHEEL SPEED SENSORS
One Wheel Speed Sensor WSS is located at each
front and rear wheel of the vehicle (Fig. 7), (Fig. 8)
and (Fig. 9). The wheel speed sensor sends a small
AC signal to the CAB. This signal is generated by
magnetic induction created when a toothed sensor
ring (tone wheel) (Fig. 7), (Fig. 8) and (Fig. 9) passes
the stationary magnetic wheel speed sensor. The
CAB converts the AC signal generated at each wheel
into a digital signal. If a wheel locking tendency is
detected by the CAB, it will then modulate hydraulic
pressure via the HCU to prevent the wheel(s) from
locking.
Fig. 4 Teves Mark 20 HCU Pump/Motor
Fig. 5 Fuse Locations In Power Distribution Center
NSBRAKES 5 - 89
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)

the steering column. The CAB and the body control-
ler, controls the yellow ABS warning lamp by directly
grounding the circuit.
HYDRAULIC CIRCUITS AND VALVE OPERATION
Through the following operation descriptions the
function of the various hydraulic control valves in the
ABS will be described. The fluid control valves men-
tioned below, control the flow of pressurized brake
fluid to the wheel brakes during the different modes
of ABS braking.
For explanation purposes, all wheel speed sensors
except the right front are sending the same wheel
speed information. The following diagrams show only
the right front wheel in a antilock braking condition.
NORMAL BRAKING HYDRAULIC CIRCUIT AND
SOLENOID VALVE FUNCTION
This condition is the normal operation of the vehi-
cles base brake hydraulic system. The hydraulic sys-
tem circuit diagram (Fig. 11) shows a situation where
no wheel spin or slip is occurring relative to the
speed of the vehicle. The driver is applying the brake
pedal to build pressure in the brake hydraulic system
to apply the brakes and stop the vehicle.
TEVES MARK 20 ABS CIRCUIT AND
SOLENOID VALVE FUNCTION
This hydraulic circuit diagram (Fig. 12) shows the
vehicle in the ABS braking mode. This hydraulic cir-
cuit (Fig. 12) shows a situation where one wheel is
slipping because the driver is attempting to stop the
vehicle at a faster rate than the surface the vehicle's
tires are on will allow. The normally open and nor-
mally closed valves modulate the brake hydraulic
pressure as required. The pump/motor is switched on
so that the brake fluid from the low pressure accu-
mulators is returned to the master cylinder circuits.
The brake fluid will then be routed to either the mas-
ter cylinder or the wheel brake depending on the
position of the normally open valve.
TEVES MARK 20 SECONDARY ABS CIRCUIT
AND SOLENOID VALVE FUNCTION
This hydraulic circuit diagram (Fig. 13) shows the
vehicle in the ABS braking mode. This hydraulic cir-
cuit (Fig. 13) shows a situation where one wheel is
slipping because the driver is attempting to stop the
vehicle at a faster rate than the surface the vehicle's
tires are on will allow. The normally open and nor-
mally closed valves modulate the brake hydraulic
pressure as required. The pump/motor is switched on
so that the brake fluid from the low pressure accu-
Fig. 11 Normal Braking Hydraulic Circuit
5 - 92 BRAKESNS
DESCRIPTION AND OPERATION (Continued)

mulators is returned to the master cylinder circuits.
The brake fluid will then be routed to either the mas-
ter cylinder or the wheel brake depending on the
position of the normally open valve. A volume of 1.2
cc's of brake fluid is taken in by the lip seal saver
(Fig. 13) to protect the lip seals on the piston of the
master cylinder.
TEVES MARK 20 ABS WITH TRACTION
CONTROL NORMAL BRAKING HYDRAULIC
CIRCUIT ± SOLENOID AND SHUTTLE VALVE
FUNCTION
This condition is the normal operation of the vehi-
cles base brake hydraulic system when the vehicle is
equipped with ABS and traction control. The hydrau-
lic system circuit diagram (Fig. 14) shows a situation
where no wheel spin or slip is occurring relative to
the speed of the vehicle. The driver is applying the
brake pedal to build pressure in the brake hydraulic
system to apply the brakes and stop the vehicle. The
hydraulic shuttle valve (Fig. 14) closes with every
brake pedal application so pressure is not created at
the inlet to the pump.
