front vents JEEP LIBERTY 2002 KJ / 1.G User Guide
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Page 706 of 1803

Following are paragraphs that briefly describe the
operation of each of the front wiper and washer sys-
tem operating modes.
CONTINUOUS WIPE MODE When the Low posi-
tion of the control knob on the right (wiper) control
stalk of the multi-function switch is selected, the
Body Control Module (BCM) energizes the wiper
on/off relay. This directs battery current through the
normally open contacts of the energized wiper on/off
relay and the normally closed contacts of the de-en-
ergized wiper high/low relay to the low speed brush
of the front wiper motor, causing the front wipers to
cycle at low speed. When the High position of the
control knob is selected, the BCM energizes both the
wiper on/off relay and the wiper high/low relay. This
directs battery current through the normally open
contacts of the energized wiper on/off relay and the
normally open contacts of the energized wiper high/
low relay to the high speed brush of the front wiper
motor, causing the front wipers to cycle at high
speed.
When the Off position of the control knob is
selected, the BCM de-energizes both the wiper on/off
and wiper high low relays, then one of two events
will occur. The event that occurs depends upon the
position of the wiper blades on the windshield at the
moment that the control knob Off position is selected.
If the wiper blades are in the down position on the
windshield when the Off position is selected, the
park switch that is integral to the front wiper motor
is closed to ground and the wiper motor ceases to
operate. If the wiper blades are not in the down posi-
tion on the windshield at the moment the Off posi-
tion is selected, the park switch is closed to battery
current from the fused ignition switch output (run-
acc) circuit of the front wiper motor. The park switch
directs this battery current to the low speed brush of
the wiper motor through the wiper park switch sense
circuit and the normally closed contacts of the de-en-
ergized wiper on/off and wiper high/low relays. This
causes the wiper motor to continue running at low
speed until the wiper blades are in the down position
on the windshield and the park switch is again
closed to ground.
INTERMITTENT WIPE MODE When the control
knob on the right (wiper) control stalk of the multi-
function switch is moved to one of the Delay interval
positions, the BCM electronic intermittent wipe logic
circuit responds by calculating the correct length of
time between wiper sweeps based upon the selected
delay interval input. The BCM monitors the chang-
ing state of the wiper motor park switch through a
hard wired front wiper park switch sense circuit
input. This input allows the BCM to determine the
proper intervals at which to energize and de-energize
the wiper on/off relay to operate the front wipermotor intermittently for one low speed cycle at a
time. The BCM logic is also programmed to provide
an immediate wipe cycle and begin a new delay
interval timing cycle each time a shorter delay inter-
val is selected, and to add the remaining delay tim-
ing interval to the new delay interval timing before
the next wipe cycle occurs each time a longer delay
interval is selected.
MIST WIPE MODE When the right (wiper) control
stalk of the multi-function switch is moved to the
momentary Mist position, the BCM energizes the
wiper on/off relay for as long as the Mist switch is
held closed, then de-energizes the relay when the
state of the Mist switch input changes to open. The
BCM can operate the front wiper motor in this mode
for only one low speed cycle at a time, or for an
indefinite number of sequential low speed cycles,
depending upon how long the Mist switch is held
closed.
WASH MODE When the right (wiper) control stalk
of the multi-function switch is moved to the momen-
tary front Wash position while the control knob is in
the Low or High positions, the circuitry within the
switch directs battery current and ground to the
washer pump/motor unit. This will cause the washer
pump/motor unit to be energized for as long as the
front Wash switch is held closed, and to de-energize
when the front Wash switch is released. When the
right (wiper) control stalk of the multi-function
switch is moved to the momentary front Wash posi-
tion while the control knob is in one of the Delay
interval positions, the front washer pump/motor oper-
ation is the same. However, the BCM energizes the
wiper on/off relay to override the selected delay inter-
val and operate the front wiper motor in a continu-
ous low speed mode for as long as the front Wash
switch is held closed, then de-energizes the relay and
reverts to the selected delay mode interval several
wipe cycles after the front Wash switch is released.
