ABS DODGE NEON 2000 Service Owner's Guide

If the CAB calculates that the brake temperatures
are high, the traction control system becomes inoper-
ative until a time-out period has elapsed. During this
ªthermo-protection mode,º the traction control func-
tion lamp illuminates TRAC OFF; note that no trou-
ble code is registered.
HYDRAULIC CIRCUITS AND VALVE OPERATION
The hydraulic shuttle valves control the flow of
pressurized brake fluid to the wheel brakes during
the different modes of ABS braking. The following
paragraphs explain how this works. For purposes of
explanation only, it is assumed that only the right
front wheel is experiencing antilock braking; the fol-
lowing diagrams show only the right front wheel in
an antilock braking operation.
NORMAL BRAKING HYDRAULIC CIRCUIT,
SOLENOID VALVE, AND SHUTTLE VALVE
FUNCTION (ABS WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 7) shows a vehicle
with traction control in the normal braking mode.
The diagram shows no wheel spin or slip occurring
relative to the speed of the vehicle. The driver is
applying the brake pedal; this builds pressure in the
brake hydraulic system to engage the brakes and
stop the vehicle. The hydraulic shuttle valve closes
with every brake pedal application so pressure is not
created at the inlet to the pump/motor.
Fig. 7 ABS With Traction Control - Normal Braking Hydraulic Circuit
1 ± OUTLET VALVE
2 ± PUMP PISTON
3 ± PUMP MOTOR (OFF)
4 ± SUCTION VALVE
5 ± LOW PRESSURE ACCUMULATOR
6 ± NORMALLY CLOSED VALVE (OFF)
7 ± TO RIGHT FRONT WHEEL8 ± NORMALLY OPEN VALVE (OFF)
9 ± NORMALLY OPEN ASR VALVE (OFF)
10 ± FROM MASTER CYLINDER
11 ± HYDRAULIC SHUTTLE VALVE
12 ± MASTER CYLINDER PRESSURE
13 ± NOISE DAMPER CHAMBER
PLBRAKES 5 - 71
DESCRIPTION AND OPERATION (Continued)

ABS BRAKING HYDRAULIC CIRCUIT, SOLENOID
VALVE, AND SHUTTLE VALVE FUNCTION (ABS
WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 8) shows the vehicle in
the ABS braking mode. The diagram shows one
wheel is slipping because the driver is attempting to
stop the vehicle at a faster rate than is allowed by
the surface on which the tires are riding.
²The hydraulic shuttle valve closes upon brake
application so that the pump/motor cannot siphon
brake fluid from the master cylinder.²The normally open and normally closed valves
modulate (build/decay) the brake hydraulic pressure
as required.
²The pump/motor is switched on so that the
brake fluid from the low pressure accumulators is
returned to the master cylinder circuits.
²The brake fluid is routed to either the master
cylinder or the wheel brake depending on the posi-
tion of the normally open valve.
Fig. 8 ABS With Traction Control - ABS Braking Hydraulic Circuit
1 ± OUTLET VALVE
2 ± PUMP PISTON
3 ± PUMP MOTOR (ON)
4 ± SUCTION VALVE
5 ± LOW PRESSURE ACCUMULATOR
6 ± NORMALLY CLOSED VALVE (MODULATING)
7 ± TO RIGHT FRONT WHEEL
8 ± NORMALLY OPEN VALVE (MODULATING)9 ± NORMALLY OPEN ASR VALVE (OFF)
10 ± FROM MASTER CYLINDER
11 ± HYDRAULIC SHUTTLE VALVE
12 ± MASTER CYLINDER PRESSURE
13 ± CONTROLLED WHEEL PRESSURE
14 ± LOW PRESSURE ACCUMULATOR PRESSURE
15 ± PUMP INTERSTAGE PRESSURE
16 ± NOISE DAMPER CHAMBER
5 - 72 BRAKESPL
DESCRIPTION AND OPERATION (Continued)

ABS TRACTION CONTROL HYDRAULIC CIRCUIT,
SOLENOID VALVE, AND SHUTTLE VALVE
FUNCTION (ABS WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 9) shows the vehicle in
the traction control (TC) mode. The diagram shows a
drive wheel is spinning and brake pressure is
required to reduce its speed.
