four wheel drive CHRYSLER CARAVAN 2005 User Guide

FLUID
DIAGNOSIS AND TESTING - 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 Brake hydraulic unit and all hydraulic fluid
hoses.
STANDARD PROCEDURE - BRAKE FLUID
LEVEL CHECKING
Check master cylinder reservoir fluid level a mini-
mum of twice annually.
Fluid reservoirs are marked with the words FULL
and ADD to indicate proper brake fluid fill level of
the master cylinder.
If necessary, add brake fluid to bring the level to
the bottom of the FULL mark on the side of the mas-
ter cylinder fluid reservoir.
Use only Mopartbrake fluid or equivalent from a
sealed container. Brake fluid must conform to DOT 3
specifications (DOT 4 or DOT 4+ are acceptable).
DO NOTuse brake fluid with a lower boiling
point, as brake failure could result during prolonged
hard braking.
Use only brake fluid that was stored in a tightly-
sealed container.
DO NOTuse petroleum-based fluid because seal
damage will result. Petroleum based fluids would be
items such as engine oil, transmission fluid, power
steering fluid etc.
SPECIFICATIONS
BRAKE FLUID
The brake fluid used in this vehicle must conform
to DOT 3 specifications (DOT 4 and DOT 4+ are
acceptable) and SAE J1703 standards. No other type
of brake fluid is recommended or approved for usage
in the vehicle brake system. Use only MopartBrake
Fluid or equivalent from a tightly sealed container.CAUTION: Never use reclaimed brake fluid or fluid
from an container which has been left open. An
open container of brake fluid will absorb moisture
from the air and contaminate the fluid.
CAUTION: Never use any type of a petroleum-based
fluid in the brake hydraulic system. Use of such
type fluids will result in seal damage of the vehicle
brake hydraulic system causing a failure of the
vehicle brake system. Petroleum based fluids would
be items such as engine oil, transmission fluid,
power steering fluid, etc.
JUNCTION BLOCK
DESCRIPTION - NON-ABS JUNCTION BLOCK
A junction block is used on vehicles that are not
equipped with antilock brakes (ABS). The junction
block mounts in the same location as the integrated
control unit (ICU) does on vehicles equipped with
ABS. This allows for use of the same brake tube con-
figuration on all vehicles. The junction block is
located on the driver's side of the front suspension
cradle/crossmember below the master cylinder (Fig.
44).
It has six threaded ports to which the brake tubes
connect. Two are for the primary and secondary
brake tubes coming from the master cylinder. The
remaining four are for the chassis brake tubes going
to each brake assembly.
OPERATION - NON-ABS JUNCTION BLOCK
The junction block distributes the brake fluid com-
ing from the master cylinder primary and secondary
ports to the four chassis brake tubes leading to the
brakes at each wheel. Since the junction block
mounts in the same location as the ABS integrated
control unit (ICU), it allows for the common use of
brake tubes going to the brakes whether the vehicle
is equipped with or without ABS.
NOTE: Although the brake tubes coming from the
master cylinder to the junction block or ABS ICU
may appear to be the same, they are not. They are
unique to each brake system application.
RSBRAKES - BASE5-33

PROPORTIONING VALVE SPECIFICATIONS
WHEEL
BASEDRIVE
TRAINSALES
CODEBRAKE
SYSTEMSPLIT
POINTSLOPEINLET
PRESSURE
PSIOUTLET
PRESSURE
PSI
SWB FWD BRB-BGF159DISC/
DRUM W/O
ANTILOCKVAR. 0.59 1000 PSI 675-875 PSI
REMOVAL - PROPORTIONING VALVE (HEIGHT
SENSING)
(1) Using a brake pedal depressor, move and lock
the brake pedal to a position past its first 1 inch of
travel. This will prevent brake fluid from draining
out of the master cylinder when the brake tubes are
removed from the proportioning valve.
(2) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
CAUTION: Before removing the brake tubes from
the proportioning valve, the proportioning valve and
the brake tubes must be thoroughly cleaned. This is
required to prevent contamination from entering the
proportioning valve or the brake tubes.
(3) Remove the four brake tubes from the inlet and
outlet ports of the proportioning valve (Fig. 81).