The BCM detects the front Wash switch state
through a hard wired washer pump driver circuit
input from the multi-function switch.
WIPE-AFTER-WASH MODE When the right
(wiper) control stalk of the multi-function switch is
moved to the momentary front Wash position while
the control knob is in the Off position, the BCM
detects that switch state through a hard wired
washer pump driver circuit input from the multi-
function switch. The BCM responds to this input by
energizing the wiper on/off relay for as long as the
Wash switch is held closed, then de-energizes the
relay several wipe cycles after the front Wash switch
is released. The BCM monitors the changing state of
the wiper motor park switch through a hard wired
front wiper park switch sense circuit input. This
input allows the BCM to count the number of wipe
KJFRONT WIPERS/WASHERS 8R - 5
FRONT WIPERS/WASHERS (Continued)
Page 708 of 1803

ity of the headlamp and dash wire harness connector
for the washer pump/motor unit and a good ground.
There should be no continuity. If OK, go to Step 4. If
not OK, repair the shorted washer pump driver cir-
cuit between the washer pump/motor unit and the
multi-function switch as required.
(4) Check for continuity between the washer pump
driver circuit cavities of the headlamp and dash wire
harness connector for the washer pump/motor unit
and the instrument panel wire harness connector for
the multi-function switch (Connector C-2). There
should be continuity. If OK, go to Step 5. If not OK,
repair the open washer pump driver circuit between
the washer pump/motor unit and the multi-function
switch as required.
(5) Check for continuity between the washer pump
sense circuit cavity of the headlamp and dash wire
harness connector for the washer pump/motor unit
and a good ground. There should be no continuity. If
OK, go to Step 6. If not OK, repair the shorted
washer pump sense circuit between the washer
pump/motor unit and the multi-function switch as
required.
(6) Check for continuity between the washer pump
sense circuit cavities of the headlamp and dash wire
harness connector for the washer pump/motor unit
and the instrument panel wire harness connector for
the multi-function switch (Connector C-2). There
should be continuity. If OK, replace the faulty washer
pump/motor unit. If not OK, repair the open washer
pump sense circuit between the washer pump/motor
unit and the multi-function switch as required.
CLEANING - FRONT WIPER & WASHER
SYSTEM
FRONT WIPER SYSTEM
The squeegees of wiper blades exposed to the ele-
ments for a long time tend to lose their wiping effec-
tiveness. Periodic cleaning of the squeegees is
suggested to remove any deposits of salt or road film.
The wiper blades, arms, and windshield glass should
only be cleaned using a sponge or soft cloth and
windshield washer fluid, a mild detergent, or a non-
abrasive cleaner. If the wiper blades continue to
leave streaks, smears, hazing, or beading on the
glass after thorough cleaning of the squeegees and
the glass, the entire wiper blade assembly must be
replaced.
CAUTION: Protect the rubber squeegees of the
wiper blades from any petroleum-based cleaners,
solvents, or contaminants. These products can rap-
idly deteriorate the rubber squeegees.FRONT WASHER SYSTEM
If the washer system is contaminated with foreign
material, drain the washer reservoir by removing the
washer pump/motor from the reservoir. Clean foreign
material from the inside of the washer pump/motor
inlet filter screen and the washer reservoir using
clean washer fluid, a mild detergent, or a non-abra-
sive cleaner. Flush foreign material from the washer
system plumbing by first disconnecting the washer
hoses from the washer nozzles, then running the
washer pump/motor to run clean washer fluid or
water through the system. Plugged or restricted
washer nozzles should be carefully back-flushed
using compressed air. If the washer nozzle obstruc-
tion cannot be cleared, replace the washer nozzle.
CAUTION: Never introduce petroleum-based clean-
ers, solvents, or contaminants into the washer sys-
tem. These products can rapidly deteriorate the
rubber seals and hoses of the washer system, as
well as the rubber squeegees of the wiper blades.
