2005 CHRYSLER CARAVAN brakes

REAR WHEEL SPEED SENSOR
- FWD
REMOVAL
(1) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
CAUTION: When disconnecting speed sensor cable
from vehicle wiring harness be careful not to dam-
age pins on the electrical connectors. Also, inspect
connectors for any signs of previous damage.
(2) Remove grommet from floor pan of vehicle and
disconnect speed sensor cable connector from vehicle
wiring harness (Fig. 2).
CAUTION: When removing rear wheel speed sensor
cable from routing clips, be sure not to damage the
routing clips. Routing clips that are molded onto
the brake hose will require replacement of the brake
hose if damaged during removal or installation of
the speed sensor cable.
(3) Carefully remove speed sensor cable from
press-in routing clips (Fig. 3).
(4) Remove bolt securing metal routing clip to rear
of axle and remove sensor cable from metal clip (Fig.
3).
(5) Remove secondary (yellow) retaining clip at
rear of wheel speed sensor head (Fig. 4).
(6) Push up on metal retaining clip (Fig. 4) until it
bottoms. This will release wheel speed sensor head
from hub and bearing. While holding metal clip up,
pull back on wheel speed sensor head removing it
from hub and bearing.(7) Remove wheel speed sensor assembly from
vehicle.
INSTALLATION
CAUTION: Proper installation of wheel speed sen-
sor cable is critical to continued system operation.
Be sure that cable is installed in routing retainers/
clips. Failure to install cable in retainers may result
in contact with moving parts or over extension of
cable, resulting in an open circuit.
CAUTION: It is important that only MoparTWheel
Bearing Grease be used for the following step appli-
cation. Other lubricants may cause sensor failure.
Fig. 2 Wheel Speed Sensor Connector
1 - CONNECTOR
2 - FLOOR PAN
3 - GROMMET
Fig. 3 SPEED SENSOR CABLE ROUTING
1 - METAL CLIP AND MOUNTING BOLT
2 - ROUTING CLIPS
Fig. 4 SENSOR CONNECTION AT HUB AND
BEARING
1 - SECONDARY SENSOR RETAINING CLIP
2 - METAL SENSOR RETAINING CLIP
3 - HUB AND BEARING
RSBRAKES - ABS5-93

(1) Lubricate the sensor O-ring with Mopar Wheel
Bearing Grease before installation into the Hub And
Bearing.If not lubricated, an improper seal may
result due to rolling of the O-ring.
(2) If metal sensor retaining clip is not in the neu-
tral installed position on hub and bearing cap, install
from the bottom, if necessary, and push clip upward
until it snaps into position.
(3) Install wheel speed sensor head into rear of
hub and bearing aligning index tab with the notch in
the top of the mounting hole. Push the sensor in
until it snaps into place on the metal retaining clip.
(4)
Install secondary (yellow) retaining clip over wheel
speed sensor head and engage the tabs on each side.
(5) Route sensor cable under leaf spring along rear
of axle. Install speed sensor cable into routing clips
on rear brake flex hose (Fig. 3).
(6) Install cable into metal routing clip and attach
it to the rear axle with mounting bolt (Fig. 3).
Tighten mounting bolt to 16 N´m (140 in. lbs.).
(7) Connect wheel speed sensor cable to vehicle
wiring harness (Fig. 2).Be sure speed sensor
cable connector is fully seated and locked into
vehicle wiring harness connector.
(8)
Install speed sensor cable grommet into hole in
floor pan making sure grommet is fully seated into hole.
(9) Lower vehicle.
(10) Road test vehicle to ensure proper operation
of the base and ABS braking systems.
TONE WHEEL
INSPECTION - TONE WHEEL
NOTE: Rear tone wheels for front-wheel-drive vehi-
cles are sealed within the hub and bearing assem-
bly and cannot be inspected or replaced.
Replacement of the hub and bearing is necessary.
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 3 -
DIFFERENTIAL & DRIVELINE/HALF SHAFT -
REMOVAL)
If a rear tone wheel is found to need replacement
on an all-wheel-drive model, the drive shaft must be
replaced. No attempt should be made to replace justthe tone wheel. (Refer to 3 - DIFFERENTIAL &
DRIVELINE/HALF SHAFT - REMOVAL)
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 5 - BRAKES - ABS/ELECTRICAL - SPEC-
IFICATIONS)
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 (Refer to 5 -
BRAKES - ABS/ELECTRICAL - SPECIFICATIONS).
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, rear driveshaft (AWD only) or rear hub and
bearing is necessary.
TRACTION CONTROL SWITCH
DIAGNOSIS AND TESTING - TRACTION
CONTROL SWITCH
(1) Remove lower steering column shroud. (Refer
to 19 - STEERING/COLUMN/LOWER SHROUD -
REMOVAL)
Fig. 5 Traction Control And Autostick Wiring
Connections
1 - TRACTION CONTROL WIRING CONNECTOR
2 - ROUTING CLIP
3 - AUTOSTICK WIRING CONNECTOR
4 - COLUMN WIRING HARNESS
5 - 94 BRAKES - ABSRS
REAR WHEEL SPEED SENSOR - FWD (Continued)