²The normally open TC (ASR) valve is energized
to isolate the brake fluid being pumped from the
master cylinder and to isolate the driven wheel.
²The normally open TC (ASR) valve bypasses the
pump output back to the master cylinder at a fixed
pressure setting.
²The normally open and normally closed valves
modulate (build/decay) the brake pressure as
required to the spinning wheel.
Fig. 9 Traction Control Hydraulic Circuit
1 ± OUTLET VALVE
2 ± PUMP PISTON
3 ± PUMP MOTOR (ON)
4 ± LOW PRESSURE ACCUMULATOR PRESSURE
5 ± LOW PRESSURE ACCUMULATOR
6 ± NORMALLY CLOSED VALVE (MODULATING)
7 ± TO RIGHT FRONT WHEEL (SPINNING)
8 ± NORMALLY OPEN VALVE (MODULATING)
9 ± NORMALLY OPEN ASR VALVE ON (REGULATING)10 ± FROM MASTER CYLINDER
11 ± HYDRAULIC SHUTTLE VALVE
12 ± CONTROLLED WHEEL PRESSURE
13 ± SUCTION VALVE
14 ± PUMP INTERSTAGE PRESSURE
15 ± NOISE DAMPER CHAMBER
16 ± MASTER CYLINDER PRESSURE
17 ± PUMP PRESSURE
PLBRAKES 5 - 73
DESCRIPTION AND OPERATION (Continued)

DIAGNOSIS AND TESTING
SERVICE WARNINGS AND CAUTIONS
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.
CAUTION: In testing for open or short circuits, do
not ground or apply voltage to any of the circuits
unless instructed to do so for a diagnostic proce-
dure.
CAUTION: These circuits should only be tested
using a high impedance multi-meter or the DRB
scan tool 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, etc.) on a vehicle equipped
with antilock brakes may affect the function of the
antilock brake system.
ABS GENERAL DIAGNOSTICS INFORMATION
This section contains information necessary to
diagnose the antilock brake system. Specifically, this
section should be used to help diagnose conditions
which result in any of the following:
(1) amber ABS warning lamp turned on.
(2) brakes lock-up on hard application.
Diagnosis of base brake conditions that are obvi-
ously mechanical in nature should be directed to
BASE BRAKE SYSTEM at the beginning of this
group.
Many ABS conditions judged to be a problem by
the driver may be normal operating conditions. See
ABS OPERATION in the DESCRIPTION AND
OPERATION section of this group to become famil-
iarized with the normal characteristics of this
antilock brake system.
ABS WIRING DIAGRAM INFORMATION
During the diagnosis and testing of the antilock
brake system it may become necessary to reference
the wiring diagrams covering the antilock brake sys-
tem and its components. For wiring diagrams refer to
GROUP 8W of this service manual. It will provide
you with the wiring diagrams and the circuit descrip-
tion and operation information covering the antilock
brake system.
ABS VEHICLE TEST DRIVE
Most ABS complaints will require a test drive to
properly duplicate and diagnose the condition.
WARNING: CONDITIONS THAT RESULT IN TURN-
ING ON THE RED BRAKE WARNING LAMP MAY
INDICATE REDUCED BRAKING ABILITY.
Before test driving a brake complaint vehicle, note
whether the red BRAKE warning lamp, amber ABS
warning lamp, or both are turned on. If it is the red
BRAKE warning lamp, there is a brake hydraulic
problem that must be corrected before driving the
vehicle. Refer to the BASE BRAKE SYSTEM for
diagnosis of the red BRAKE warning lamp. If the red
brake warning lamp is illuminated, there is also a
possibility that there is an ABS problem and the
amber ABS warning lamp is not able to illuminate,
so the MIC turns on the red Brake warning lamp by
default.
If the amber ABS warning lamp is on, test drive
the vehicle as described below. While the amber ABS
warning lamp is on, the ABS is not functional. The
ability to stop the car using the base brake system
should not be affected.
If a functional problem of the ABS is determined
while test driving the vehicle, refer to the Chassis
Diagnostic Procedures manual.
(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 diagnostic manual.