CAUTION: Never use compressed air to flush the
washer system plumbing. Compressed air pres-
sures are too great for the washer system plumbing
components and will result in further system dam-
age. Never use sharp instruments to clear a
plugged washer nozzle or damage to the nozzle ori-
fice and improper nozzle spray patterns will result.
INSPECTION - FRONT WIPER & WASHER
SYSTEM
FRONT WIPER SYSTEM
The front wiper blades and wiper arms should be
inspected periodically, not just when wiper perfor-
mance problems are experienced. This inspection
should include the following points:
(1) Inspect the wiper arms for any indications of
damage, or contamination. If the wiper arms are con-
taminated with any foreign material, clean them as
required. (Refer to 8 - ELECTRICAL/FRONT WIP-
ERS/WASHERS - CLEANING). If a wiper arm is
damaged or corrosion is evident, replace the wiper
arm with a new unit. Do not attempt to repair a
wiper arm that is damaged or corroded.
(2) Carefully lift the wiper blade off of the glass.
Note the action of the wiper arm hinge. The wiper
arm should pivot freely at the hinge, but with no lat-
eral looseness evident. If there is any binding evident
in the wiper arm hinge, or there is evident lateral
play in the wiper arm hinge, replace the wiper arm.
KJFRONT WIPERS/WASHERS 8R - 7
FRONT WIPERS/WASHERS (Continued)
Page 710 of 1803

OPERATION
The front check valve provides more than one func-
tion in this application. It serves as a wye connector
fitting between the cowl grille panel and washer noz-
zle sections of the front washer supply hose. It also
prevents washer fluid from draining out of the front
washer supply hoses back to the washer reservoir.
This drain-back would result in a lengthy delay when
the front washer switch is actuated until washer
fluid was dispensed through the front washer noz-
zles, because the washer pump would have to refill
the front washer plumbing from the reservoir to the
nozzles. Finally, the front check valve prevents
washer fluid from siphoning through the front
washer nozzles after the front washer system is
turned Off.
Within the check valve body, a small check valve is
held in place against a seat by a small coiled spring
to restrict flow through the unit until the valve is
unseated by a predetermined inlet fluid pressure.
When the washer pump pressurizes and pumps
washer fluid from the reservoir through the front
washer plumbing, the fluid pressure overrides the
spring pressure applied to the check valve and
unseats the valve, allowing washer fluid to flow
toward the front washer nozzles. When the washer
pump stops operating, spring pressure seats the
check valve and fluid flow in either direction within
the front washer plumbing is prevented.
REMOVAL
(1) Unlatch and open the hood.
(2) Remove both front wiper arms from the wiper
pivots. (Refer to 8 - ELECTRICAL/WIPERS/WASH-
ERS - FRONT/FRONT WIPER ARM - REMOVAL).
(3) Remove the cowl plenum cover/grille panel
from over the cowl plenum. (Refer to 23 - BODY/EX-
TERIOR/COWL GRILLE - REMOVAL).
(4) From the underside of the cowl plenum cover/
grille panel, disconnect the cowl plenum and washer
nozzle hoses from the three barbed nipples of the
front check valve (Fig. 4).
(5) Remove the front check valve from the under-
side of the cowl plenum cover/grille panel.
INSTALLATION
(1) Position the front check valve to the underside
of the cowl plenum cover/grille panel (Fig. 4). Be cer-
tain that the flow direction arrow molded into the
front check valve body is oriented towards the front
washer nozzles.
(2) From the underside of the cowl plenum cover/
grille panel, reconnect the cowl plenum and washer
nozzle hoses to the three barbed nipples of the front
check valve.
(3) Reinstall the cowl plenum cover/grille panel
over the cowl plenum. (Refer to 23 - BODY/EXTERI-
OR/COWL GRILLE - INSTALLATION).
(4) Reinstall both front wiper arms onto the wiper
pivots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARM - INSTALLATION).
(5) Close and latch the hood.