(4) Remove the two bolts attaching the proportion-
ing valve and bracket to the vehicle (Fig. 81).
(5) Slide the bracket out from under rear track bar
bracket. Lower the valve down enough to pull itsactuator rod out of the axle bracket and remove the
proportioning valve from the vehicle.INSTALLATION - PROPORTIONING VALVE
(HEIGHT SENSING)
(1) Install the end of the actuator rod through the
axle bracket grommet and slide the proportioning
valve bracket under the rear track bar body bracket
(Fig. 81).
(2) Install the proportioning valve attaching bolts
(Fig. 81). Tighten the attaching bolts to a torque of
54 N´m (40 ft. lbs.).
(3) Install the four chassis brake lines into the
inlet and outlet ports of the proportioning valve (Fig.
81). Tighten all tube nuts to a torque of 17 N´m (145
in. lbs.).
CAUTION: The height sensing proportioning valve
is not adjustable. No attempt should be made to
adjust it.
(4) Bleed the brake system thoroughly to ensure
that all air has been expelled from the hydraulic sys-
tem. (Refer to 5 - BRAKES - BASE - STANDARD
PROCEDURE).
(5) Lower the vehicle to the ground.
(6) Road test the vehicle to verify proper operation
of the brake system.
ROTOR
DIAGNOSIS AND TESTING - BRAKE ROTOR
Any servicing of the rotor requires extreme care to
maintain the rotor within service tolerances to
ensure proper brake action.
Excessive runout or wobble in a rotor can increase
pedal travel due to piston knock-back. This increases
guide pin sleeve wear due to the tendency of the cal-
iper to follow the rotor wobble.
When diagnosing a brake noise or pulsation, the
machined disc braking surface should be checked and
inspected.
Fig. 81 PROPORTIONING VALVE MOUNTING
1 - LEFT REAR OUTLET TUBE
2 - RIGHT REAR OUTLET TUBE
3 - RIGHT REAR INLET TUBE
4 - MOUNTING BOLTS
5 - LEFT REAR INLET TUBE
RSBRAKES - BASE5-55
PROPORTIONING VALVE (Continued)

BRAKES - ABS
TABLE OF CONTENTS
page page
BRAKES - ABS
DESCRIPTION
DESCRIPTION - ANTILOCK BRAKE
SYSTEM............................87
DESCRIPTION - ANTILOCK BRAKE
SYSTEM (EXPORT)....................87
DESCRIPTION - ELECTRONIC VARIABLE
BRAKE PROPORTIONING...............88
DESCRIPTION - TRACTION CONTROL
SYSTEM............................88
OPERATION
OPERATION - ANTILOCK BRAKE SYSTEM . . 88
OPERATION - ELECTRONIC VARIABLE
BRAKE PROPORTIONING...............89
OPERATION - TRACTION CONTROL
SYSTEM............................89
CAUTION.............................90
STANDARD PROCEDURE - ANTILOCK BRAKE
SYSTEM BLEEDING...................90
SPECIFICATIONS
ABS FASTENER TORQUE...............91
TONE WHEEL RUNOUT................91
WHEEL SPEED SENSOR AIR GAP........91
FRONT WHEEL SPEED SENSOR
REMOVAL.............................91
INSTALLATION.........................92
REAR WHEEL SPEED SENSOR - AWD
REMOVAL.............................92INSTALLATION.........................92
REAR WHEEL SPEED SENSOR - FWD
REMOVAL.............................93
INSTALLATION.........................93
TONE WHEEL
INSPECTION - TONE WHEEL..............94
TRACTION CONTROL SWITCH
DIAGNOSIS AND TESTING - TRACTION
CONTROL SWITCH....................94
REMOVAL.............................95
INSTALLATION.........................95
HYDRAULIC/MECHANICAL
OPERATION - HYDRAULIC CIRCUITS AND
VALVES .............................95
HCU (HYDRAULIC CONTROL UNIT)
DESCRIPTION........................100
OPERATION..........................101
ICU (INTEGRATED CONTROL UNIT)
DESCRIPTION........................102
OPERATION..........................102
REMOVAL
REMOVAL - LHD.....................102
REMOVAL - RHD.....................104
DISASSEMBLY - ICU...................105
ASSEMBLY - ICU......................106
INSTALLATION
INSTALLATION - LHD.................106
INSTALLATION - RHD.................107
BRAKES - ABS
DESCRIPTION
DESCRIPTION - ANTILOCK BRAKE SYSTEM
This section covers the physical and operational
descriptions and the on-car service procedures for the
Mark 20e Antilock Brake System and the Mark 20e
Antilock Brake System with traction control.
