Cooling JEEP LIBERTY 2002 KJ / 1.G Owners Manual
[x] Cancel search | Manufacturer: JEEP, Model Year: 2002, Model line: LIBERTY, Model: JEEP LIBERTY 2002 KJ / 1.GPages: 1803, PDF Size: 62.3 MB
Page 1351 of 1803

CAUTION: Do not use an impact wrench for tighten-
ing camshaft sprocket bolt. Damage to the timing
locating pin can occur. Hand tighten using a
wrench ONLY.
(2) Install camshaft sprockets, and camshaft target
ring. Hold sprockets with Special Tool 6848 and
tighten center bolt to 101 N´m (75 ft. lbs.).
(3) Install timing belt idler pulley and tighten
mounting bolt to 61 N´m (45 ft. lbs.).
(4) Install timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
(5) Install accessory drive bracket (Fig. 93).
(6) Install front covers.
FRONT COVER
(1) Install timing belt front covers (Fig. 94).
Tighten fasteners to 7 N´m (60 in. lbs.).
(2) Install generator drive belt tensioner. (Refer to
7 - COOLING/ACCESSORY DRIVE/BELT TEN-
SIONERS - INSTALLATION)
(3) Install crankshaft vibration damper. (Refer to 9
- ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION)
Fig. 92 TIMING BELT REAR COVER FASTENERS
1 - OUTER COVER TO REAR COVER FASTENERS (3)
2 - REAR COVER TO CYLINDER HEAD FASTENERS
3 - OUTER COVER TO REAR COVER FASTENERS (3)
4 - INNER COVER TO BLOCK FASTENERS
Fig. 93 ACCESSORY DRIVE BRACKET
1- UPPER TIMING BELT COVER
2- LOWER TIMING BELT COVER
3- BELT TENSIONER
4- ACCESSORY DRIVE BRACKET
Fig. 94 TIMING BELT COVERS
1- UPPER TIMING BELT COVER
2- REAR TIMING BELT COVER
3- LOWER TIMING BELT COVER
4- ACCESSORY DRIVE BRACKET NOT SHOWN
9s - 54 ENGINEKJ
TIMING BELT COVER(S) (Continued)
Page 1352 of 1803

TIMING BELT AND
SPROCKET(S)
REMOVAL
REMOVAL - TIMING BELT
(1) Remove air cleaner upper cover, housing, and
clean air tube.
(2) Raise vehicle on hoist.
(3) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELT TENSION-
ERS - REMOVAL)
(4) Remove crankshaft vibration damper. (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL)
(5) Remove air conditioner/generator belt tensioner
and pulley assembly. (Refer to 7 - COOLING/ACCES-
SORY DRIVE/BELT TENSIONERS - REMOVAL)
(6) Remove timing belt lower front cover bolts and
remove cover. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - REMOVAL)
(7) Lower vehicle.
(8) Remove bolts attaching timing belt upper front
cover and remove cover. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- REMOVAL)
CAUTION: When aligning crankshaft and camshaft
timing marks always rotate engine from crankshaft.
Camshaft should not be rotated after timing belt is
removed. Damage to valve components may occur.
Always align timing marks before removing timing
belt.
(9) Before the removal of the timing belt, rotate
crankshaft until the TDC mark on oil pump housing
aligns with the TDC mark on crankshaft sprocket
(trailing edge of sprocket tooth) (Fig. 95).
NOTE: The crankshaft sprocket TDC mark is
located on the trailing edge of the sprocket tooth.
Failure to align trailing edge of sprocket tooth to
TDC mark on oil pump housing will cause the cam-
shaft timing marks to be misaligned.
(10) Install 6 mm Allen wrench into belt tensioner.
Before rotating the tensioner, insert the long end of a
1/8º or 3 mm Allen wrench into the pin hole on the
front of the tensioner (Fig. 96). While rotating the
tensioner counterclockwise, push in lightly on the
1/8º or 3 mm Allen wrench, until it slides into the
locking hole.
(11) Remove timing belt.
REMOVAL - CRANKSHAFT SPROCKET
(1) Disconnect negative battery cable.