(2) If the amber 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 and drive-off
cycles (see ABS ELECTRONIC DIAGNOSIS). If at
this time the amber ABS warning lamp comes on,
refer to the diagnostic manual.
(3) If the amber ABS warning lamp remains out,
drive the vehicle a short distance. Accelerate the
vehicle to a speed of at least 40 mph. Bring the vehi-
cle to a complete stop, braking hard enough to cause
the ABS to cycle. Again accelerate the vehicle past 25
mph. Refer to the diagnostic manual for further test-
ing of the antilock brake system.
5 - 74 BRAKESPL

ABS ELECTRONIC DIAGNOSIS
The following information is presented to give the
technician a general background on the diagnostic
capabilities of the ABS system. Complete electronic
diagnosis of the ABS system used on this vehicle is
covered in the Chassis Diagnostic Procedures manual.
Electronic diagnosis of the ABS system used on
this vehicle is performed using the DRBIIItscan
tool. The vehicle's scan tool diagnostic connector is
located under the steering column lower cover, to the
left side of the steering column (Fig. 10).
ABS SELF-DIAGNOSIS
The ABS system is equipped with a self-diagnosis
capability, which may be used to assist in the isola-
tion of ABS faults. The features are described below.
START-UP CYCLE
The self-diagnosis ABS start-up cycle begins when
the ignition switch is turned to the ON position.
Electrical checks are completed on ABS components,
including the CAB, solenoid continuity, and the relay
system operation. During this check the amber ABS
warning lamp is turned on for approximately 5 sec-
onds and the brake pedal may emit a popping sound,
moving slightly when the solenoid valves are
checked.
DRIVE-OFF CYCLE
The first time the vehicle is set in motion after an
ignition off/on cycle, the drive-off cycle occurs. This
cycle is performed when the vehicle reaches a speed
of approximately 20 kph (12 mph.).²The pump/motor is briefly activated to verify
function. When the pump/motor is briefly activated, a
whirling or buzzing sound may be heard by the
driver. This sound is normal, indicating the pump/
motor is running.
²The wheel speed sensor output correct operating
range is verified.
ONGOING TESTS
While the system is operating, these tests are per-
formed on a continuous basis:
²solenoid continuity
²wheel speed sensor continuity
²wheel speed sensor output
DIAGNOSTIC TROUBLE CODES (DTC's)
Diagnostic trouble codes (DTC's) are kept in the
controller's memory until either erased by the techni-
cian using the DRB, or erased automatically after
3500 miles or 255 ignition key cycles, whichever
occurs first. DTC's are retained by the controller
even if the ignition is turned off or the battery is dis-
connected. More than one DTC can be stored at a
time. When accessed, the number of occurrences
(ignition key cycles) and the DTC that is stored are
displayed. Most functions of the CAB and the ABS
system can be accessed by the technician for testing
and diagnostic purposes using the DRB.
LATCHING VERSUS NON-LATCHING DIAGNOSTIC TROUBLE
CODES
Some DTC's detected by the CAB are ªlatchingº
codes. The DTC is latched and ABS braking is dis-
abled 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 lamps that are turned on are only turned on
as long as the DTC condition exists; as soon as the
condition goes away, the amber ABS warning lamp is
turned off, although, in most cases, a DTC is set.
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. A visual inspection should be
done before trying to diagnose or service the antilock
brake system; this will eliminate unnecessary diag-
nosis and testing time. Perform a visual inspection
for loose, disconnected, damaged, or misrouted wires
or connectors; include the following components and
areas of the vehicle in the inspection.
(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 wiring
Fig. 10 ABS System Diagnostic Connector Location
1 ± DRIVER AIRBAG MODULE
2 ± PASSENGER AIRBAG MODULE
3 ± DATA LINK CONNECTOR
PLBRAKES 5 - 75
DIAGNOSIS AND TESTING (Continued)

junction block. A label on the underside of the PDC
cover identifies the locations of the ABS fuses.
(2) Inspect the 25-way electrical connector at the
CAB for damaged, spread, or backed-out wiring ter-
minals. Verify that the 25-way connector is fully
inserted in the socket of 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) Look for poor mating of connector halves or ter-
minals not fully seated in the connector body.