The purpose of the antilock brake system (ABS) is
to prevent wheel lockup under braking conditions on
virtually any type of road surface. Antilock braking is
desirable because a vehicle that is stopped without
locking the wheels retains directional stability and
some steering capability. This allows the driver to
retain greater control of the vehicle during braking.
DESCRIPTION - ANTILOCK BRAKE SYSTEM
(EXPORT)
Four-wheel disc antilock brakes are standard on all
models. The Mark 20e antilock brake system is used
on all models. Depending on whether the vehicle is a
left-hand drive (LHD) or right-hand drive (RHD)
model, the integrated control unit (ICU) is located in
one of two locations. On LHD models, the ICU is
mounted above the front suspension cradle/cross-
member below the master cylinder. On RHD models,
the ICU is located behind the front suspension cra-
dle/crossmember on the left side of the vehicle.
RSBRAKES - ABS5-87

DESCRIPTION - ELECTRONIC VARIABLE
BRAKE PROPORTIONING
Vehicles equipped with ABS use electronic variable
brake proportioning (EVBP) to balance front-to-rear
braking. The EVBP is used in place of a rear propor-
tioning valve. The EVBP system uses the ABS system
to control the slip of the rear wheels in partial brak-
ing range. The braking force of the rear wheels is con-
trolled electronically by using the inlet and outlet
valves located in the integrated control unit (ICU).
EVBP activation is invisible to the customer since
there is no pump motor noise or brake pedal feedback.
DESCRIPTION - TRACTION CONTROL SYSTEM
Traction control reduces wheel slip and maintains
traction at the driving wheels at speeds below 56
km/h (35 mph) when road surfaces are slippery. The
traction control system reduces wheel slip by braking
the wheel that is losing traction.
HYDRAULIC SHUTTLE VALVES
Two pressure relief hydraulic shuttle valves are
included on vehicles with traction control. These
valves are located inside the HCU and cannot be ser-
viced separately from the HCU.
TRACTION CONTROL LAMP
The traction control function lamp is located in the
transmission range indicator display of the instru-
ment cluster, displaying TRAC, TRAC OFF or nei-
ther depending on system mode.
The TRAC OFF lamp is controlled by a Traction
Control Off switch that is a momentary contact type
switch. The Traction Control Off switch is located on
the steering column upper shroud.
OPERATION
OPERATION - ANTILOCK BRAKE SYSTEM
There are a few performance characteristics of the
Mark 20e Antilock Brake System that may at first
seem abnormal, but in fact are normal. These char-
acteristics are described below.
NORMAL BRAKING
Under normal braking conditions, the ABS func-
tions the same as a standard base brake system with
a diagonally split master cylinder and conventional
vacuum assist.
ABS BRAKING
ABS operation is available at all vehicle speeds above
3±5 mph. If a wheel locking tendency is detected during
a brake application, the brake system enters the ABS
mode. During ABS braking, hydraulic pressure in thefour wheel circuits is modulated to prevent any wheel
from locking. Each wheel circuit is designed with a set of
electric solenoids to allow modulation, although for vehi-
cle stability, both rear wheel solenoids receive the same
electrical signal. Wheel lockup may be perceived at the
very end of an ABS stop and is considered normal.
During an ABS stop, the brakes hydraulic system
is still diagonally split. However, the brake system
pressure is further split into three 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).
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping, or groaning noises heard by the
driver. This is normal and is 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 is 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 than 3 mph or during an ABS stop
where ABS is no longer required. These conditions 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 activates ABS
because of the wheel hop caused by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lockup, 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±30 percent. This means
that the wheel rolling velocity is 25±30 percent less
than that of a free rolling wheel at a given vehicle
speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lockup.
