2002 JEEP GRAND CHEROKEE Color

Wipe the governor pressure sensor and solenoid
valve with dry, lint free shop towels only. The O-rings
on the sensor and solenoid valve are the only service-
able components. Be sure the vent ports in the sole-
noid valve are open and not blocked by dirt or debris.
Replace the valve and/or sensor only when DRB scan
tool diagnosis indicates this is necessary. Or, if either
part has sustained physical damage (dented,
deformed, broken, etc.).
CAUTION: Do not turn the small screw at the end of
the solenoid valve for any reason. Turning the
screw in either direction will ruin solenoid calibra-
tion and result in solenoid failure. In addition, the
filter on the solenoid valve is NOT serviceable. Do
not try to remove the filter as this will damage the
valve housing.
INSPECTION
Inspect the throttle and manual valve levers and
shafts. Do not attempt to straighten a bent shaft or
correct a loose lever. Replace these components if
worn, bent, loose or damaged in any way.
Inspect all of the valve body mating surfaces for
scratches, nicks, burrs, or distortion. Use a straight-
edge to check surface flatness. Minor scratches may
be removed with crocus cloth using only very light
pressure.Minor distortion of a valve body mating surface
may be corrected by smoothing the surface with a
sheet of crocus cloth. Position the crocus cloth on a
surface plate, sheet of plate glass or equally flat sur-
face. If distortion is severe or any surfaces are
heavily scored, the valve body will have to be
replaced.
CAUTION: Many of the valves and plugs, such as
the throttle valve, shuttle valve plug, 1-2 shift valve
and 1-2 governor plug, are made of coated alumi-
num. Aluminum components are identified by the
dark color of the special coating applied to the sur-
face (or by testing with a magnet). Do not sand alu-
minum valves or plugs under any circumstances.
This practice could damage the special coating
causing the valves/plugs to stick and bind.
Inspect the valves and plugs for scratches, burrs,
nicks, or scores. Minor surface scratches on steel
valves and plugs can be removed with crocus cloth
butdo not round off the edges of the valve or
plug lands.Maintaining sharpness of these edges is
vitally important. The edges prevent foreign matter
from lodging between the valves and plugs and the
bore.
Inspect all the valve and plug bores in the valve
body. Use a penlight to view the bore interiors.
Replace the valve body if any bores are distorted or
scored. Inspect all of the valve body springs. The
springs must be free of distortion, warpage or broken
coils.
Check the two separator plates for distortion or
damage of any kind. Inspect the upper housing,
lower housing, 3-4 accumulator housing, and transfer
plate carefully. Be sure all fluid passages are clean
and clear. Check condition of the upper housing and
transfer plate check balls as well. The check balls
and ball seats must not be worn or damaged.
Trial fit each valve and plug in its bore to check
freedom of operation. When clean and dry, the valves
and plugs should drop freely into the bores.
Valve body bores do not change dimensionally with
use. If the valve body functioned correctly when new,
it will continue to operate properly after cleaning and
inspection. It should not be necessary to replace a
valve body assembly unless it is damaged in han-
dling.
The only serviceable valve body components are
listed below. The remaining valve body components
are serviced only as part of a complete valve body
assembly. Serviceable parts are:
²dual solenoid and harness assembly
²solenoid gasket
²solenoid case connector O-rings and shoulder
bolt
²switch valve and spring
Fig. 310 Accumulator Housing Components
1 - ACCUMULATOR PISTON
2 - 3-4 ACCUMULATOR HOUSING
3 - TEFLON SEALS
4 - PISTON SPRING
5 - COVER PLATE AND SCREWS
21 - 166 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

(8) Engine starts must be possible with shifter
lever in PARK or NEUTRAL gate positions only.
Engine starts must not be possible in any other gate
positions other than PARK or NEUTRAL.
(9) With shifter lever handle push-button not
depressed and lever detent in:
²PARK position- apply forward force on center of
handle and remove pressure. Engine start must be
possible.
²PARK position- apply rearward force on center
of handle and remove pressure. Engine start must be
possible.
²NEUTRAL position- engine start must be possi-
ble.
