2002 JEEP GRAND CHEROKEE connector

(7) Raise the vehicle on a hoist.
(8) Remove the front splash shield (if equipped).
(9) Remove the refrigerant line retaining fastener
from the compressor outlet fitting. Remove the line
and cap the compressor outlet opening to prevent
contamination of the system.
(10) Unclip and remove the discharge line from the
vehicle.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS GROUP BEFORE
PERFORMING THE FOLLOWING OPERATION.
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Remove the a/c high pressure transducer(Refer
to 24 - HEATING & AIR CONDITIONING/CON-
TROLS/A/C PRESSURE TRANSDUCER - REMOV-
AL).(4) Disconnect the discharge line from the con-
denser inlet. Install plugs in, or tape over all of the
opened refrigerant line fittings.
(5) Remove the bolt that secures the discharge line
fitting to compressor. Install plugs in, or tape over all
of the opened refrigerant line fittings.
(6) Remove the discharge line assembly from the
vehicle.
INSTALLATION
INSTALLATION - 2.7L TURBO DIESEL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.
High pressures are produced in the refrigerant sys-
tem when the air conditioning compressor is operat-
ing. Extreme care must be exercised to make sure
that each of the refrigerant system connections is
pressure-tight and leak free. It is a good practice to
inspect all flexible hose refrigerant lines at least once
a year to make sure they are in good condition and
properly routed.
(1) Carefully position the discharge line in the
vehicle.
(2) Remove the cap and install the discharge line
on the compressor. Be certain the sealing o-ring is
well lubricated with PAG oil and free of tears. Torque
the retaining fastener to 22 N´m (200 in. lbs.).
(3) Install the front splash shield (if equipped).
(4) Lower the vehicle from the hoist.
(5) Remove the cap and install the discharge line
on the condenser. Be certain the sealing o-ring is well
lubricated with PAG oil and free of tears. Torque the
retaining fastener to 28 N´m (21 ft. lbs.).
(6) Install the front fascia on the vehicle. Refer to
Front Fascia for the procedure.
(7) Install both headlamps in the vehicle. Refer to
Lamps/Lighting for the procedure.
(8) Install the a/c high pressure transducer, and
connect the electrical connector(Refer to 24 - HEAT-
Fig. 7 Suction-Discharge Lines- RHD (LHD-typical)
1 - SUCTION LINE
2 - H-BLOCK
3 - RECEIVER DRIER
4 - DISCHARGE LINE & SERVICE PORT
5 - A/C COMPRESSOR
6 - DISCHARGE LINE & CONDENSOR CONNECTION
24 - 64 PLUMBINGWJ
A/C DISCHARGE LINE (Continued)

INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.High pressures are produced in the refrigerant sys-
tem when the air conditioning compressor is operat-
ing. Extreme care must be exercised to make sure
that each of the refrigerant system connections is
pressure-tight and leak free. It is a good practice to
inspect all flexible hose refrigerant lines at least once
a year to make sure they are in good condition and
properly routed.
(1) Install the evaporator coil in the bottom half of
the HVAC housing. Be certain that the evaporator
foam insulator wrap is reinstalled.
(2) Reassemble the HVAC housing and install in
the vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION/HVAC HOUSING -
ASSEMBLY) (Refer to 24 - HEATING & AIR CON-
DITIONING/DISTRIBUTION/HVAC HOUSING -
INSTALLATION)
NOTE: If the evaporator is replaced, add 60 millili-
ters (2 fluid ounces) of refrigerant oil to the refrig-
erant system.
Fig. 11 HVAC HOUSING- CASE SEPARATED
1 - ELECTRICIAL CONNECTORS
2 - VACUUM ACTUATOR
3 - RECIRCULATION DOOR
4 - THERMAL EXPANSION VALVE
5 - BLOWER MOTOR RESISTOR/CONTROLLER
6 - BLOWER WHEEL
7 - EVAPORATOR AND TUBES
8 - FIN SENSOR PROBE9 - BLEND DOOR
10 - PIVOT SHAFT (MOTOR REMOVED)
11 - PANEL/OUTLET DOOR
12 - LOWER HOUSING
13 - VACUUM ACTUATORS
14 - UPPER HOUSING
15 - VACUUM HARNESS
24 - 70 PLUMBINGWJ
A/C EVAPORATOR (Continued)