Complete wheel lockup normally leaves black tire
marks on dry pavement. The ABS will not leave dark
black tire marks since the wheel never reaches a
fully locked condition. However, tire marks may be
noticeable as light patched marks.
5 - 88 BRAKES - ABSRS
BRAKES - ABS (Continued)

For more information, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ICU (INTEGRATED CON-
TROL UNIT) - DESCRIPTION)
OPERATION
For information on the operation of the HCU as a
whole, refer to Hydraulic Circuits And Valve Opera-
tion which can be found elsewhere in this section.
For information on the operation of the components
within the HCU, refer to the following three topics.
VALVES AND SOLENOIDS
The valve block contains four inlet valves and four
outlet valves. The inlet valves are spring-loaded in
the open position and the outlet valves are spring-
loaded in the closed position during normal braking.
The fluid is allowed to flow from the master cylinder
to the wheel brakes.
During an ABS stop, these valves cycle to maintain
the proper slip ratio for each wheel. The inlet valve
closes preventing further pressure increase and the
outlet valve opens to provide a path from the wheel
brake to the HCU accumulators and pump/motor.
This releases (decays) pressure from the wheel brake,
thus releasing the wheel from excessive slippage.
Once the wheel is no longer slipping, the outlet valve
is closed and the inlet valve is opened to reapply
(build) pressure.
On vehicles with traction control, there is an extra
set of valves and solenoids. The ASR valves, mounted
in the HCU valve block, are normally in the open
position and close only when the traction control is
applied.
These isolator valves are used to isolate the rear
(non-driving) wheels of the vehicle from the hydraulic
pressure that the HCU pump/motor is sending to the
front (driving) wheels when traction control is being
applied. The rear brakes need to be isolated from the
master cylinder when traction control is being
applied so the rear wheels do not drag. For more
information, refer to Traction Control System in this
section.
BRAKE FLUID ACCUMULATORS
There are two fluid accumulators in the HCU±one
for the primary hydraulic circuit and one for the sec-
ondary hydraulic circuit. Each hydraulic circuit uses
a 5 cc accumulator.
The fluid accumulators temporarily store brake
fluid that is removed from the wheel brakes during
an ABS cycle. This stored fluid is used by the pump/
motor to provide build pressure for the brake hydrau-
lic system. When the antilock stop is complete, the
accumulators are drained by the pump/motor.
On ABS-only vehicles, there is a mini-accumulator
on the secondary hydraulic circuit that protects the
master cylinder seals during an ABS stop, and there
is a noise dampening chamber on the primary circuit.
On ABS with traction control vehicles, there are
two noise dampening chambers in the HCU.
PUMP/MOTOR
There are two pump assemblies in the HCUÐone
for the primary hydraulic circuit and one for the sec-
ondary hydraulic circuit. Both pumps are driven by a
common electric motor. This DC-type motor is inte-
gral to the HCU and is controlled by the CAB.
The pump/motor provides the extra amount of
brake fluid needed during antilock braking. Brake
fluid is released to the accumulators when the outlet
valve is opened during an antilock stop. The pump
mechanism consists of two opposing pistons operated
by an eccentric camshaft. In operation, one piston
draws fluid from the accumulators, and the opposing
piston pumps fluid to the master cylinder circuits.
When the antilock stop is complete, the pump/motor
drains the accumulators.
The CAB may turn on the pump/motor when an
antilock stop is detected. The pump/motor continues
to run during the antilock stop and is turned off after
the stop is complete. Under some conditions, the
pump/motor runs to drain the accumulators during
the next drive-off.
The pump/motor is not a serviceable item; if it
requires replacement, the HCU must be replaced.
RSBRAKES - ABS5 - 101
HCU (HYDRAULIC CONTROL UNIT) (Continued)

PARK ASSIST SYSTEM
The Park Assist System display activates an audi-
ble tone that changes from intermittent to continu-
ous as the final two Light Emitting Diodes (LED's)
are illuminated on one side or both sides of the dis-
play.
The system detection length from the rear of the
vehicle is 0.3 meters to 1.5 meters. This area extends
around the rear side of the vehicle. The system detec-
tion height from the ground is 0.2 meters to about
1.5 meters. The radio mutes when the system acti-
vates its audible tone.