²NEUTRAL position, engine running and brakes
applied- Apply forward force on center of shift han-
dle. Transmission should not be able to shift into
REVERSE detent.
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn the
fluid into foam. This aerates the fluid and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has three primary causes.
(1) Internal clutch slippage, usually caused by low
line pressure, inadequate clutch apply pressure, or
clutch seal failure.
(2) A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged main cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.(3) Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²overheat that generates sludge (fluid break-
down)
²failure to reverse flush cooler and lines after
repair
²failure to replace contaminated converter after
repair
The use of non-recommended fluids can result in
transmission failure. The usual results are erratic
shifts, slippage, abnormal wear and eventual failure
due to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw-
ing the dipstick.
Engine coolant in the transmission fluid is gener-
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission, an overhaul is necessary.
The transmission cooler and lines should be
reverse flushed whenever a malfunction generates
sludge and/or debris. The torque converter should
also be replaced at the same time.
Failure to flush the cooler and lines will result in
recontamination. Flushing applies to auxiliary cool-
ers as well. The torque converter should also be
replaced whenever a failure generates sludge and
debris. This is necessary because normal converter
flushing procedures will not remove all contami-
nants.
21 - 228 AUTOMATIC TRANSMISSION - 545RFEWJ
BRAKE TRANSMISSION SHIFT INTERLOCK MECHANISM (Continued)

(9) Remove the number 2 bearing from the input
clutch hub.
(10) Remove the overdrive clutch wave snap-ring
from the input clutch retainer.
(11) Remove the UD/OD reaction plate tapered
snap-ring from the input clutch retainer.
(12) Remove the UD/OD reaction plate from the
input clutch retainer.
(13) Remove the UD/OD reaction plate flat snap-
ring from the input clutch retainer (Fig. 70).
(14) Remove the underdrive clutch pack from the
input clutch retainer (Fig. 72).
(15) Using Spring Compressor 8251, compress the
UD/OD balance piston and remove the snap-ring
from the input clutch hub (Fig. 71).
(16) Remove the UD/OD balance piston and piston
return spring from the input clutch retainer (Fig. 72).
(17) Remove the underdrive piston from the input
clutch retainer (Fig. 72).NOTE: Both the UD/OD balance piston and the
underdrive piston have seals molded onto them. If
the seal is damaged, do not attempt to install a new
seal onto the piston. The piston/seal must be
replaced as an assembly.
(18) Remove the input clutch retainer tapered
snap-ring.
(19) Separate input clutch retainer from input
clutch hub.
(20) Separate OD/reverse piston from input clutch
hub retainer (Fig. 72).
(21) Remove all seals and o-rings from the input
shaft and input hub. The o-rings on the input hub
are color coded. Be sure to make note of which o-ring
belongs in which location.
ASSEMBLY
(1) Install all new seals and o-rings onto the input
shaft and input hub. The o-rings on the input hub
are color coded. Be sure to install the correct o-ring
in the correct location.
(2) Check the transmission lubrication check valve
located in the input shaft using shop air. The valve
should only allow air flow in one direction. If the
valve allows no air flow, or air flow in both direc-
tions, the valve will need to be replaced.
(3) Lubricate all seals with MopartATF +4, type
9602, prior to installation.
(4) Assemble the OD/reverse piston onto the input
clutch hub (Fig. 73).
(5) Assemble the input clutch retainer onto the
input clutch hub.
(6) Install the input clutch retainer tapered snap-
ring with tapered side up onto the input clutch hub.
Fig. 71 Compressing UD/OD Balance Piston Using
Tool 8251
1 - PRESS
2 - TOOL 8251
3 - BALANCE PISTON
21 - 238 AUTOMATIC TRANSMISSION - 545RFEWJ
INPUT CLUTCH ASSEMBLY (Continued)

STANDARD PROCEDURE - MATCH MOUNTING
Tires and wheels are currently not match mounted
at the factory. Match mounting is a technique used to
reduce runout in the wheel/tire assembly. This means
that the high spot of the tire is aligned with the low
spot on the wheel rim. The high spot on the tire is
marked with a paint mark or a bright colored adhe-
sive label on the outboard sidewall. The low spot on
the rim is identified with a label on the outside of the
rim and a dot on the inside of the rim. If the outside
label has been removed the tire will have to be
removed to locate the dot on the inside of the rim.