Fig. 3 Front Check Valve
1 - INLET NIPPLE
2 - FRONT CHECK VALVE
3 - OUTLET NIPPLE (2)
4 - FLOW DIRECTION ARROW
Fig. 4 Front Check Valve Remove/Install
1 - WASHER NOZZLE HOSE (RIGHT)
2 - FRONT CHECK VALVE
3 - COWL PLENUM WASHER HOSE
4 - ROUTING CLIP
5 - COWL GRILLE COVER (UNDERSIDE)
6 - WASHER NOZZLE HOSE (LEFT)
KJFRONT WIPERS/WASHERS 8R - 9
FRONT CHECK VALVE (Continued)
Page 733 of 1803

rear wiper on driver circuit between the rear wiper
module and the multi-function switch as required.
REAR WASHER SYSTEM
The diagnosis found here addresses an electrically
inoperative rear washer system. If the washer pump/
motor operates, but no washer fluid is emitted from
the rear washer nozzle, be certain to check the fluid
level in the reservoir. Also inspect the rear washer
system components as required. (Refer to 8 - ELEC-
TRICAL/REAR WIPERS/WASHERS - INSPECTION).
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Turn the ignition switch to the On position.
Turn the control ring on the right (wiper) control
stalk of the multi-function switch to the On position.
Check whether the rear wiper system is operating. If
OK, go to Step 2. If not OK, test and repair the rear
wiper system before continuing with these tests.
Refer to REAR WIPER SYSTEM .
(2) Pull the right (wiper) control stalk of the multi-
function switch toward the steering wheel. Check
whether the front washer system is operating. If OK,
test the multi-function switch. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/MULTI-
FUNCTION SWITCH - DIAGNOSIS AND
TESTING). If the multi-function switch tests OK, go
to Step 3. If the multi-function switch does not test
OK, replace the faulty switch.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the headlamp and dash wire harness con-
nector for the washer pump/motor unit from the
pump/motor unit connector receptacle. Check for con-
tinuity between the washer pump driver circuit cav-ity of the headlamp and dash wire harness connector
for the washer pump/motor unit and a good ground.
There should be no continuity. If OK, go to Step 4. If
not OK, repair the shorted washer pump driver cir-
cuit between the washer pump/motor unit and the
multi-function switch as required.
(4) Check for continuity between the washer pump
driver circuit cavities of the headlamp and dash wire
harness connector for the washer pump/motor unit
and the instrument panel wire harness connector for
the multi-function switch (Connector C-2). There
should be continuity. If OK, go to Step 5. If not OK,
repair the open washer pump driver circuit between
the washer pump/motor unit and the multi-function
switch as required.
(5) Check for continuity between the washer pump
sense circuit cavity of the headlamp and dash wire
harness connector for the washer pump/motor unit
and a good ground. There should be no continuity. If
OK, go to Step 6. If not OK, repair the shorted
washer pump sense circuit between the washer
pump/motor unit and the multi-function switch as
required.
(6) Check for continuity between the washer pump
sense circuit cavities of the headlamp and dash wire
harness connector for the washer pump/motor unit
and the instrument panel wire harness connector for
the multi-function switch (Connector C-2). There
should be continuity. If OK, replace the faulty washer
pump/motor unit. If not OK, repair the open washer
pump sense circuit between the washer pump/motor
unit and the multi-function switch as required.
CLEANING - REAR WIPER & WASHER SYSTEM
REAR WIPER SYSTEM
The squeegee of a wiper blade exposed to the ele-
ments for a long time tends to lose its wiping effec-
tiveness. Periodic cleaning of the squeegee is
suggested to remove any deposits of salt or road film.
The wiper blade, arm, and rear flip-up glass should
only be cleaned using a sponge or soft cloth and
windshield washer fluid, a mild detergent, or a non-
abrasive cleaner. If the wiper blade continues to
leave streaks, smears, hazing, or beading on the
glass after thorough cleaning of the squeegees and
the glass, the entire wiper blade assembly must be
replaced.