pressure-tight and leak free. It is a good practice to
inspect all flexible hose refrigerant lines at least once
a year to make sure they are in good condition and
properly routed.
(1) When installing individual tubes, insert tube
into core ensuring that tube O-ring is seated in core
and not pinched. Hold tube in seated position while
installing the round tube-to-core clamp (Fig. 14).
NOTE: The round tube-to-heater-core clamp should
be left loose enough to turn the tube in the core.
Position the core in the housing, and then tighten
the tube-to-heater-core clamp after orienting the
tubes to the molded HVAC housing.
(2) Lower the heater core into the HVAC housing.
(3) Install the mode door actuator, if removed from
housing for core removal.
(4) Position the retainers over the heater core
tubes. Install and tighten the screws that secure the
heater core and retainers to the HVAC housing.
Tighten the screws to 2.2 N´m (20 in. lbs.).NOTE: The grounding strap is to be attached to the
lower heater core tube retainer.
(5) Reinstall the HVAC housing to the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - INSTALLA-
TION)
RECEIVER / DRIER
DESCRIPTION
The receiver/drier is mounted in the engine com-
partment between the condenser and is part of the
liquid line assembly. The filter/drier cannot be
repaired, if the filter/drier is faulty, damaged, left
open to the atmosphere or contaminated the line
assembly must be replaced.
OPERATION
The filter-drier performs a filtering action to pre-
vent foreign material in the refrigerant from contam-
inating the expansion valve. A desiccant bag is
mounted inside the filter-drier canister to absorb any
Fig. 13 HEATER CORE AND TUBES - (Typical)
1 - ELECTRICAL CONNECTORS
2 - EXPANSION VALVE
3 - ELECTRIC ACTUATOR
4 - OUTLET TO DEFROSTER DUCTS
5 - ELECTRIC ACTUATOR
6 - FLOOR DUCT
7 - TO REAR PASSENGER FLOOR AIR DUCTS8 - FLOOR DUCT
9 - HEATER CORE AND TUBES
10 - HOUSING DRAIN
11 - BLOWER MOTOR RESISTOR/CONTROLLER
12 - BLOWER MOTOR
13 - GROUND STRAP
24 - 72 PLUMBINGWJ
HEATER CORE (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

VISCOUS HEATER
DESCRIPTION
DESCRIPTION
The diesel engine has an engine mounted mechan-
ical device called a Viscous Heater that is used to
heat the coolant coming from the engine to the
heater core. The Viscous Heater is driven by the
engine fan belt and has a electro-mechanical clutch
which is controlled by the HVAC control unit.
DESCRIPTION - VISCOUS HEATER CLUTCH
The basic viscous heater clutch assembly consists
of a stationary electromagnetic coil, a hub bearing
and pulley assembly and a clutch plate. The electro-
magnetic coil unit and the hub bearing and pulley
assembly are each retained on the nose of the com-
pressor front housing with snap rings (Fig. 17). The
clutch plate is keyed to the viscous heater shaft and
secured with a nut. These components provide the
means to engage and disengage the viscous heater
from the engine accessory drive belt.
OPERATION
OPERATION - VISCOUS HEATER
The Viscous Heater is driven by the engine fan
belt. The Viscous Heater has an electro-mechanical
clutch that receives a signal from the HVAC control
head and the Viscous Heater controller that ener-
gizes and engages the clutch. Once engaged theclutch allows the Viscous Heater to increase the tem-
perature of the coolant flowing to the heater core,
which provides heat the passenger compartment
quicker than normal engines without the Viscous
Heater. The Viscous Heater generates heat by means
of friction which heats a special Silicon Oil within its
housing which is then transferred to the engine cool-
ant when the coolant passes over fins within the
pump. Please note that the coolant is isolated from
the silicon oil within the pump housing. When
demand for passenger compartment heat decreases
the Viscous Heater clutch will receive an input from
the Viscous heater controller to disengage.
OPERATION - VISCOUS HEATER CLUTCH
When the clutch coil is energized, it magnetically
draws the clutch into contact with the pulley and
drives the viscous heater shaft. When the coil is not
energized the pulley freewheels on the clutch hub
bearing, which is part of the pulley. The viscous
heater clutch and coil are the only serviced parts on
the viscous heater assembly. If the viscous heater is
inoperative or damaged the entire assembly must be
replaced. The viscous heater clutch engagement is
controlled by several components: the viscous heater
controller, the engine powertrain control module and
the HVAC control head.
REMOVAL
REMOVAL - VISCOUS HEATER
(1) Drain the engine coolant(Refer to 7 - COOL-
ING/ENGINE - STANDARD PROCEDURE).
(2) Remove the engine accessory drive belt(Refer to
7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Remove the heater hose clamps at the Viscous
Heater.
(4) Remove the heater hoses from the Viscous
Heater.
(5) Unplug the Viscous Heater clutch electrical
connector.
(6) Remove the bolts holding the Viscous Heater to
the mounting bracket.
(7) Remove the Viscous Heater from the vehicle.
REMOVAL - VISCOUS HEATER CLUTCH
(1) The viscous heater clutch can be serviced in
the vehicle and the cooling system does not have to
be drained.
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the serpentine drive belt(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
Fig. 17 CLUTCH ASSEMBLY- typical
1 - CLUTCH PLATE
2 - SHAFT KEY
3 - PULLEY
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
24 - 76 PLUMBINGWJ