Before dismounting a tire from its wheel, a refer-
ence mark should be placed on the tire at the valve
stem location. This reference will ensure that it is
remounted in the original position on the wheel.
(1) Use a dial indicator to locate the high spot of
the tire on the center tread rib (Fig. 6). Record the
indicator reading and mark the high spot on the tire.
Place a mark on the tire at the valve stem location
(Fig. 7).
(2) Break down the tire and remount it 180
degrees on the rim (Fig. 8).
(3) Measure the total runout again and mark the
tire to indicate the high spot.
(4) If runout is still excessive use the following
procedures.
(a) If the high spot is within 101.6 mm (4.0 in.)
of the first spot and is still excessive, replace the
tire.
(b) If the high spot is within 101.6 mm (4.0 in.)
of the first spot on the wheel, the wheel may be out
of specifications,(Refer to 22 - TIRES/WHEELS -
DIAGNOSIS AND TESTING).
(c) If the high spot is NOT within 101.6 mm (4.0
in.) of either high spot, draw an arrow on the tread
from second high spot to first. Break down the tire
and remount it 90 degrees on rim in that direction
(Fig. 9). This procedure will normally reduce the
runout to an acceptable amount.
Fig. 6 Dial Indicator
Fig. 7 First Measurement On Tire
1 - REFERENCE MARK
2 - 1ST MEASUREMENT
HIGH SPOT MARK TIRE AND RIM
3 - WHEEL
4 - VALVE STEM
Fig. 8 Remount Tire 180 Degrees
1 - VALVE STEM
2 - REFERENCE MARK
22 - 4 TIRES/WHEELSWJ
TIRES/WHEELS (Continued)

PAINT
TABLE OF CONTENTS
page page
PAINT
SPECIFICATIONS - PAINT CODES..........81
PAINT CODE
DESCRIPTION.........................81
BASE COAT/CLEAR COAT FINISH
DESCRIPTION.........................81PAINT TOUCH-UP
DESCRIPTION.........................82
FINESSE SANDING/BUFFING & POLISHING
DESCRIPTION.........................82
PAINT
SPECIFICATIONS - PAINT CODES
EXTERIOR COLORS
EXTERIOR COLOR DAIMLERCHRYSLER
CODE
Dark Garnet Red
PearlcoatXRV
Inferno Red Tinted
PearlcoatWEL
Woodland Brown Satin
GlowYUB
Onyx Green Pearlcoat YJR
Steel Blue Pearlcoat XBQ
Patriot Blue Pearlcoat WBT
Silverstone Metallic
ClearcoatXS5
Graphite Metallic
ClearcoatZDR
Black Clearcoat DX8
Stone White Clearcoat SW1
INTERIOR COLORS
INTERIOR COLOR DAIMLERCHRYSLER
CODE
Dark Slate Grey DV
Taupe L5
Sandstone T5
Dark Slate/Light Slate DB
LAREDO FASCIA/CLADDING COLORS
COLOR DAIMLERCHRYSLER
CODE
Dark Grey Metallic XS9
PAINT CODE
DESCRIPTION
Exterior vehicle body colors are identified on the
Body Code plate. The plate is located on the in the
engine compartment and attached to the top of the
right frame rail. Refer to the Introduction section at
the front of this manual for body code plate descrip-
tion. The paint code is also identified on the Vehicle
Safety Certification Label which is located on the
drivers door shut face. The first digit of the paint
code listed on the vehicle indicates the sequence of
application, i.e.: P = primary coat, Q = secondary
coat.
BASE COAT/CLEAR COAT
FINISH
DESCRIPTION
The original equipment finish is a multi-step pro-
cess that involves cleaning, electrodeposition (e-coat),
base coat, and clear coat steps. Additionally, selected
areas of the vehicle may be coated with an anti-chip
finish.