TEVES MARK 20 ABS WITH TRACTION
CONTROL ABS BRAKING HYDRAULIC
CIRCUIT ± SOLENOID AND SHUTTLE VALVE
FUNCTION
This hydraulic circuit diagram (Fig. 15) shows a
vehicle equipped with ABS and traction control in
the ABS braking mode. This hydraulic circuit (Fig.
15) shows a situation where one wheel is slipping
because the driver is attempting to stop the vehicle
at a faster rate than the surface the vehicle's tires
are on will allow. The hydraulic shuttle valve (Fig.
15) closes upon brake application so that the pump
can not suck brake fluid from the master cylinder.
The normally open and normally closed valves mod-
ulate the brake hydraulic pressure as required. The
pump/motor is switched on so that the brake fluid
from the low pressure accumulators is returned to
the master cylinder circuits. The brake fluid will
then be routed to either the master cylinder or the
wheel brake depending on the position of the nor-
mally open valve.
Fig. 12 ABS Mode Hydraulic Circuit
NSBRAKES 5 - 93
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)

these inputs to the CAB should be investigated if a
complaint of intermittent warning system operation
is encountered.
(12) Low system voltage. If Low System Voltage is
detected by the CAB, the CAB will turn on the ABS
Warning Lamp until normal system voltage is
achieved. Once normal voltage is seen at the CAB,
normal operation resumes.
(13) High system voltage. If high system voltage is
detected by the CAB, the CAB will turn on the
Amber ABS Warning Lamp until normal system volt-
age is achieved. Once normal voltage is again
detected by the CAB, normal ABS operation will be
resumed at the next key on cycle.
(14) Additionally, any condition which results in
interruption of electrical current to the CAB or mod-
ulator assembly may cause the ABS Warning Lamp
to turn on intermittently.
(15) The body controller can turn on the (yellow)
ABS warning lamp if CCD communication between
the body controller and the CAB is interupted.
TONEWHEEL INSPECTION
CAUTION: The tone wheels used on this vehicle
equipped with the Teves Mark 20 Antilock Brake
System are different then those used on past mod-
els of this vehicle equipped with antilock brakes.
Reduced braking performance will result if this part
is used on earlier model vehicles and an accident
could result. Do not use on pre-1998 model year
vehicles.
Carefully inspect tonewheel at the suspected faulty
wheel speed sensor for missing, chipped or broken
teeth, this can cause erratic speed sensor signals.
Tonewheels should show no evidence of contact
with the wheel speed sensors. If contact was made,
determine cause and correct before replacing the
wheel speed sensor.
Excessive runout of the tonewheel can cause
erratic wheel speed sensor signals. Refer to Tone-
wheel Runout in the Specification Section in this sec-
tion of the service manual for the tonewheel runout
specification. Replace drive shaft assembly or rear
hub/bearing assembly if tonewheel runout exceeds
the specification.
Inspect tonewheels for looseness on their mounting
surfaces. Tonewheels are pressed onto their mounting
surfaces and should not rotate independently from
the mounting surface.
Check the wheel speed sensor head alignment to
the tone wheel. Also check the gap between the speed
sensor head and the tone wheel to ensure it is at
specification. Refer to Wheel Speed Sensor Clearance
in the Specification Section in this section of the ser-
vice manual.
PROPORTIONING VALVE
CAUTION: Proportioning valves (Fig. 18) should
never be disassembled.
If premature rear wheel skid occurs on hard brake
application, it could be an indication that a malfunc-
tion has occurred with one of the proportioning
valves.
If a malfunctioning proportioning valve is sus-
pected on a vehicle, refer to Proportioning Valve Test
in the Proportioning Valves Section in this group of
the service manual for the required test procedure.
BRAKE FLUID CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts.
Swollen rubber parts indicate the presence of
petroleum in the brake fluid.
To test for contamination, put a small amount of
drained brake fluid in clear glass jar. If fluid sepa-
rates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If brake fluid is contaminated, drain and thor-
oughly flush system. Replace master cylinder, propor-
tioning valve, caliper seals, wheel cylinder seals,
Antilock Brakes hydraulic unit and all hydraulic
fluid hoses.
TEST DRIVING ABS COMPLAINT VEHICLE
Most ABS complaints will require a test drive as a
part of the diagnostic procedure. The purpose of the
test drive is to duplicate the condition.
NOTE: Remember conditions that result in the
turning on of the Red BRAKE Warning Lamp may
indicate reduced braking ability. The following pro-
cedure should be used to test drive an ABS com-
plaint vehicle.