(4) Unplug the clutch coil wire harness connector.
(5) Remove the bolts that secure the viscous
heater to the mounting bracket.
(6) Remove the viscous heater from the mounting
bracket. Support the viscous heater in the engine
compartment while servicing the clutch.
(7) Insert the two pins of the spanner wrench (spe-
cial Tool C-4489 or equivalent) into the holes of the
clutch plate. Hold the clutch plate stationary and
remove the hex nut (Fig. 18).
(8) Remove the clutch plate.
(9) Remove the clutch shims.
(10) Remove the external front housing snap ring
with snap ring pliers (Fig. 19).(11) Install the lip of the rotor puller (Special Tool
C-6141±1 or equivalent) into the snap ring groove
exposed in the previous step, and install the shaft
protector (Special Tool C-6141±2 or equivalent) (Fig.
20).
(12) Install the puller through bolts (Special Tool
C-6461 or equivalent) through the puller flange and
into the jaws of the rotor puller and tighten. Turn
the puller center bolt clockwise until the rotor is free
(Fig. 21).
(13) Remove the screw and retainer from the
clutch coil lead wire harness on the viscous heater
housing.
Fig. 18 CLUTCH NUT REMOVE-typical
1 - CLUTCH PLATE
2 - SPANNER
Fig. 19 EXTERNAL SNAP RING REMOVE- typical
1 - PULLEY
2 - SNAP RING PLIERS
Fig. 20 SHAFT PROTECTOR AND PULLER- typical
1 - PULLER JAW
2 - SHAFT PROTECTOR
Fig. 21 INSTALL PULLER PLATE- typical
1 - PULLER JAW
2 - PULLER
WJPLUMBING 24 - 77
VISCOUS HEATER (Continued)

(14) Remove the snap ring from the hub and
remove the clutch field coil (Fig. 22). Slide the clutch
field coil off of the hub.
INSTALLATION
INSTALLATION
(1) Install Viscous Heater to engine mounting
bracket.
(2) Install the Viscous Heater mounting bolts and
tighten to 33 N´m ( 25 ft. lbs.).
(3) Plug the wiring harness electrical connector to
the Viscous Heater clutch.
(4) Install heater hoses to the Viscous Heater con-
nections.
(5) Install heater hose clamps to Viscous Heater
connections.
(6) Install the engine accessory drive belt(Refer to
7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(7) Refill the engine cooling system(Refer to 7 -
COOLING/ENGINE - STANDARD PROCEDURE).
(8) Reconnect the battery negative cable.
(9) Operate vehicle and check for any coolant
leaks, repair as required.
INSTALLATION - VISCOUS HEATER CLUTCH
(1) Install the clutch field coil and snap ring.
(2) Install the screw and retainer on the clutch coil
lead wire harness on the viscous heater housing.
Tighten the screw to 2.2 N´m (20 in. lbs.)
(3) Align the rotor assembly squarely on the front
housing hub.
(4) Install the rotor bearing asembly with the
installer (Special Tool C-6871 or equalivent). Threadthe installer on the shaft, then turn the nut until the
rotor asembly is seated.
(5) Install the external front housing snap ring
with snap ring pliers. The bevel side of the snap ring
must be facing outward. Press the snap ring to make
sure it is properly seated in the groove.
CAUTION: If the snap ring is not fully seated in the
groove it will vibrate out, resulting in a clutch fail-
ure and severe damage to the front housing of the
compressor.
(6) Install the original clutch shims on the shaft.
(7) Install the clutch plate. Install the shaft hex
nut and tighten to 15±20 N´m (11±15 ft. lbs.).
(8) Check the clutch air gap with a feeler gauge
(Fig. 23). If the gap does not meet specification, add
or substract shims as required. The air gap specifica-
tion if 0.41 to 0.79 millimeters (0.016 to 0.031 inch-
es).
NOTE: The air gap is determined by the spacer
shims. When installing an original, or a new clutch
assembly, try the original shims first. When install-
ing a new clutch (and not having the old shims
available) use a 1.0, 0.50 and 0.13 millimeter (0.040,
0.020 and 0.005 inch) shim from the new clutch
hardware package that is provided with the new
clutch.
(9) Reinstall the viscous heater to the mounting
bracket. Tighten the mounting screws to 33 N´m (25
ft. lbs.).
(10) Reinstall the battery negative cable.
Fig. 22 CLUTCH FIELD COIL SNAP RING REMOVE-
typical
1 - COIL
2 - SNAP RING PLIERS
Fig. 23 CHECK CLUTCH AIR GAP-typical
1 - FEELER GAUGE
24 - 78 PLUMBINGWJ
VISCOUS HEATER (Continued)