(5)
Check for improperly formed or damaged termi-
nals. All connector terminals in a suspect circuit should
be carefully reformed to increase contact tension.
(6) Look for poor terminal-to-wire connections.
This requires removing the terminal from the connec-
tor body to inspect it.
(7) Verify pin presence in the connector assembly
(8) Check for proper ground connections. Check all
ground connections for signs of corrosion, loose fas-
teners, or other potential defects. Refer to the wiring
diagrams for ground locations.
(9) Look for problems with the main power sources
of the vehicle. Inspect the battery, generator, ignition
circuits and other related relays and fuses.
If a visual check does not find the cause of the
problem, operate the car in an attempt to duplicate
the condition and record any trouble codes.
Most failures of the ABS disable the ABS function
for the entire ignition cycle even if the fault clears
before key-off. There are some failure conditions,
however, that allow ABS operation to resume during
the ignition cycle in which the trouble occurred even
if the trouble conditions are no longer present.
The following trouble conditions may result in
intermittent illumination of the amber ABS warning
lamp.
²Low 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.
²High 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 resumes.
Additional possible causes that may result in the
illumination of the amber ABS warning lamp are as
follows:
²Any condition that interrupts electrical current
to the CAB may cause the amber ABS warning lamp
to turn on intermittently.
²If PCI communication between the body control-
ler and the CAB is interrupted, the body controller
can turn on the amber ABS warning lamp.
TONE WHEEL
Tone wheels can cause erratic wheel speed sensor
signals. Inspect tone wheels for the following possible
causes:
²missing, chipped, or broken teeth
²contact with the wheel speed sensor
²wheel speed sensor to tone wheel alignment
²wheel speed sensor to tone wheel clearance
²excessive tone wheel runout
²tone wheel loose on its mounting surface
If a front tone wheel is found to need replacement,
the drive shaft must be replaced. No attempt should
be made to replace just the tone wheel. Refer to the
DIFFERENTIAL AND DRIVELINE group in this
service manual for removal and installation.
If a rear tone wheel is found to need replacement,
the rear hub and bearing must be replaced. No
attempt should be made to replace just the tone
wheel. Refer to the SUSPENSION group in this ser-
vice manual for removal and installation.
If wheel speed sensor to tone wheel contact is evi-
dent, determine the cause and correct it before
replacing the wheel speed sensor or tone wheel.
Check the gap between the speed sensor head and
the tone wheel to ensure it is within specifications.
Refer to SPECIFICATIONS in this section of the ser-
vice manual for the minimum and maximum wheel
speed sensor to tone wheel clearance.
Excessive wheel speed sensor runout can cause
erratic wheel speed sensor signals. Refer to SPECI-
FICATIONS in this section of the service manual for
the maximum allowed tone wheel runout. If tone
wheel runout is excessive, determine if it is caused
by a defect in the driveshaft assembly or hub and
bearing. Replace as necessary.
Tone wheels are pressed onto their mounting sur-
faces and should not rotate independently from the
mounting surface. Replacement of the front drive-
shaft or rear hub and bearing is necessary.
BRAKE FLUID CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts. Swelling indicates 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 the fluid sep-
arates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If the brake fluid is contaminated, drain and thor-
oughly flush the brake system. Replace all the rubber
parts or components containing rubber coming into
contact with the brake fluid including: the master
cylinder; proportioning valves; caliper seals; wheel
cylinder seals; ABS hydraulic control unit; and all
hydraulic fluid hoses.
5 - 76 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

SERVICE PROCEDURES
BRAKE FLUID LEVEL CHECKING
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.
Refer to SERVICE PROCEDURES in the BASE
BRAKE SYSTEM section in this group for the proper
procedure to check and adjust the brake fluid level in
the master cylinder fluid reservoir.
ANTILOCK BRAKE SYSTEM BLEEDING
The base brake's hydraulic system must be bled
anytime air enters the hydraulic system. The ABS
though, particularly the ICU (HCU), should only be
bled when the HCU is replaced or removed from the
vehicle. The ABS must always be bled anytime it is
suspected that the HCU has ingested air. Under
most circumstances that require the bleeding of the
brakes hydraulic system, only the base brake
hydraulic 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 the brake bleeding procedure, be sure the
brake fluid level remains close to the FULL level in
the master cylinder fluid reservoir. Check the fluid
level periodically during the bleeding procedure and
add DOT 3 brake fluid as required.