(2) Remove timing belt (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL).
(3) Remove crankshaft sprocket using Special
Tools 6793 and insert C-4685-C2 (Fig. 97).
CLEANING
Do Not attempt to clean a timing belt. If contami-
nation from oil, grease, or coolants have occurred, the
timing belt should be replaced.
Clean all sprockets using a suitable solvent. Clean
all sprocket grooves of any debris.
Fig. 95 Crankshaft and Camshaft Timing
1 - CAMSHAFT TIMING MARKS
2 - CRANKSHAFT TDC MARKS
3 - TRAILING EDGE OF SPROCKET TOOTH
KJENGINE9s-55
Page 1355 of 1803

(8) Check if the spring tang is within the tolerance
window (Fig. 103). If the spring tang is within the
tolerance window, the installation process is complete
and nothing further is required. If the spring tang is
not within the tolerance window, repeat Steps 5
through 7.
(9) Install timing belt front covers and bolts.
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT / CHAIN COVER(S) - INSTALLATION)
(10) Install air conditioning/generator belt ten-
sioner and pulley. (Refer to 7 - COOLING/ACCES-
SORY DRIVE/BELT TENSIONERS -
INSTALLATION)
(11) Install crankshaft vibration damper. (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - INSTALLATION)
(12) Install accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION)
(13) Install drive belt splash shield.
(14) Install air cleaner housing, upper cover, and
clean air tube.
Fig. 101 Timing Belt Tension Adjustment
1 - ALIGN SETTING NOTCH WITH SPRING TANG
2 - TOP PLATE
3 - 6mm ALLEN WRENCH
4 - LOCK NUT
5 - SETTING NOTCH
6 - SPRING TANG
Fig. 102 Crankshaft and Camshaft Timing
1 - CAMSHAFT TIMING MARKS
2 - CRANKSHAFT TDC MARKS
3 - TRAILING EDGE OF SPROCKET TOOTH
Fig. 103 Timing Belt Tension Verification
1 - SPRING TANG
2 - TOLERANCE WINDOW
9s - 58 ENGINEKJ
TIMING BELT AND SPROCKET(S) (Continued)
Page 1406 of 1803

(14) If fuel injectors are to be removed, refer to
Fuel Injector Removal/Installation.
INSTALLATION
2.4L Engine
(1) If fuel injectors are to be installed, refer to Fuel
Injector Removal/Installation.
(2) Clean out fuel injector machined bores in
intake manifold.
(3) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(4) Position fuel rail/fuel injector assembly to
machined injector openings in intake manifold.
(5) Guide each injector into cylinder head. Be care-
ful not to tear injector o-rings.
(6) Push fuel rail down until fuel injectors have
bottomed on shoulders.
(7) Install 2 fuel rail mounting bolts and tighten.
Refer to torque specifications.
(8) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 37). Push con-
nector onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injec-
tor by lightly tugging on connector.
(9) Snap 2 injection wiring harness clips (Fig. 35)
into brackets.
(10) Connect 2 main engine harness connectors at
rear of intake manifold (Fig. 34).
(11) Tighten 5 intake manifold mounting bolts.
Refer to Engine Torque Specifications.
(12) Install PCV valve and hose.
(13) Install thermostat and radiator hose. Fill with
coolant. Refer to Cooling.
(14) Connect necessary vacuum lines to throttle
body.
(15) Connect fuel line latch clip and fuel line to
fuel rail. Refer to Quick-Connect Fittings.
(16) Install air duct to throttle body.
(17) Connect battery cable to battery.
(18) Start engine and check for leaks.
3.7L Engine
(1) If fuel injectors are to be installed, refer to Fuel
Injector Removal/Installation.
(2) Clean out fuel injector machined bores in
intake manifold.
(3) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(4) Position fuel rail/fuel injector assembly to
machined injector openings in cylinder head.
(5) Guide each injector into cylinder head. Be care-
ful not to tear injector o-rings.
(6) Pushrightside of fuel rail down until fuel
injectors have bottomed on cylinder head shoulder.Pushleftfuel rail down until injectors have bot-
tomed on cylinder head shoulder.