When the driver selects Reverse the system scans
for objects behind the vehicle using four sensors
located in the rear bumper. A warning display above
the rear window provides both visible and audible
warnings indicating the range of the object.
The system is active only when the transmission
gear selector is in reverse for vehicle speeds less than
16 Km/h (10 mph). If the vehicle's Parking/Emer-
gency Brake is applied, the system is deactivated.
The display contains two sets of yellow and red
Light Emitting Diode's (LED's) that the driver can
see as they look over their shoulder while backing
up. Each side of the vehicle has its own warning
LED's. The system provides a visual warning by illu-
minating one or more yellow LED's as the vehicle
gets closer to the object. As the vehicle continues to
approach the object, one red LED is illuminated and
the system emits a series of short beeps. The tone
will remain constant and both red LED's are illumi-
nated once the vehicle is within 12 inches (30.5 cm)
of the object.
The system can be turned ON or OFF through the
Electronic Vehicle Information Center (EVIC) when
the vehicle is in PARK. If the park assist system is
turned OFF, a single chime will sound and the EVIC
will display the following message ªREAR PARK
ASSIST OFFº, when the vehicle is in reverse.
²Ensure that the rear bumper is free of dirt and
debris to keep the system operating properly.
²Jackhammers, large trucks, and other vibrations
could affect the performance of the system.
²Ensure that the parking brake is not applied.
If ªService Park Assist Systemº appears in the
EVIC after making sure the rear bumper is clean,
proceed to diagnose the system using a scan tool and
the appropriate diagnostic information.
WARNING
On vehicles equipped with airbags, disable
the airbag system before attempting any steer-
ing wheel, steering column, or instrument
panel component diagnosis or service. Discon-
nect and isolate the battery negative (ground)
cable, then wait two minutes for the airbag sys-
tem capacitor to discharge before performing
further diagnosis or service. This is the only
sure way to disable the airbag system. Failure
to take the proper precautions could result in
accidental airbag deployment, personal injury,
or death.
DIAGNOSIS AND TESTING - CHIME SYSTEM
Refer to the proper Body Diagnostic Procedures
manual for complete Diagnosis and Testing of the
Chime System.
NO TONE WHEN IGNITION SWITCH IS TURNED ON
AND DRIVER'S SEAT BELT IS NOT BUCKLED.
(1) Using a DRB llltscan tool, actuate chime
(BCM actuates).
(2) Using a voltmeter, check for voltage:
(a) BCM has two battery feeds at pin 1 and pin
5 of the 6±way connector.
(b) Pin 5 of the (BX2) 32 way connector of the
BCM for ignition feed.
(c) Check voltage (PX2) connector, pin 34 for 12v.
(d) If voltage OK, go to step Step 3
(e) If NO voltage repair as necessary. Refer to
the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, further details on
wire harness routing and retention, as well as pin-
out and location views for the various wire harness
connectors, splices and grounds.
(3) Check drivers seat belt buckle switch input
(from Occupant Restraint Controller (ORC) for a
closed circuit when not buckled. If input not seen,
look for open in wiring or switch. The switch is
grounded when belt is not buckled.
(4) Verify Programmable Communication Interface
(PCI) data bus communication between ORC and
BCM.
8B - 2 CHIME/BUZZERRS
CHIME/BUZZER (Continued)

trical 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 PCI bus.
OPERATION
The primary functions of the controller antilock
brake (CAB) are to:
²Monitor the antilock brake system for proper
operation.
²Detect wheel locking or wheel slipping tenden-
cies by monitoring the speed of all four wheels of the
vehicle.
²Control fluid modulation to the wheel brakes
while the system is in an ABS mode.
²Store diagnostic information.
²Provide communication to the DRBIIItscan tool
while in diagnostic mode.
²Illuminate the amber ABS warning indicator
lamp.
²(With traction control only) Illuminate the TRAC
ON lamp in the message center on the instrument
panel when a traction control event occurs.
²(with traction control only) Illuminate the TRAC
OFF lamp when the amber ABS warning indicator
lamp illuminates.
The CAB constantly monitors the antilock brake
system for proper operation. If the CAB detects a
fault, it will turn on the amber ABS warning indica-
tor lamp and disable the antilock braking system.
The normal base braking system will remain opera-
tional.