CAUTION: Protect the rubber squeegee of the wiper
blade from any petroleum-based cleaners, solvents,
or contaminants. These products can rapidly deteri-
orate the rubber squeegee.
8R - 32 REAR WIPERS/WASHERSKJ
REAR WIPERS/WASHERS (Continued)
Page 1466 of 1803

BODY
TABLE OF CONTENTS
page page
BODY
WARNING
SAFETY PRECAUTIONS AND WARNINGS . . . 1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - WATER LEAKS . 2
DIAGNOSIS AND TESTING - WIND NOISE . . . 3
STANDARD PROCEDURE
STANDARD PROCEDURE - BODY
LUBRICATION.........................3
STANDARD PROCEDURE - HEAT STAKING . . 3
SPECIFICATIONS........................4
SPECIAL TOOLS
BODY...............................5BODY STRUCTURE.......................6
HOOD................................119
DOOR - FRONT........................121
DOORS - REAR........................128
SWING GATE..........................135
EXTERIOR............................140
INSTRUMENT PANEL....................147
INTERIOR.............................156
PAINT................................162
SEATS...............................164
STATIONARY GLASS....................172
SUNROOF.............................175
WEATHERSTRIP/SEALS..................185
BODY
WARNING
SAFETY PRECAUTIONS AND WARNINGS
WARNING: EYE PROTECTION SHOULD BE USED
WHEN SERVICING GLASS COMPONENTS. PER-
SONAL INJURY CAN RESULT.
²USE A OSHA APPROVED BREATHING FILTER
WHEN SPRAYING PAINT OR SOLVENTS IN A CON-
FINED AREA. PERSONAL INJURY CAN RESULT.
²AVOID PROLONGED SKIN CONTACT WITH
PETROLEUM OR ALCOHOL±BASED CLEANING
SOLVENTS. PERSONAL INJURY CAN RESULT.
²DO NOT STAND UNDER A HOISTED VEHICLE
THAT IS NOT PROPERLY SUPPORTED ON SAFETY
STANDS. PERSONAL INJURY CAN RESULT.
CAUTION: When holes must be drilled or punched
in an inner body panel, verify depth of space to the
outer body panel, electrical wiring, or other compo-
nents. Damage to vehicle can result.
²Do not weld exterior panels unless combustible
material on the interior of vehicle is removed from
the repair area. Fire or hazardous conditions, can
result.
²Always have a fire extinguisher ready for use
when welding.
²Disconnect the negative (-) cable clamp from
the battery when servicing electrical components
that are live when the ignition is OFF. Damage to
electrical system can result.²Do not use abrasive chemicals or compounds
on painted surfaces. Damage to finish can result.
²Do not use harsh alkaline based cleaning sol-
vents on painted or upholstered surfaces. Damage
to finish or color can result.
²Do not hammer or pound on plastic trim panel
when servicing interior trim. Plastic panels can
break.
DaimlerChrysler Corporation uses many different
types of push-in fasteners to secure the interior and
exterior trim to the body. Most of these fasteners can
be reused to assemble the trim during various repair
procedures. At times, a push-in fastener cannot be
removed without damaging the fastener or the com-
ponent it is holding. If it is not possible to remove a
fastener without damaging a component or body, cut
or break the fastener and use a new one when
installing the component. Never pry or pound on a
plastic or pressed-board trim component. Using a
suitable fork-type prying device, pry the fastener
from the retaining hole behind the component being
removed. When installing, verify fastener alignment
with the retaining hole by hand. Push directly on or
over the fastener until it seats. Apply a low-force pull
to the panel to verify that it is secure.
When it is necessary to remove components to ser-
vice another, it should not be necessary to apply
excessive force or bend a component to remove it.
Before damaging a trim component, verify hidden
fasteners or captured edges holding the component in
place.