(7) Install 4 fuel rail mounting bolts and tighten.
Refer to torque specifications.
(8) Install 6 ignition coils. Refer to Ignition Coil
Removal/Installation.
(9) Connect electrical connectors to throttle body.
(10) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 37). Push con-
nector onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injec-
tor by lightly tugging on connector.
(11) Connect necessary vacuum lines to throttle
body.
(12) Connect fuel line latch clip and fuel line to
fuel rail. Refer to Quick-Connect Fittings.
(13) Install air box to throttle body.
(14) Install air duct to air box.
(15) Connect battery cable to battery.
(16) Start engine and check for leaks.
FUEL TANK
DESCRIPTION
The fuel tank is constructed of a plastic material.
Its main functions are for fuel storage and for place-
ment of the fuel pump module, and certain ORVR
components.
OPERATION
All models pass a full 360 degree rollover test
without fuel leakage. To accomplish this, fuel and
vapor flow controls are required for all fuel tank con-
nections.
A check (control) valve is mounted into the top sec-
tion of the 2±piece fuel pump module. Refer to Fuel
Tank Check Valve for additional information.
An evaporation control system is connected to the
fuel tank to reduce emissions of fuel vapors into the
atmosphere. When fuel evaporates from the fuel
tank, vapors pass through vent hoses or tubes to a
charcoal canister where they are temporarily held.
When the engine is running, the vapors are drawn
into the intake manifold. Certain models are also
equipped with a self-diagnosing system using a Leak
Detection Pump (LDP) and/or an ORVR system.
Refer to Emission Control System for additional
information.
14 - 24 FUEL DELIVERYKJ
FUEL RAIL (Continued)
Page 1448 of 1803

NOTE: Power steering pumps have different pres-
sure rates and are not interchangeable with other
pumps.
STANDARD PROCEDURE - POWER STEERING
PUMP - INITIAL OPERATION
WARNING: THE FLUID LEVEL SHOULD BE
CHECKED WITH ENGINE OFF TO PREVENT INJURY
FROM MOVING COMPONENTS.
CAUTION: Use MOPAR Power Steering Fluid or
equivalent. Do not use automatic transmission fluid
and do not overfill.
Wipe filler cap clean, then check the fluid level.
The dipstick should indicateCOLDwhen the fluid is
at normal ambient temperature.
(1) Fill the pump fluid reservoir to the proper level
and let the fluid settle for at least two minutes.
(2) Raise the front wheels off the ground.
(3) Slowly turn the steering wheel right and left,
lightly contacting the wheel stops at least 20 times.
(4) Check the fluid level add if necessary.
(5) Lower the vehicle, start the engine and turn
the steering wheel slowly from lock to lock.
(6) Stop the engine and check the fluid level and
refill as required.
CAUTION: Do not run a vehicle with foamy fluid for
an extended period. This may cause pump damage.
(7) If the fluid is extremely foamy or milky look-
ing, allow the vehicle to stand a few minutes and
repeat the procedure.
(8) Add fluid if necessary. Repeat the above proce-
dure until the fluid level remains constant after run-
ning the engine.
REMOVAL
REMOVAL - 3.7L
(1) Siphon out as much power steering fluid as
possible.
(2) Remove the radiator cross member (Refer to 23
- BODY/EXTERIOR/RADIATOR CROSSMEMBER -
REMOVAL).
(3) Remove the engine cooling fan (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(4) Remove the fan shroud
(5) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(6) Remove the power steering high pressure hose
at the pump.
(7) Remove the return hose at the pump.
(8) Remove the three bolts securing the pump to
the bracket thru the holes in the pulley. (Fig. 3)
(9) Remove the pump from the vehicle.
REMOVAL - 2.4L
CAUTION: On vehicles equipped with the 2.4L, Do
not reuse the old power steering pump pulley it is
not intended for reuse. A new pulley must be
installed if removed.
(1) Siphon out as much power steering fluid as
possible.
(2) Remove the serpentine drive belt.
(3) Remove the power steering high pressure hose
at the pump using care not to remove the flow con-
trol valve.