NOTE: If the vehicle is equipped with traction con-
trol, the TRAC OFF lamp will illuminate anytime the
amber ABS warning indicator lamp illuminates.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 coils then open and close the valves in the
HCU that modulate brake fluid pressure 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 CAB contains a self-diagnostic program that
monitors the antilock brake system for system faults.
When a fault is detected, the amber ABS warning
indicator lamp is turned on and the fault diagnostic
trouble code (DTC) is then stored in a diagnostic pro-
gram memory. A latched fault will disable certain
system functionality for the current ignition cycle. An
unlatched fault will disable certain system function-
ality until the fault condition disappears. These
DTC's will remain in the CAB memory even after the
ignition has been turned off. The DTC's can be read
and cleared from the CAB memory by a technician
using the DRBIIItscan tool. If not cleared with a
DRBIIItscan tool, the fault occurrence and DTC will
be automatically cleared from the CAB memory after
the identical fault has not been seen during the next
3,500 miles. Drive-off may be required for the amber
ABS warning indicator lamp to go out on the next
ignition cycle.
CAB INPUTS
²Wheel speed sensors (four)
²Brake lamp switch
²Ignition switch
²System and pump voltage
²Ground
²Traction control switch (if equipped)
²Diagnostic communication (PCI)
CAB OUTPUTS
²Amber ABS warning indicator lamp actuation
(via BUS)
²Red BRAKE warning indicator lamp actuation
(via BUS)
²Instrument cluster (MIC) communication (PCI)
²Traction control lamps (if equipped)
²Diagnostic communication (PCI, via BUS)
REMOVAL
(1) Disconnect the battery cables.
(2) Remove the battery (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/BATTERY - REMOVAL).
(3) Disconnect the vacuum hose connector at the
tank built into the battery tray.
(4) Remove the screw securing the coolant filler
neck to the battery tray.
Fig. 1 Integrated Control Unit (ICU)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
RSELECTRONIC CONTROL MODULES8E-5
CONTROLLER ANTILOCK BRAKE (Continued)

INSTALLATION
(1) Position curtain airbag over retaining holes in
roof rail and firmly snap into place (Fig. 17).
(2) Install the curtain airbag retaining bolts (Fig.
17).
(3) Engage the side curtain airbag front tether in
the A-pillar and install retaining bolt (Fig. 16).
(4) Install the bolt in the curtain airbag inflator
mounting bracket (Fig. 18).
(5) Install the retaining bolts at the d-pillar (Fig.
19).
(6) Connect the curtain airbag squib connector
(Fig. 15).
(7) Install the headliner into the vehicle (Refer to
23 - BODY/INTERIOR/HEADLINER - INSTALLA-
TION).
WARNING: Do not connect the battery negative
cable (Refer to 8 - ELECTRICAL/RESTRAINTS -
DIAGNOSIS AND TESTING - AIRBAG SYSTEM). Per-
sonal injury or death may result if the system test
is not performed first.
(8) Verify vehicle and system operation.
(9) Close hood.
DRIVER AIRBAG
DESCRIPTION
The injection molded, thermoplastic driver airbag
protective trim cover is the most visible part of the
driver airbag. The driver airbag is located in the cen-
ter of the steering wheel, where it is secured to the
steering wheel armature. Concealed beneath the
driver airbag trim cover are the horn switch, thefolded airbag cushion, the airbag cushion retainer,
the airbag housing, the airbag inflator, and the
retainers that secure the inflator to the airbag hous-
ing. The airbag cushion, housing, and inflator are
secured within an integral receptacle molded into the
back of the trim cover.
The resistive membrane-type horn switch is
secured with heat stakes to the inside surface of the
driver airbag trim cover, between the trim cover and
the folded airbag cushion. The horn switch ground
pigtail wire has a female spade terminal connector
that receives a path to ground through a male spade
terminal that is integral to the driver airbag housing
stamping and is located near the upper right corner
on the back of the housing. The horn switch feed pig-
tail wire has a white, molded plastic insulator that is
secured by an integral retainer to a mounting hole
located near the lower left corner on the back of the
housing, and is connected to the vehicle electrical
system through a take out and connector of the steer-
ing wheel wire harness.