The ABS must be bled as two independent braking
systems. The non-ABS portion of the brake system
with ABS is to be bled the same as any non-ABS sys-
tem.
The ABS portion of the brake system must be bled
separately. Use the following procedure to properly
bleed the brake hydraulic system including the ABS.
BLEEDING
When bleeding the ABS system, the following
bleeding sequence must be followed to insure com-
plete and adequate bleeding.
(1) Make sure all hydraulic fluid lines are installed
and properly torqued.
(2) Connect the DRB scan tool to the diagnostics
connector. The diagnostic connector is located under
the lower steering column cover to the left of the
steering column.
(3) Using the DRB, check to make sure the CAB
does not have any fault codes stored. If it does, clear
them using the DRB.WARNING: WHEN BLEEDING THE BRAKE SYSTEM
WEAR SAFETY GLASSES. A CLEAR BLEED TUBE
MUST BE ATTACHED TO THE BLEEDER SCREWS
AND SUBMERGED IN A CLEAR CONTAINER FILLED
PART WAY WITH CLEAN BRAKE FLUID. DIRECT
THE FLOW OF BRAKE FLUID AWAY FROM YOUR-
SELF AND THE PAINTED SURFACES OF THE VEHI-
CLE. BRAKE FLUID AT HIGH PRESSURE MAY
COME OUT OF THE BLEEDER SCREWS WHEN
OPENED.
(4) Bleed the base brake system using the stan-
dard pressure or manual bleeding procedure as out-
lined in SERVICE PROCEDURES in the BASE
BRAKE SYSTEM section at the beginning of this
group.
(5) Using the DRB, select ANTILOCK BRAKES,
followed by MISCELLANEOUS, then BLEED
BRAKES. Follow the instructions displayed. When
the scan tool displays TEST COMPLETED, discon-
nect the scan tool and proceed.
(6) Bleed the base brake system a second time.
Check brake fluid level in the reservoir periodically
to prevent emptying, causing air to enter the hydrau-
lic system.
(7) Fill the master cylinder reservoir to the full
level.
(8) Test drive the vehicle to be sure the brakes are
operating correctly and that the brake pedal does not
feel spongy.
MASTER CYLINDER BLEEDING
(1) Clamp the master cylinder in a vise.
(2) Attach Master Cylinder Bleed Tube, Special
Tool 8358-1, to the primary port of the master cylin-
der and tighten in place (Fig. 11). Attach Master Cyl-
inder Bleed Tube, Special Tool 8358-2, to the
secondary port of the master cylinder and tighten in
place. Position the other end of the tubes into the
master cylinder reservoir so their outlets are below
the surface of the brake fluid in the reservoir when
filled.
(3) Fill the brake fluid reservoir with Mopart
brake fluid, or an equivalent conforming to DOT 3
specifications.
(4) Using a wooden dowel as a pushrod (Fig. 11),
press the pistons inward slowly applying brake pres-
sure, then release the pressure, allowing the pistons
to return to the released position. Repeat this several
times until all air bubbles are expelled out of the
tubes and master cylinder bore.
(5) Remove the bleed tubes from the master cylin-
der and plug the outlet ports.
(6) Install the fill cap on the reservoir.
(7) Remove the master cylinder from the vise.
PLBRAKES 5 - 77

NOTE: It is not necessary to bleed the entire
hydraulic system after replacing just the master cyl-
inder unless the brake system has been open to air
for an excessive amount of time or air is present in
the lines. Only the master cylinder must be bled
and filled.
REMOVAL AND INSTALLATION
SERVICE WARNINGS AND CAUTIONS
Review this entire section prior to performing any
mechanical work on a vehicle equipped with ABS.
This section contains information on precautions per-
taining to potential component damage, vehicle dam-
age and personal injury which could result when
servicing an ABS equipped vehicle.