(2) Disconnect traction control switch harness from
column harness (Fig. 5).
(3) Using an ohmmeter, check for continuity
between pins 1 and 2. With the switch actuated,
there should be continuity between the two pins.
With the switch off, there should be no continuity.
REMOVAL
The traction control switch is located in the upper
shroud. (Refer to 19 - STEERING/COLUMN/UPPER
SHROUD - REMOVAL)
INSTALLATION
The traction control switch is located in the upper
shroud. (Refer to 19 - STEERING/COLUMN/UPPER
SHROUD - INSTALLATION)
HYDRAULIC/MECHANICAL
OPERATION - HYDRAULIC CIRCUITS AND
VALVES
The hydraulic fluid control 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 AND
SOLENOID VALVE FUNCTION
The hydraulic diagram (Fig. 6) shows the vehicle in
the normal braking mode of the base brake hydraulic
system. The diagram shows no wheel spin or slip
occurring relative to the speed of the vehicle. The
driver is applying the brake pedal which builds pres-
sure in the brake hydraulic system to engage the
brakes and stop the vehicle.
Fig. 6 Normal Braking Hydraulic Circuit
1 - OUTLET VALVE
2 - PUMP PISTON
3 - PUMP MOTOR (OFF)
4 - LOW PRESSURE ACCUMULATOR
5 - NORMALLY CLOSED VALVE (OFF)6 - TO RIGHT FRONT WHEEL
7 - NORMALLY OPEN VALVE (OFF)
8 - MASTER CYLINDER PRESSURE
9 - FROM MASTER CYLINDER
10 - NOISE DAMPER CHAMBER
RSBRAKES - ABS5-95
TRACTION CONTROL SWITCH (Continued)

ABS PRIMARY HYDRAULIC CIRCUIT AND
SOLENOID VALVE FUNCTION (ABS WITHOUT
TRACTION CONTROL)
The hydraulic diagram (Fig. 7) 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 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. 7 ABS Without Traction Control - Primary 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 WHEEL8 - NORMALLY OPEN VALVE (MODULATING)
9 - FROM MASTER CYLINDER
10 - MASTER CYLINDER PRESSURE
11 - CONTROLLED WHEEL PRESSURE
12 - PUMP INTERSTAGE PRESSURE
13 - NOISE DAMPER CHAMBER
5 - 96 BRAKES - ABSRS
HYDRAULIC/MECHANICAL (Continued)

ABS SECONDARY HYDRAULIC CIRCUIT AND
SOLENOID VALVE FUNCTION (ABS WITHOUT
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 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 will then be routed to either the
master cylinder or the wheel brake depending on the
position of the normally open valve.
²In the secondary circuit, 1.2 cc brake fluid is
taken in by the lip seal saver to protect the lip seals
on the master cylinder piston.
Fig. 8 ABS Without Traction Control - Secondary Hydraulic Circuit
1 - OUTLET VALVE
2 - PUMP PISTON
3 - LOW PRESSURE ACCUMULATOR PRESSURE
4 - TO RIGHT FRONT WHEEL
5 - FROM MASTER CYLINDER6 - MASTER CYLINDER PRESSURE
7 - CONTROLLED WHEEL PRESSURE
8 - PUMP INTERSTAGE PRESSURE
9 - LIP SEAL SAVER (SECONDARY CIRCUIT ONLY)
RSBRAKES - ABS5-97
HYDRAULIC/MECHANICAL (Continued)

NORMAL BRAKING HYDRAULIC CIRCUIT,
SOLENOID VALVE, AND SHUTTLE VALVE
FUNCTION (ABS WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 9) 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 which 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. 9 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
5 - 98 BRAKES - ABSRS
HYDRAULIC/MECHANICAL (Continued)

ABS BRAKING HYDRAULIC CIRCUIT, SOLENOID
VALVE, AND SHUTTLE VALVE FUNCTION (ABS
WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 10) 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. 10 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
RSBRAKES - ABS5-99
HYDRAULIC/MECHANICAL (Continued)

ABS TRACTION CONTROL HYDRAULIC CIRCUIT,
SOLENOID VALVE, AND SHUTTLE VALVE
FUNCTION (ABS WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 11) shows the vehicle
in the ABS braking mode. The diagram shows a drive
wheel is spinning and brake pressure is required to
reduce its speed.
²The normally open ASR valve is energized to iso-
late the brake fluid being pumped from the master
cylinder and to isolate the driven wheel.
²The normally open 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.
HCU (HYDRAULIC CONTROL
UNIT)
DESCRIPTION
The hydraulic control unit (HCU) is mounted to
the CAB as part of the ICU (Fig. 22). The HCU con-
trols the flow of brake fluid to the brakes using a
series of valves and accumulators. A pump/motor is
mounted on the HCU to supply build pressure to the
brakes during an ABS stop.
The HCU on a vehicle equipped with ABS and
traction control has a valve block housing that is
approximately 1 inch longer on the low pressure fluid
accumulators side than a HCU on a vehicle that is
equipped with only ABS.
Fig. 11 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
5 - 100 BRAKES - ABSRS
HYDRAULIC/MECHANICAL (Continued)