WJPAINT 23 - 81

PAINT TOUCH-UP
DESCRIPTION
When a painted metal surface has been scratched
or chipped, it should be touched-up as soon as possi-
ble to avoid corrosion. For best results, use Mopart
Scratch Filler/Primer, Touch-Up Paints and Clear Top
Coat. Refer to Introduction group of this manual for
Body Code Plate information.
WARNING: USE AN OSHA APPROVED BREATHING
FILTER WHEN SPRAYING PAINT OR SOLVENTS IN
A CONFINED AREA. PERSONAL INJURY CAN
RESULT.
OPERATION
(1) Scrape loose paint and corrosion from inside
scratch or chip.
(2) Clean affected area with MopartTar/Road Oil
Remover, and allow to dry.
(3) Fill the inside of the scratch or chip with a coat
of filler/primer. Do not overlap primer onto good sur-
face finish. The applicator brush should be wet
enough to puddle-fill the defect without running. Do
not stroke brush applicator on body surface. Allow
the filler/primer to dry hard.
(4) Cover the filler/primer with color touch-up
paint. Do not overlap touch-up color onto the original
color coat around the scratch or chip. Butt the new
color to the original color, if possible. Do not stroke
applicator brush on body surface. Allow touch-up
paint to dry hard.
(5) On vehicles without clear coat, the touch-up
color can be lightly finesse sanded (1500 grit) and
polished with rubbing compound.
(6) On vehicles with clear coat, apply clear top coat
to touch-up paint with the same technique as
described in Step 4. Allow clear top coat to dry hard.
If desired, Step 5 can be performed on clear top coat.
WARNING: AVOID PROLONGED SKIN CONTACT
WITH PETROLEUM OR ALCOHOL ± BASED CLEAN-
ING SOLVENTS. PERSONAL INJURY CAN RESULT.
AVOID PROLONGED SKIN CONTACT WITH PETRO-
LEUM OR ALCOHOL ± BASED CLEANING SOL-
VENTS. PERSONAL INJURY CAN RESULT.
FINESSE SANDING/BUFFING &
POLISHING
DESCRIPTION
CAUTION: Do not remove more than .5 mils of
clearcoat finish, if equipped. Base coat paint must
retain clear coat for durability.
Use a Paint Thickness Gauge #PR-ETG-2X or equiv-
alent to determine film thickness before and after
the repair.
Minor acid etching, orange peel, or smudging in
clearcoat or single-stage finishes can be reduced with
light finesse sanding, hand buffing, and polishing.If
the finish has been finesse sanded in the past,
it cannot be repeated. Finesse sanding opera-
tion should be performed by a trained automo-
tive paint technician.
23 - 82 PAINTWJ

LOCATING VACUUM LEAKS
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect the vacuum harness connector from
the back of the A/C Heater mode control switch on
the control panel.
(2) Connect the test set vacuum hose probe to each
port in the vacuum harness connector, one at a time,
and pause after each connection (Fig. 2). The test set
gauge should return to the 27 kPa (8 in. Hg.) setting
shortly after each connection is made. If OK, replace
the faulty mode control switch. If not OK, go to Step
3.(3) Determine the vacuum line color of the vacuum
circuit that is leaking. To determine the vacuum line
colors, refer to the Vacuum Circuits chart (Fig. 3).
(4) Disconnect and plug the vacuum line from the
component (fitting, actuator, valve, switch, or reser-
voir) on the other end of the leaking circuit. Instru-
ment panel disassembly or removal may be necessary
to gain access to some components.
(5) Connect the test set hose or probe to the open
end of the leaking circuit. The test set gauge should
return to the 27 kPa (8 in. Hg.) setting shortly after
each connection is made. If OK, replace the faulty
disconnected component. If not OK, go to Step 6.
(6) To locate a leak in a vacuum line, leave one
end of the line plugged and connect the test set hose
or probe to the other end. Run your fingers slowly
along the line while watching the test set gauge. The
vacuum reading will fluctuate when your fingers con-
tact the source of the leak. To repair the vacuum
line, cut out the leaking section of the line. Then,
insert the loose ends of the line into a suitable length
of 3 millimeter (1/8-inch) inside diameter rubber
hose.