The airbag is a multistage unit that deploys with
less force than those previously used. The airbag
inflator is a dual-initiator, non-azide, pyrotechnic-
type unit with four mounting studs and is secured to
the stamped metal airbag housing using four hex
nuts with washers. Two keyed and color-coded con-
nector receptacles on the driver airbag inflator con-
nect the two inflator initiators to the vehicle
electrical system through two yellow or black-jack-
eted, two-wire pigtail harnesses of the clockspring.
The driver airbag, trim cover, and horn switch unit
cannot be repaired, and must be replaced if deployed
or in any way damaged.
OPERATION
The Driver Airbag Trim Cover contains the horn
switch, inflator device, and a fabric bag. The driver
airbag trim cover/horn switch is not serviced sepa-
rately from the driver airbag components.
When the front airbag system is deployed, the fol-
lowingMUSTbe replaced:
²Complete Steering Column Assembly
²Lower Steering Column Coupler
²Steering Wheel.
²Clockspring.
²Driver Airbag
²Passenger Airbag
²Knee Blocker Airbag
²Upper Instrument Panel with Pad
²Front Seat Belt Buckles, both driver and passen-
ger with integral tensioners.
Fig. 19 CURTAIN AIRBAG D-PILLAR ATTACHMENT
1 - CURTAIN AIRBAG D-PILLAR ATTACHMENT LOCATIONS
2 - D-PILLAR
3 - ROOF RAIL AT REAR QUARTER GLASS
8O - 16 RESTRAINTSRS
CURTAIN AIRBAG (Continued)

SEAT BELT TENSIONER
DESCRIPTION
The seat belt system incorporates Seat Belt Ten-
sioners. The tensioner is designed to hold the occu-
pant in their respective seat by retracting the seat
belt up to four inches. They are integral to the front
seat belt buckles and cannot be serviced. If found
defective they must be replaced. After an airbag
deployment, the tensioner must be replaced.
Seat Belt Tensioners supplement the dual front air-
bag system. The seat belt tensioners are integral to
the front seat belt buckles, which are secured to the
seat cushion frame on the inboard side. The seat belt
tensioners are controlled by the Occupant Restraint
Controller (ORC) and are connected to the vehicle
electrical system through the body wire harness.
The seat belt tensioners cannot be repaired and, if
faulty or damaged, the entire front seat belt buckle
must be replaced. The seat belt tensioners are not
intended for reuse and must be replaced following
any front airbag deployment.
OPERATION
WARNING: When the front airbag is deployed, the
tensioner will have deployed also and should be
replaced. Failure to do so could result in occupant
personal injury or death.
The seat belt tensioners are deployed by a signal
generated by the Occupant Restraint Controller
(ORC) through the driver or passenger seat belt ten-
sioner line 1 and line 2 (or squib) circuits. When the
ORC sends the proper electrical signal to the tension-
ers, the electrical energy generates enough heat to
initiate a small pyrotechnic gas generator.
Removing excess slack from the front seat belts not
only keeps the occupants properly positioned for an
airbag deployment following a frontal impact of the
vehicle, but also helps to reduce injuries that the
occupants of the front seat might experience in these
situations as a result of a harmful contact with the
steering wheel, steering column, instrument panel
and/or windshield.
The ORC monitors the condition of the seat belt
tensioners through circuit resistance, and will illumi-
nate the airbag indicator in the ElectroMechanical
Instrument Cluster (EMIC) and store a Diagnostic
Trouble Code (DTC) for any fault that is detected.
For proper diagnosis of the seat belt tensioners, use a
scan tool and the appropriate diagnostic information.
SEAT WEIGHT BLADDER &
PRESSURE SENSOR
DESCRIPTION
Vehicles equipped with the Occupant Classification
System (OCS) have a seat weight bladder and pres-
sure sensor unit (Fig. 54) that is integral to the pas-
senger front seat cushion. The bladder is sandwiched
between the seat cushion pan and seat cushion foam.
The bladder consists of two rectangular sheets of
an elastomeric material and a molded plastic elbow
fitting. The two sheets of material are sealed
together around their perimeter and heat staked to
each other at numerous regular points within their
field. The elbow fitting is sealed to a small round
hole in the lower surface of the bladder and is
pointed downward where it passes through a clear-
ance hole in the insulator pad and extends to just
below the seat cushion. The bladder is then filled
with a silicone fluid to become a pliable, quilted
membrane.