CAUTION: Only the recommended jacking or hoist-
ing positions for this vehicle are to be used when-
ever it is necessary to lift a vehicle. Failure to raise
a vehicle from the recommended locations could
result in lifting a vehicle by the hydraulic control
unit mounting bracket. Lifting a vehicle by the
hydraulic control unit mounting bracket will result
in damage to the mounting bracket and the hydrau-
lic control unit.
CAUTION: An attempt to remove or disconnect cer-
tain system components may result in improper
system operation. Only those components with
approved removal and installation procedures in
this manual should be serviced.CAUTION: Brake fluid will damage painted sur-
faces. If brake fluid is spilled on any painted sur-
faces, wash off with water immediately.
CAUTION: When performing any service procedure
on a vehicle equipped with ABS do not apply a
12-volt power source to the ground circuit of the
pump motor in the HCU. Doing this will damage the
pump motor and will require replacement of the
entire HCU.
CAUTION: If welding work is to be performed on
the vehicle, using an electric arc welder, the CAB
connector should be disconnected during the weld-
ing operation.
CAUTION: The CAB 25-way connector should never
be connected or disconnected with the ignition
switch in the ON position.
Many components of the ABS System are not ser-
viceable and must be replaced as an assembly. Do not
disassemble any component which is not designed to
be serviced.
MASTER CYLINDER
NOTE: Before proceeding with this procedure,
review SERVICE WARNINGS AND CAUTIONS at the
beginning of REMOVAL AND INSTALLATION in this
section.
REMOVAL
CAUTION: The vacuum in the power brake booster
must be pumped down before removing the master
cylinder to prevent the booster from sucking in any
contamination. This can be done by pumping the
brake pedal while the engine is not running until a
firm brake pedal is achieved.
(1) With the engine not running, pump the brake
pedal 4-5 strokes until the pedal feel is firm.
(2) Disconnect the negative (ground) cable from
the battery and isolate the cable.
(3) Disconnect the positive cable from the battery,
then remove the battery from the battery tray. There
is one nut securing the clamp on the backside of the
battery holding it in place.
(4) Disconnect the wiring harness connector from
the brake fluid level switch on the master cylinder
reservoir (Fig. 12).
Fig. 11 Bleeding Master Cylinder
1 ± WOODEN DOWEL
2 ± MASTER CYLINDER
5 - 78 BRAKESPL
SERVICE PROCEDURES (Continued)

(14) Refer to DISASSEMBLY AND ASSEMBLY in
this section of this group for the procedure on sepa-
rating and reattaching the CAB to the HCU.
INSTALLATION
(1) Install the ICU onto its mounting bracket.
(2) Install the 3 bolts attaching the ICU to the
mounting bracket (Fig. 17). Tighten the 3 mounting
bolts to a torque of 11 N´m (97 in. lbs.)
(3) Install the four brake tubes going to the brakes
into their respective outlet ports on the ICU HCU
(Fig. 15). Using a crow foot on a torque wrench,
tighten the four brake tube nuts to a torque of 17
N´m (145 in. lbs.).
NOTE: When installing the brake tubes from the
master cylinder on the HCU, the brake tube with the
small tube nut is to be installed in the forward-most
port on the HCU with the small end going toward
the master cylinder secondary port.
(4) Install the primary and secondary brake tubes
from the master cylinder onto the HCU (Fig. 15). Do
not completely tighten the primary and secondary
tubes at this time.
(5) Connect the primary and secondary brake
tubes to the master cylinder ports (Fig. 15).
(6) Using a crow foot on a torque wrench, tighten
the primary and secondary brake tube nuts at both
the master cylinder and HCU to a torque of 17 N´m
(145 in. lbs.).
CAUTION: Before installing the 25-way connector
in the CAB, be sure the seal is properly installed in
the connector.(7) Install the 25-way connector into the socket of
the CAB as follows:
²Position the 25-way connector in the socket of
the CAB and carefully push it down as far as possi-
ble (Fig. 16).
²When the connector is fully seated into the CAB
socket, push the connector lock inward. This pulls
the connector into the socket of the CAB and locks it
in the installed position.
(8) Position the battery tray back in place. Install
the two bolts, then the two nuts mounting the bat-
tery tray to its bracket (Fig. 14). Tighten the two
bolts and nuts to a torque of 15 N´m (135 in. lbs.).