EMISSIONS CONTROL
TABLE OF CONTENTS
page page
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - EMISSION CONTROL
SYSTEM.............................1
DESCRIPTION - STATE DISPLAY TEST
MODE...............................2
DESCRIPTION - CIRCUIT ACTUATION TEST
MODE...............................2
DESCRIPTION - DIAGNOSTIC TROUBLE
CODES..............................2DESCRIPTION - TASK MANAGER.........17
DESCRIPTION - MONITORED SYSTEMS . . . 17
DESCRIPTION - TRIP DEFINITION........19
DESCRIPTION - COMPONENT MONITORS . . 19
DESCRIPTION - NON-MONITORED
CIRCUITS...........................20
DESCRIPTION - HIGH AND LOW LIMITS . . . 20
DESCRIPTION - LOAD VALUE...........20
OPERATION - TASK MANAGER............21
EVAPORATIVE EMISSIONS................24
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - EMISSION CONTROL SYSTEM
The Powertrain Control Module (PCM) monitors
many different circuits in the fuel injection, ignition,
emission and engine systems. If the PCM senses a prob-
lem with a monitored circuit often enough to indicate an
actual problem, it stores a Diagnostic Trouble Code
(DTC) in the PCM's memory. If the code applies to a
non-emissions related component or system, and the
problem is repaired or ceases to exist, the PCM cancels
the code after 40 warm-up cycles. Diagnostic trouble
codes that affect vehicle emissions illuminate the Mal-
function Indicator (check engine) Lamp. Refer to Mal-
function Indicator Lamp in this section.
Certain criteria must be met before the PCM
stores a DTC in memory. The criteria may be a spe-
cific range of engine RPM, engine temperature,
and/or input voltage to the PCM.
The PCM might not store a DTC for a monitored cir-
cuit even though a malfunction has occurred. This may
happen because one of the DTC criteria for the circuit
has not been met.For example
,assume the diagnostic
trouble code criteria requires the PCM to monitor the
circuit only when the engine operates between 750 and
2000 RPM. Suppose the sensor's output circuit shorts to
ground when engine operates above 2400 RPM (result-
ing in 0 volt input to the PCM). Because the condition
happens at an engine speed above the maximum thresh-
old (2000 rpm), the PCM will not store a DTC.
There are several operating conditions for which
the PCM monitors and sets DTC's. Refer to Moni-
tored Systems, Components, and Non-Monitored Cir-
cuits in this section.Technicians must retrieve stored DTC's by connect-
ing the DRB scan tool (or an equivalent scan tool) to
the 16±way data link connector (Fig. 1).
NOTE: Various diagnostic procedures may actually
cause a diagnostic monitor to set a DTC. For
instance, pulling a spark plug wire to perform a
spark test may set the misfire code. When a repair
is completed and verified, connect the DRB scan
tool to the 16±way data link connector to erase all
DTC's and extinguish the MIL (check engine lamp).Fig. 1 Data Link (Diagnostic) Connector Location
1 - INSTRUMENT PANEL LOWER/LEFT EDGE
2 - DATA LINK CONNECTOR
WJEMISSIONS CONTROL 25 - 1