(4) Remove the return hose at the pump.
Fig. 2 FLUID RESERVOIR - 2.4L
Fig. 3 POWER STEERING PUMP - 3.7L
1 - MOUNTING BOLTS
2 - RESERVOIR
3 - STEEL PULLEY
19 - 18 PUMPKJ
PUMP (Continued)
Page 1449 of 1803

(5) Remove the two nuts securing the wire loom
behind the pump bracket.
(6) Remove the three bolts securing the pump to
the bracket thru the holes in the pulley. (Fig. 4)
(7) Remove the pump from the vehicle.
INSTALLATION
INSTALLATION - 3.7L
(1) Install the pump to the vehicle.(2) Install the three bolts securing the pump to the
engine. (Fig. 3) Tighten the bolts to 47 N´m (35
ft.lbs.).
(3) Install the power steering hoses.
(4) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(5) Install the fan shroud
(6) Install the engine cooling fan (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
(7) Install the radiator crossmember (Refer to 23 -
BODY/EXTERIOR/RADIATOR CROSSMEMBER -
INSTALLATION).
(8) Refill the power steering fluid and check for
leaks (Refer to 19 - STEERING/PUMP - STANDARD
PROCEDURE).
INSTALLATION - 2.4L
(1) Install the pump to the vehicle.
(2) Install the three bolts securing the pump to the
engine. (Fig. 4) Tighten the bolts to 47 N´m (35
ft.lbs.).
(3) Install the two nuts securing the wire loom to
the pump bracket.
(4) Install the power steering pressure and supply
hoses.
(5) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(6) Refill the power steering fluid and check for
leaks (Refer to 19 - STEERING/PUMP - STANDARD
PROCEDURE).
SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Power Steering Pump
Bracket to Pump28 21 Ð
Power Steering Pump
Bracket to Engine47 35 Ð
Power Steering Pump
Flow Control Valve75 55 Ð
Power Steering Pump
Pressure Line28 21 Ð
Power Steering Pump
Pressure Line Bracket12 9 105
Fig. 4 POWER STEERING PUMP - 2.4L
1 - MOUNTING BOLTS
2 - PULLEY
KJPUMP 19 - 19
PUMP (Continued)
Page 1451 of 1803

HOSES
REMOVAL
REMOVAL - PRESSURE HOSE
(1) Siphon the power steering fluid from the reser-
voir.
(2) Remove the radiator crossmember (Refer to 23
- BODY/EXTERIOR/RADIATOR CROSSMEMBER -
REMOVAL).
(3) Remove the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - REMOVAL).
(4) Remove the fan shroud.
(5) Remove the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - REMOV-
AL).
(6) Remove the pressure hose at the pump.
(7) Disconnect the pressure switch electrical con-
nector from the pressure hose.
(8) Remove the pressure hose from the gear.
(9) Remove the pressure hose mounting bracket
bolts from behind the headlamp assembly. (Fig. 6)
(10) Remove the pressure hose from the vehicle
and transfer power steering pressure switch if neces-
sary.
REMOVAL - RETURN HOSE (GEAR TO THE
COOLER)
(1) Siphon the power steering fluid from the reser-
voir.
(2) Remove the radiator crossmember (Refer to 23
- BODY/EXTERIOR/RADIATOR CROSSMEMBER -
REMOVAL).
(3) Remove the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - REMOVAL).(4) Remove the fan shroud.
(5) Remove the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - REMOV-
AL).
(6) Remove the return hose from the gear.
(7) Remove the return hose at the cooler.
(8) Remove the return hose mounting bracket bolts
from the front cradle. (Fig. 7)
(9) Remove the return hose from the vehicle.
REMOVAL - RETURN HOSE (RESERVOIR TO
THE COOLER)
(1) Siphon the power steering fluid from the reser-
voir.
(2) Remove the return hose from the pump reser-
voir.
(3) Remove the return hose at the cooler.
(4) Remove the return hose from the vehicle.