Fig. 2 VACUUM CIRCUIT TEST
WJCONTROLS 24 - 11
CONTROLS (Continued)

REFRIGERANT
DESCRIPTION
The refrigerant used in this air conditioning sys-
tem is a HydroFluoroCarbon (HFC), type R-134a.
Unlike R-12, which is a ChloroFluoroCarbon (CFC),
R-134a refrigerant does not contain ozone-depleting
chlorine. R-134a refrigerant is a non-toxic, non-flam-
mable, clear, and colorless liquefied gas.
Even though R-134a does not contain chlorine, it
must be reclaimed and recycled just like CFC-type
refrigerants. This is because R-134a is a greenhouse
gas and can contribute to global warming.
OPERATION
R-134a refrigerant is not compatible with R-12
refrigerant in an air conditioning system. Even a
small amount of R-12 added to an R-134a refrigerant
system will cause compressor failure, refrigerant oil
sludge or poor air conditioning system performance.
In addition, the PolyAlkylene Glycol (PAG) synthetic
refrigerant oils used in an R-134a refrigerant system
are not compatible with the mineral-based refriger-
ant oils used in an R-12 refrigerant system.
R-134a refrigerant system service ports, service
tool couplers and refrigerant dispensing bottles have
all been designed with unique fittings to ensure that
an R-134a system is not accidentally contaminated
with the wrong refrigerant (R-12). There are also
labels posted in the engine compartment of the vehi-
cle and on the compressor identifying to service tech-
nicians that the air conditioning system is equipped
with R-134a.
REFRIGERANT OIL
DESCRIPTION
The refrigerant oil used in R-134a refrigerant sys-
tems is a synthetic-based, PolyAlkylene Glycol (PAG),
wax-free lubricant. Mineral-based R-12 refrigerant
oils are not compatible with PAG oils, and should
never be introduced to an R-134a refrigerant system.
There are different PAG oils available, and each
contains a different additive package. The 10PA17
compressor used in this vehicle is designed to use an
ND8 PAG refrigerant oil. Use only refrigerant oil of
this same type to service the refrigerant system.
OPERATION
After performing any refrigerant recovery or recy-
cling operation, always replenish the refrigerant sys-
tem with the same amount of the recommended
refrigerant oil as was removed. Too little refrigerant
oil can cause compressor damage, and too much can
reduce air conditioning system performance.PAG refrigerant oil is much more hygroscopic than
mineral oil, and will absorb any moisture it comes
into contact with, even moisture in the air. The PAG
oil container should always be kept tightly capped
until it is ready to be used. After use, recap the oil
container immediately to prevent moisture contami-
nation.
STANDARD PROCEDURE - REFRIGERANT OIL
LEVEL
When an air conditioning system is assembled at
the factory, all components except the compressor are
refrigerant oil free. After the refrigerant system has
been charged and operated, the refrigerant oil in the
compressor is dispersed throughout the refrigerant
system. The accumulator, evaporator, condenser, and
compressor will each retain a significant amount of
the needed refrigerant oil.
It is important to have the correct amount of oil in
the refrigerant system. This ensures proper lubrica-
tion of the compressor. Too little oil will result in
damage to the compressor. Too much oil will reduce
the cooling capacity of the air conditioning system.
It will not be necessary to check the oil level in the
compressor or to add oil, unless there has been an oil
loss. An oil loss may occur due to a rupture or leak
from a refrigerant line, a connector fitting, a compo-
nent, or a component seal. If a leak occurs, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system after the repair has been made.
Refrigerant oil loss will be evident at the leak point
by the presence of a wet, shiny surface around the
leak.
Refrigerant oil must be added when a accumulator,
evaporator coil, or condenser are replaced. See the
Refrigerant Oil Capacities chart. When a compressor
is replaced, the refrigerant oil must be drained from
the old compressor and measured. Drain all of the
refrigerant oil from the new compressor, then fill the
new compressor with the same amount of refrigerant
oil that was drained out of the old compressor.
Refrigerant Oil Capacities
Component ml fl oz
A/C System 130 4.40
Receiver Drier 70 2.37
Condenser 10 0.34
Evaporator 50 1.69
Compressordrain and measure
the oil from the old
compressor - see
text.
WJPLUMBING 24 - 75