KJBODY 23 - 1
Page 1642 of 1803

Before beginning diagnosis for wind noise or water
leaks, verify that the problem was not caused by
releasing the control switch before the sunroof was
fully closed. The sunroof module has a water-man-agement system. If however, the sunroof glass is in a
partial closed position, high pressure water may be
forced beyond the water management system bound-
aries and onto the headlining.
SUNROOF DIAGNOSIS CHART
SYMPTOM POSSIBLE CAUSE
Sunroof motor inoperative. Faulty control switch.
Faulty circuit ground between sunroof electronics module,
control switch, and body harness.
Faulty power circuit between sunroof electronics module,
control switch, and body harness.
Faulty drive motor.
Faulty electronics module.
Faulty drive motor electrical connector.
Audible whine when switch is depressed,
sunroof does not operate.Faulty drive motor.
Binding cable.
Audible clicking or ratcheting when switch is
pressed, sunroof does not operate.Broken or worn drive cable.
Worn drive motor gear.
Mechanisms not synchronized.
Sunroof vents and opens, but does not close. Binding cable.
Faulty circuit.
Faulty control switch.
Faulty electronic module.
Faulty drive motor.
Sunroof vents, but does not open. Binding cable or mechanism.
Faulty circuit.
Faulty switch.
Faulty electronic module.
Sunroof does not vent Binding cable or mechanism.
Faulty circuit.
Faulty control switch.
Faulty sunroof electronic module.
Sunroof water leak. Drain tubes clogged or kinked or disconnected from the
sunroof.
Glass panel improperly adjusted.
Faulty glass panel seal.
Gurgling sound from sunroof Low spot in drain hose routing, allowing water to stand.
Wind noise from sunroof. Front of glass panel too high or rear too low.
Wind deflector not deploying.
Glass not centered in opening.
Faulty glass panel seal.
Rattles from open sunroof while driving Loose or broken attaching hardware.
Worn or broken mechanism.
KJSUNROOF 23 - 177
SUNROOF (Continued)
Page 1694 of 1803

used to charge the refrigerant system with R-134a
refrigerant. Refer to the operating instructions sup-
plied by the equipment manufacturer for proper care
and use of this equipment.
SPECIFICATIONS - CHARGE CAPACITY
The R-134a refrigerant system charge capacity for
this vehicle is 0.737 kilograms (1.63 pounds).
A/C COMPRESSOR
DESCRIPTION
DESCRIPTION
The air conditioning system uses a Sanden
PXF-18, reciprocating swash plate-type compressor
on all models. This compressor has a fixed displace-
ment of 180 cubic centimeters (10.984 cubic inches),
and has both the suction and discharge ports located
on the cylinder head. A label identifying the use of
R-134a refrigerant is located on the compressor.
DESCRIPTION - HIGH PRESSURE RELIEF
VALVE
A high pressure relief valve is located on the com-
pressor cylinder head, which is on the rear of the
compressor. This mechanical valve is designed to
vent refrigerant from the system to protect against
damage to the compressor and other system compo-
nents, caused by condenser air flow restriction or an
overcharge of refrigerant.
OPERATION
OPERATION
The compressor is driven by the engine through an
electric clutch, drive rotor and belt arrangement. The
compressor is lubricated by refrigerant oil that is cir-
culated throughout the refrigerant system with the
refrigerant.
The compressor draws in low-pressure refrigerant
vapor from the evaporator through its suction port. It
then compresses the refrigerant into a high-pressure,
high-temperature refrigerant vapor, which is then
pumped to the condenser through the compressor dis-
charge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
replaced. The compressor clutch, pulley and clutch
coil are available for service.
OPERATION - HIGH PRESSURE RELIEF VALVE
The high pressure relief valve vents the system
when a discharge pressure of 3445 to 4135 kPa (500
to 600 psi) or above is reached. The valve closes
when a minimum discharge pressure of 2756 kPa
(400 psi) is reached.
The high pressure relief valve vents only enough
refrigerant to reduce the system pressure, and then
re-seats itself. The majority of the refrigerant is con-
served in the system. If the valve vents refrigerant, it
does not mean that the valve is faulty.