Fig. 18 Brake Proportioning Valve Identification
5 - 98 BRAKESNS
DIAGNOSIS AND TESTING (Continued)

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 hydraulic system section in the brake
group of this manual. If the ABS Warning lamp
was/is on, test drive the vehicle as described below, to
verify the complaint. While the ABS Warning Lamp
is on, the ABS is not functional. The standard brake
system and the ability to stop the car may not be
affected if only the ABS Warning Lamp is on.
Discuss with the owner of the vehicle or note any
other electrical problems or conditions that may be
occurring on the vehicle. They may have an effect on
the antilock brake system's function.
(1) Turn the key to the off position and then back
to the on position. Note whether the ABS Warning
Lamp continues to stay on. If it does, refer to the
diagnostic manual covering the ITT Teves Mark 20
ABS system for the required test procedures.
(2) If the ABS Warning Lamp goes out, shift into
gear and drive the car to a speed of 20 kph (12 mph)
to complete the ABS start up cycle. If at this time the
ABS Warning Lamp goes on refer to the ITT Teves
Mark 20 Diagnostic Manual.
(3) If the ABS Warning Lamp remains OUT, drive
the vehicle a short distance. During this test drive be
sure that the vehicle achieves at least 40 mph. Brake
to at least one complete stop in an ABS cycle, and
again accelerate to 25 mph.
(4) If a functional problem with the ABS system is
determined while test driving a vehicle, refer to the
diagnostic manual covering the ITT Teves Mark 20
ABS system for the required test procedures and
proper use of the DRB diagnostic scan tool.
ABS SERVICE PRECAUTIONS
The ABS uses an electronic control module, the
CAB. This module is designed to withstand normal
current draws associated with vehicle operation.
Care must be taken to avoid overloading the CAB
circuits.In testing for open or short circuits, do
not ground or apply voltage to any of the cir-
cuits unless instructed to do so for a diagnostic
procedure.These circuits should only be tested
using a high impedance multi-meter or the DRB
tester as described in this section. Power should
never be removed or applied to any control module
with the ignition in the ON position. Before removing
or connecting battery cables, fuses, or connectors,
always turn the ignition to the OFF position.
CAUTION: Use only factory wiring harnesses. Do
not cut or splice wiring to the brake circuits. The
addition of after-market electrical equipment (car
phone, radar detector, citizen band radio, trailer
lighting, trailer brakes, ect.) on a vehicle equippedwith antilock brakes may affect the function of the
antilock brake system.
SERVICE PROCEDURES
BRAKE FLUID LEVEL INSPECTION
CAUTION: Use only Mopar brake fluid or an equiv-
alent from a tightly sealed container. Brake fluid
must conform to DOT 3 specifications. Do not use
petroleum-based fluid because seal damage in the
brake system will result.
For the specific procedure covering the inspection
of the brake fluid level and adding brake fluid to the
reservoir, refer to the Service Adjustments Section in
this group of the service manual.
BLEEDING TEVES MARK 20 HYDRAULIC SYSTEM
The base brake system must be bled anytime air is
permitted to enter the hydraulic system, due to dis-
connection of brake lines, hoses or components. The
ABS system, particularly the HCU, should only be
bled when the HCU is replaced or removed from the
vehicle, or if there is reason to believe the HCU has
ingested air. Under most circumstances that would
require brake bleeding, only the base brake system
needs to be bled.
It is important to note that excessive air in the
brake system will cause a soft or spongy feeling
brake pedal.
During bleeding operations, be sure that the brake
fluid level remains close to the FULL level in the res-
ervoir. Check the fluid level periodically during the
bleeding procedure and add DOT 3 brake fluid as
required.
The Teves Mark 20 ABS hydraulic system and the
base brake hydraulic system must be bled as two
independent braking systems. The non ABS portion
of the brake system is to be bled the same as any
non ABS system. Refer to the Service Adjustments
section in this manual for the proper bleeding proce-
dure to be used. This brake system can be either
pressure bled or manually bled.
The ABS portion of the brake system MUST be
bled separately. This bleeding procedure requires the
use of the DRB Diagnostic Tester and the bleeding
sequence procedure outlined below.
ABS BLEEDING PROCEDURE
When bleeding the ABS system, the following
bleeding sequenceMUSTbe followed to insure com-
plete and adequate bleeding. The ABS system can be
bled using a manual bleeding procedure or standard
pressure bleeding equipment.
NSBRAKES 5 - 99
DIAGNOSIS AND TESTING (Continued)