Under the seat cushion a short tube is securely
clamped at one end to the bladder nipple, and at the
other end to a nipple on the electronic pressure sen-
sor. The sensor housing features an integral mount
that snaps over a tab integral to the stamped steel
Occupant Classification Module (OCM) mounting
bracket welded to the underside of the passenger
front seat cushion frame.
Fig. 54 SEAT WEIGHT BLADDER AND PRESSURE
SENSOR - TYPICAL
1 - FASTENER (2)
2 - BLADDER
3-PAD
4 - TUBE
5 - PRESSURE SENSOR
RSRESTRAINTS8O-43

The process of elimination can be used to detect
any unit which slips and to confirm proper operation
of good units. Road test analysis can diagnose slip-
ping units, but the cause of the malfunction cannot
be determined. Practically any condition can be
caused by leaking hydraulic circuits or sticking
valves.
DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TESTS
Pressure testing is a very important step in the
diagnostic procedure. These tests usually reveal the
cause of most hydraulic transaxle problems.
Before performing pressure tests, be certain that
fluid level and condition, and shift cable adjustments
have been checked and approved. Fluid must be at
operating temperature (150 to 200 degrees F.).
Install an engine tachometer, raise vehicle on hoist
which allows front wheels to turn, and position
tachometer so it can be read.
Attach 300 psi gauge (C-3293SP) to port(s)
required for test(s) being conducted. Use adapter set
L-4559 to adapt gauge(s) to transaxle.
Test port locations are shown in (Fig. 4).
TEST ONE-SELECTOR IN LOW (1st GEAR)
(1) Attach pressure gauge to the low/reverse clutch
tap.
(2) Move selector lever to the (L) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
to 20 mph.
(4) Low/reverse clutch pressure should read 115 to
145 psi.(5) This test checks pump output, pressure regula-
tion and condition of the low/reverse clutch hydraulic
circuit and shift schedule.
TEST TWO-SELECTOR IN DRIVE (2nd GEAR)
NOTE: This test checks the underdrive clutch
hydraulic circuit as well as the shift schedule.
(1) Attach gauge to the underdrive clutch tap.
(2) Move selector lever to the 3 position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 30 mph.
(4) In second gear the underdrive clutch pressure
should read 110 to 145 psi.
TEST TWO A±SELECTOR IN OD (4th Gear)
NOTE: This test checks the underdrive clutch
hydraulic circuit as well as the shift schedule.
(1) Attach gauge to the underdrive clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow wheels to rotate freely and increase
throttle opening to achieve an indicated speed of 40
mph.
(4) Underdrive clutch pressure should read below
5 psi. If not, then either the solenoid assembly or
PCM/TCM is at fault.
TEST THREE-OVERDRIVE CLUTCH CHECK (3rd and
2nd Gear)
(1) Attach gauge to the overdrive clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 20 mph. Vehicle should be in 3rd gear.
(4) Overdrive clutch pressure should read 74 to 95
psi.
(5) Move selector lever to the (3) position and
increase indicated vehicle speed to 30 mph.
(6) The vehicle should be in second gear and over-
drive clutch pressure should be less than 5 psi.
(7) This test checks the overdrive clutch hydraulic
circuit as well as the shift schedule.
TEST FOUR-SELECTOR IN OVERDRIVE (4th Gear)
(1) Attach gauge to the 2/4 clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow vehicle front wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 30 mph. Vehicle should be in 4th gear.
(4) The 2/4 clutch pressure should read 75 to 95
psi.
(5) This test checks the 2/4 clutch hydraulic cir-
cuit.
Fig. 4 Pressure Taps
1 - OVERDRIVE CLUTCH
2 - TORQUE CONVERTER OFF
3 - LOW/REVERSE CLUTCH
4 - 2/4 CLUTCH
5 - REVERSE CLUTCH
6 - UNDERDRIVE CLUTCH
21 - 6 40TE AUTOMATIC TRANSAXLERS
40TE AUTOMATIC TRANSAXLE (Continued)