INSTALLATION
INSTALLATION - PRESSURE HOSE
(1) Install the pressure hose to the vehicle. (Fig. 8)
(2) Install the pressure hose mounting bracket
bolts behind the headlamp assembly. Tighten to to 12
N´m (9 ft.lbs.).
(3) Install the pressure hose to the gear. Tighten
the hose to28 N´m (21 ft.lbs.).
(4) Install the pressure switch electrical connector.
(5) Install the pressure hose at the pump. Tighten
the hose to28 N´m (21 ft.lbs.).
Fig. 6 MOUNTING BRACKET
1 - HIGH PRESSURE POWER STEERING HOSE
2 - MOUNTING BRACKET
Fig. 7 RETURN HOSE TO COOLER
1 - MOUNTING BRACKETS
2 - FLUID COOLER
3 - PRESSURE SWITCH
4 - RETURN HOSE
KJPUMP 19 - 21
Page 1452 of 1803

(6) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(7) Install the fan shroud.
(8) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(9) Install the radiator crossmember (Refer to 23 -
BODY/EXTERIOR/RADIATOR CROSSMEMBER -
INSTALLATION).
(10) Refill the power steering fluid (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
INSTALLATION - RETURN HOSE (GEAR TO THE
COOLER)
(1) Install the return hose to the vehicle. (Fig. 7)
(2) Install the return hose mounting bracket bolts
to the front cradle.
(3) Install the return hose at the cooler.
(4) Install the return hose at the gear 28 N´m (21
ft.lbs.).
(5) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(6) Install the fan shroud.
(7) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(8) Install the radiator crossmember (Refer to 23 -
BODY/EXTERIOR/RADIATOR CROSSMEMBER -
INSTALLATION).
(9) Refill the power steering fluid (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
INSTALLATION - RETURN HOSE (RESERVOIR
TO THE COOLER)
(1) Install the return hose to the vehicle.
(2) Install the return hose to the pump reservoir.
(3) Install the return hose at the cooler.
(4) Refill the power steering fluid (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
POWER STEERING PRESSURE
SWITCH
DESCRIPTION
A pressure sensing switch is used in the power
steering system. It is mounted on the high-pressure
steering hose. This switch will be used with both
2.4L and 3.7L engines.
OPERATION
The switch is used on both the 2.4L 4±cylinder and
3.7L V-6 engines.
The power steering pressure switch provides an
input to the Powertrain Control Module (PCM). This
input is provided during periods of high steering
pump load and low engine rpm; such as during park-
ing maneuvers. The PCM increases the idle speed
through the Idle Air Control (IAC) motor. This is
done to prevent the engine from stalling under the
increased load.
When steering pump pressure exceeds 3275 kPa
690 kPa (475 psi 100 psi), the Normally Closed
(NC) switch will open and the PCM will increase the
engine idle speed. This will prevent the engine from
stalling.
When pump pressure drops to approximately 1379
kPa (200 psi), the switch circuit will re-close and
engine idle speed will return to its previous setting.
REMOVAL
The power steering pressure switch is installed in
the power steering high-pressure hose (Fig. 9).
(1) Remove the high pressure power steering
hose(Refer to 19 - STEERING/PUMP/HOSES -
REMOVAL).
(2) Disconnect electrical connector from power
steering pressure switch.
(3) Place a small container or shop towel beneath
switch to collect any excess fluid.
(4) Remove switch. Use back-up wrench on power
steering line to prevent line bending.
INSTALLATION
(1) Install power steering switch into power steer-
ing line. (Fig. 9)
(2) Tighten to 9.6 N´m (85 in. lbs.) torque.