The high pressure relief valve is a factory-cali-
brated unit. The valve cannot be adjusted or
repaired, and must not be removed or otherwise dis-
turbed. The valve is only serviced as a part of the
compressor assembly.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
NOISE
When investigating an air conditioning related
noise, you must first know the conditions under
which the noise occurs. These conditions include:
weather, vehicle speed, transmission in gear or neu-
tral, engine speed, engine temperature, and any
other special conditions. Noises that develop during
air conditioning operation can often be misleading.
For example: What sounds like a failed front bearing
or connecting rod, may be caused by loose bolts, nuts,
mounting brackets, or a loose compressor clutch
assembly.
Drive belts are speed sensitive. At different engine
speeds and depending upon belt tension, belts can
develop noises that are mistaken for a compressor
noise. Improper belt tension can cause a misleading
noise when the compressor clutch is engaged, which
may not occur when the compressor clutch is disen-
gaged. Check the serpentine drive belt condition and
tension as described in Cooling before beginning this
procedure.
(1) Select a quiet area for testing. Duplicate the
complaint conditions as much as possible. Switch the
compressor on and off several times to clearly iden-
tify the compressor noise. Listen to the compressor
while the clutch is engaged and disengaged. Probe
the compressor with an engine stethoscope or a long
screwdriver with the handle held to your ear to bet-
ter localize the source of the noise.
(2) Loosen all of the compressor mounting hard-
ware and retighten. Tighten the compressor clutch
mounting nut. Be certain that the clutch coil is
mounted securely to the compressor, and that the
clutch plate and rotor are properly aligned and have
the correct air gap. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH - INSTALLATION)
24 - 42 PLUMBINGKJ
PLUMBING (Continued)
Page 1734 of 1803

The pump contains a 3 port solenoid, a pump that
contains a switch, a spring loaded canister vent valve
seal, 2 check valves and a spring/diaphragm.
OPERATION
Immediately after a cold start, engine temperature
between 40ÉF and 86ÉF, the 3 port solenoid is briefly
energized. This initializes the pump by drawing air
into the pump cavity and also closes the vent seal.
During non-test test conditions, the vent seal is held
open by the pump diaphragm assembly which pushes
it open at the full travel position. The vent seal will
remain closed while the pump is cycling. This is due
to the operation of the 3 port solenoid which prevents
the diaphragm assembly from reaching full travel.
After the brief initialization period, the solenoid is
de-energized, allowing atmospheric pressure to enter
the pump cavity. This permits the spring to drive the
diaphragm which forces air out of the pump cavity
and into the vent system. When the solenoid is ener-
gized and de-energized, the cycle is repeated creating
flow in typical diaphragm pump fashion. The pump
is controlled in 2 modes:
PUMP MODE:The pump is cycled at a fixed rate
to achieve a rapid pressure build in order to shorten
the overall test time.
TEST MODE:The solenoid is energized with a
fixed duration pulse. Subsequent fixed pulses occur
when the diaphragm reaches the switch closure
point.
The spring in the pump is set so that the system
will achieve an equalized pressure of about 7.5 inches
of water.
When the pump starts, the cycle rate is quite high.
As the system becomes pressurized pump rate drops.
If there is no leak the pump will quit. If there is a
leak, the test is terminated at the end of the test
mode.
If there is no leak, the purge monitor is run. If the
cycle rate increases due to the flow through the
purge system, the test is passed and the diagnostic is
complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.
REMOVAL
The Leak Detection Pump (LDP) is attached (bolt-
ed) to the front of the fuel tank (Fig. 3). The LDP
fresh air filter is located on the end of a hose. This
hose is attached to the fuel fill tube assembly below
and near the fuel fill opening (Fig. 1). The LDP and
LDP filter are typically replaced (serviced) as one
unit.
(1) Raise vehicle.(2) Carefully remove two 3/4º vent hoses at sides
of LDP.