(9) Reinstall the air cleaner box onto its grom-
meted alignment post (Fig. 14).
(10) Install the one nut and one bolt securing the
air cleaner box in place, then connect the wiring har-
ness connector at the air inlet sensor.
(11) Install the battery and clamp it in place.
Tighten the hold-down clamp bolt to a torque of 12
N´m (105 in. lbs.).
(12) Connect the positive, then the negative
(ground) cable on the battery.
(13) Bleed the base and the ABS hydraulic sys-
tems. Refer to ANTILOCK BRAKE SYSTEM
BLEEDING in this section of this service manual
group.
(14) Fill the master cylinder to the proper fill
level.
(15) Road test the vehicle to ensure proper opera-
tion of the base and antilock brake systems.
WHEEL SPEED SENSOR (FRONT)
NOTE: Before proceeding with this procedure,
review SERVICE WARNINGS AND CAUTIONS at the
beginning of REMOVAL AND INSTALLATION in this
section.
REMOVAL
(1) Raise the vehicle. Refer to HOISTING in the
LUBRICATION AND MAINTENANCE group for the
proper lifting procedure.
(2) Disconnect the wheel speed sensor cable con-
nector from the wiring harness on the inside of the
frame rail above the front suspension crossmember
(Fig. 18). The connector has a locking tab which that
must be pulled back before the connector release
tang can be depressed, releasing the connection.
(3) Remove the speed sensor cable grommet from
the retaining bracket attached to the brake hose on
the outside of the frame rail.
(4) Remove the bolt mounting the wheel speed sen-
sor head to the steering knuckle (Fig. 19).
Fig. 17 ICU Mounting Bolts
1 ± ICU
2 ± ICU MOUNTING BOLTS
PLBRAKES 5 - 81
REMOVAL AND INSTALLATION (Continued)

CAUTION: When removing a wheel speed sensor
from the knuckle, do not use pliers on the sensor
head. This may damage the sensor head. If the sen-
sor has seized, use a hammer and a punch to tap
the edge of the sensor head ear, rocking the sensor
side-to-side until free.
(5) Carefully, remove the sensor head from the
steering knuckle.(6) Remove the screw securing the wheel speed
sensor to the rear of the strut (Fig. 20). Remove the
wheel speed sensor.
INSTALLATION
CAUTION: Failure to install speed sensor cables
properly may result in contact with moving parts or
an over extension of cables causing an open cir-
cuit. Be sure that cables are installed, routed, and
clipped properly.
(1) Attach the wheel speed sensor to the strut
using the its mounting screw (Fig. 20).
(2) Install the wheel speed sensor head in the
steering knuckle (Fig. 19). Install the mounting bolt.
Tighten the mounting bolt to a torque of 12 N´m (105
in. lbs.).
(3) From the sensor bracket on the strut, loop the
sensor cable upward, then downward at the outside
of the frame rail. Install the speed sensor cable grom-
met onto the retaining bracket attached to the brake
hose on the outside of the frame rail.
(4) Loop the wheel speed sensor cable around the
bottom of the frame rail and connect it to the wiring
harness connector on the inside of the frame rail
(Fig. 18). Remember to push in the locking tab on the
connector.
(5) Install the tire and wheel assembly.
(6) Lower the vehicle.
(7) Road test vehicle to ensure proper operation of
the base brakes and ABS.
Fig. 18 Wiring Harness Connector
1 ± RIGHT FRONT WHEEL SPEED SENSOR CONNECTOR
2 ± RIGHT FRONT DRIVESHAFT
3 ± ENGINE OIL FILTER
Fig. 19 Wheel Speed Sensor
1 ± RIGHT FRONT WHEEL SPEED SENSOR
2 ± TONE WHEEL
Fig. 20 Wheel Speed Sensor At Strut
1 ± ABS WHEEL SPEED SENSOR ROUTING BRACKET (IF
EQUIPPED)
2 ± GROUND STRAP
3 ± GROUND STRAP SCREW
4 ± ABS SENSOR BRACKET SCREW (IF EQUIPPED)
5 - 82 BRAKESPL
REMOVAL AND INSTALLATION (Continued)