Fig. 8 HIGH PRESSURE HOSE ASSEMBLY
1 - HIGH PRESSURE POWER STEERING HOSE
2 - MOUNTING BRACKET
3 - POWER STEERING PRESURE SWITCH
19 - 22 PUMPKJ
HOSES (Continued)
Page 1653 of 1803

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - HEATER AND AIR
CONDITIONER........................1
DESCRIPTION - COOLING SYSTEM
REQUIREMENTS.......................1
DESCRIPTION - REFRIGERANT SYSTEM
SERVICE PORT........................2
OPERATION
OPERATION - HEATER AND AIR
CONDITIONER........................2
OPERATION - REFRIGERANT SYSTEM
SERVICE PORT........................2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE.......................2DIAGNOSIS AND TESTING - HEATER
PERFORMANCE.......................6
DIAGNOSIS AND TESTING - VACUUM
SYSTEM.............................6
STANDARD PROCEDURE - DIODE
REPLACEMENT.......................9
SPECIFICATIONS
A/C APPLICATION TABLE................9
SPECIFICATIONS.....................10
CONTROLS.............................11
DISTRIBUTION..........................29
PLUMBING.............................38
HEATING & AIR
CONDITIONING
DESCRIPTION
DESCRIPTION - HEATER AND AIR
CONDITIONER
All vehicles are equipped with a common HVAC
housing assembly (Fig. 1). The system combines air
conditioning, heating, and ventilating capabilities in
a single unit housing mounted under the instrument
panel. On heater-only systems, the evaporator coil is
omitted from the housing.
DESCRIPTION - COOLING SYSTEM
REQUIREMENTS
To maintain the performance level of the HVAC
system, the engine cooling system must be properly
maintained. The use of a bug screen is not recom-
mended. Any obstructions in front of the radiator or
condenser will reduce the performance of the air con-
ditioning and engine cooling systems.
The engine cooling system includes the heater core
and the heater hoses. Refer to Engine Cooling for
more information before the opening of, or attempt-
ing any service to the engine cooling system.
Fig. 1 Blend Door
1 - DEFROSTER DOOR
2- HEATER CORE
3- BLEND DOORS
4- BLOWER MOTOR HOUSING
5- EVAPORATOR (A/C ONLY)
6- LOWER HVAC CASE ASSEMBLY
KJHEATING & AIR CONDITIONING 24 - 1
Page 1657 of 1803

Pressure Diagnosis
Condition Possible Causes Correction
4. Faulty compressor. 4. See A/C Compressor in this group. Replace
the compressor, if required.
The low side pressure is
normal or slightly high, and
the high side pressure is too
high.1. Condenser air flow
restricted.1. Check the condenser for damaged fins, foreign
objects obstructing air flow through the condenser
fins, and missing or improperly installed air seals.
Refer to Cooling for more information on air
seals. Clean, repair, or replace components as
required.
2. Inoperative cooling fan. 2. Refer to Cooling for more information. Test the
cooling fan and replace, if required.
3. Refrigerant system
overcharged.3. See Plumbing/Standard Procedure -
Refrigerant System Charge in this group. Recover
the refrigerant from the refrigerant system.
Charge the refrigerant system to the proper level,
if required.
4. Air in the refrigerant
system.4. See Plumbing/Diagnosis and Testing -
Refrigerant System Leaks in this group. Test the
refrigerant system for leaks. Repair, evacuate and
charge the refrigerant system, if required.
5. Engine overheating. 5. Refer to Cooling for more information. Test the
cooling system and repair, if required.
The low side pressure is too
high, and the high side
pressure is too low.1. Accessory drive belt
slipping.1. Refer to Cooling for more information. Inspect
the accessory drive belt condition and tension.
Tighten or replace the accessory drive belt, if
required.
2. Fixed orifice tube not
installed.2. See A/C Orifice Tube in this group. Replace
the liquid line, if required.
3. Faulty compressor. 3. See A/C Compressor in this group. Replace
the compressor, if required.
The low side pressure is too
low, and the high side
pressure is too high.1. Restricted refrigerant flow
through the refrigerant lines.1. See Liquid, Suction, and Discharge Line in this
group. Inspect the refrigerant lines for kinks, tight
bends or improper routing. Correct the routing or
replace the refrigerant line, if required.
2. Restricted refrigerant flow
through the fixed orifice tube.2. See A/C Orifice Tube in this group. Replace
the liquid line, if required.
3. Restricted refrigerant flow
through the condenser.3. See A/C Condenser in this group. Replace the
restricted condenser, if required.
KJHEATING & AIR CONDITIONING 24 - 5
HEATING & AIR CONDITIONING (Continued)