(3) Carefully remove other vapor/vacuum hoses
from LDP.
(4) Place a hydraulic jack under fuel tank.
(5) Loosen 2 fuel tank strap mounting bolts at
front of tank about 10 turns.
(6) Lower front of fuel tank about 1/2º.
(7) Remove 2 LDP mounting nuts (Fig. 3) and
lower LDP slightly to gain access to electrical connec-
tor (Fig. 4).
(8) Disconnect electrical connector at LDP. To dis-
connect: Slide red colored tab upward. Push on black
colored tab while removing connector.
(9) Remove LDP from vehicle.
INSTALLATION
The Leak Detection Pump (LDP) is attached (bolt-
ed) to the front of the fuel tank. The LDP filter is
located on the end of a hose. This hose is attached to
the fuel fill tube assembly below and near the fuel
fill opening. The LDP and LDP filter are replaced
(serviced) as one unit.
(1) Install electrical connector to LDP. Push red
colored tab downward to lock connector to LDP.
(2) Position LDP and LDP bracket to fuel tank
mounting studs and install 2 nuts. Tighten nuts to 1
N´m (11 in. lbs.) torque.
(3) Raise fuel tank to body and tighten 2 strap
bolts to 61 N´m (45 ft. lbs.) torque.
Fig. 3 LDP LOCATION / MOUNTING
1 - LDP
2 - FLOW MANAGEMENT VALVE
3 - MOUNTING NUTS
4 - FRONT OF FUEL TANK
25 - 28 EVAPORATIVE EMISSIONSKJ
LEAK DETECTION PUMP (Continued)
Page 1739 of 1803

VACUUM LINES
DESCRIPTION
A vacuum schematic for emission related items can
be found on the VECI label. Refer to Vehicle Emis-
sion Control Information (VECI) Label for label loca-
tion.
VAPOR CANISTER
DESCRIPTION
A maintenance free, EVAP canister is used on all
gasoline powered models. The EVAP canister is
located near the left/front corner of the fuel tank.
OPERATION
The EVAP canister is filled with granules of an
activated carbon mixture. Fuel vapors entering the
EVAP canister are absorbed by the charcoal granules.
The canister serves two functions: as a temporary
fuel vapor storage point while refueling the vehicle
for the ORVR system, as a temporary vapor storage
point while the engine is running.
Fuel tank pressure vents into the EVAP canister.
Fuel vapors are temporarily held in the canister until
they can be drawn into the intake manifold. The duty
cycle EVAP canister purge solenoid allows the EVAP
canister to be purged at predetermined times and at
certain engine operating conditions.
Refer to ORVR for additional information.
REMOVAL
The EVAP canister is located near front of fuel
tank and next to left/rear spring. (Fig. 13).
(1) Raise vehicle.
(2) Disconnect vacuum hoses/lines at EVAP canis-
ter. Note location of lines before removal.
(3) Remove EVAP canister and mounting bracket
assembly from body (2 bolts).
(4) Remove canister-to-mounting bracket bolt.
(5) Slide 2 canister mounting pins from mounting
bracket (Fig. 14).
INSTALLATION
(1) Slide 2 canister mounting pins into mounting
bracket (Fig. 14).
(2) Install canister-to-mounting bracket bolt.
(3) Position canister and bracket assembly to body.
(4) Install 2 mounting bracket bolts. Tighten to 47
N´m (35 ft. lbs.) torque.
(5) Connect vacuum hoses/lines at EVAP canister.
(6) Lower vehicle.
Fig. 13 EVAP CANISTER LOCATION
1 - LEFT/REAR SPRING
2 - EVAP CANISTER
3 - MOUNTING BRACKET
4 - BRACKET BOLTS
5 - VACUUM LINES
Fig. 14 EVAP CANISTER MOUNTING PINS
1 - MOUNTING PINS
2 - MOUNTING BRACKET
3 - EVAP CANISTER
KJEVAPORATIVE EMISSIONS 25 - 33