ECU CHRYSLER CARAVAN 2002 Service Manual

FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
INSTALLATION - COMPRESSOR MOUNTING
BRACKET - 2.4L ENGINE
(1) Position the compressor mounting bracket onto
the engine.
(2) Install and tighten the four screws that secure
the compressor mounting bracket to the engine.
Tighten the screws to 54 N´m (40 ft. lbs.).
(3) Reinstall the compressor onto the mounting
bracket. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/COMPRESSOR - INSTALLA-
TION).
CONDENSER
DESCRIPTION
The condenser is integral to a cooling module
which includes the radiator, the electric cooling fan,
the fan shroud, air seals and an automatic transmis-
sion oil cooler. The cooling module is located in the
air flow in the front of the engine compartment
behind the radiator grille. The condenser cannot be
repaired or adjusted and, if faulty or damaged, it
must be replaced. The condenser may be removed
from the cooling module for service without removing
the cooling module from the vehicle.
OPERATION
The condenser is a heat exchanger that allows the
high-pressure refrigerant gas being discharged by the
compressor to give up its heat to the air passing over
the condenser fins. When the refrigerant gas gives up
its heat, it condenses. When the refrigerant leaves
the condenser, it has become a high-pressure liquid
refrigerant. The volume of air flowing over the con-
denser fins is critical to the proper cooling perfor-
mance of the air conditioning system. Therefore, it is
important that there are no objects placed in front of
the radiator grille openings in the front of the vehicle
or foreign material on the condenser fins that might
obstruct air flow. Also, any factory-installed air seals
or shrouds must be properly reinstalled following
radiator or condenser service.
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).NOTE: Before removing the condenser, note the
location of each of the radiator and condenser air
seals. These air seals are used to direct air through
the condenser and radiator. The air seals must be
reinstalled in their proper locations in order for the
air conditioning and engine cooling systems to per-
form as designed.
(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/REFRIGERANT -
STANDARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Remove the two large screws that secure the
front fascia and the outboard ends of the radiator
sight shield to the radiator closure panel crossmem-
ber (Fig. 4).
(3) Remove the five small screws that secure the
front fascia grille inserts to the radiator sight shield.
(4) Remove the radiator sight shield from the radi-
ator closure panel crossmember.
(5) Remove the two screws that secure the hood
latch unit to the front of the radiator closure panel
crossmember and move the latch out of the way over
the top of the crossmember. Mark the location of
latch for reinstallation.
(6) Disconnect the hoses from the transmission oil
cooler fittings on the left side of the cooling module.
(Refer to 7 - COOLING/TRANSMISSION/TRANS
COOLER LINES - REMOVAL).
(7) Remove the nut that secures the discharge line
fitting to the condenser on the right side of the cool-
ing module.
Fig. 4 Radiator Sight Shield
1 - LARGE SCREWS (2)
2 - SMALL SCREWS (5)
3 - RADIATOR SIGHT SHIELD
4 - GRILLE INSERTS
5 - FRONT FASCIA
RSPLUMBING - FRONT24-65
COMPRESSOR (Continued)
ProCarManuals.com

(8) Disconnect the discharge line fitting from the
condenser inlet port.
(9) Remove the seal from the discharge line fitting
and discard.
(10) Install plugs in, or tape over the opened dis-
charge line fitting and the condenser inlet port.
(11) Remove the nut that secures the liquid line
fitting to the condenser on the right side of the cool-
ing module.
(12) Disconnect the liquid line fitting from the con-
denser outlet port.
(13) Remove the seal from the liquid line fitting
and discard.
(14) Install plugs in, or tape over the opened liquid
line fitting and the condenser outlet port.
(15) Remove the screw that secures the top of the
mounting bracket on each side of the condenser to
the cooling module (Fig. 5).
(16) Lift the condenser, transmission oil cooler, and
mounting brackets as a unit far enough to disengage
the locating pin that secures the mounting brackets
in the lower mount rubber isolators on each side of
the cooling module.
(17) Remove the condenser, transmission oil cooler,
and mounting brackets from the vehicle as a unit.(18) Remove the two screws that secure each
mounting bracket to the sides of the condenser.
(19) Remove the one screw that secures the left
mounting bracket to the side of the transmission oil
cooler.
(20) Remove the left mounting bracket from the
side of the condenser and transmission oil cooler.
(21) Remove the condenser from the right mount-
ing bracket and transmission oil cooler unit.
INSTALLATION
NOTE: If the condenser is being replaced, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the compressor in the vehi-
cle.
NOTE: Be certain that each of the radiator and con-
denser air seals are reinstalled in their proper loca-
tions. These air seals are required in order for the
air conditioning and engine cooling systems to per-
form as designed.
(1) Position the condenser to the right mounting
bracket and transmission oil cooler unit.
(2) Position the left mounting bracket onto the side
of the condenser and transmission oil cooler.
(3) Install and tighten the one screw that secures
the left mounting bracket to the side of the transmis-
sion oil cooler. Tighten the screw to 5 N´m (45 in.
lbs.).
(4) Install and tighten the two screws that secure
each mounting bracket to the sides of the condenser.
Tighten the screws to 5 N´m (45 in. lbs.).
(5) Position the condenser, transmission oil cooler,
and mounting brackets into the vehicle as a unit. Be
certain that the locating pins that secure the mount-
ing brackets are engaged in the lower mount rubber
isolators on each side of the cooling module.
NOTE: Verify that the condensor isolators are all
installed and positioned correctly.
(6) Install and tighten the two screws that secure
the top of the mounting bracket on each side of the
condenser to the cooling module. Tighten the screws
to 5 N´m (45 in. lbs.).
(7) Remove the tape or plugs from the condenser
outlet port and the liquid line fitting.
(8) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(9) Reconnect the liquid line fitting to the con-
denser outlet port on the right side of the cooling
module.
Fig. 5 Condenser Mounting
1 - SCREW (2)
2 - LOWER MOUNT ISOLATOR (2)
3 - CONDENSER
24 - 66 PLUMBING - FRONTRS
CONDENSER (Continued)
ProCarManuals.com

(10) Install and tighten the nut that secures the
liquid line fitting to the condenser. Tighten the nut to
23 N´m (17 ft. lbs.).
(11) Remove the tape or plugs from the condenser
inlet port and the discharge line fitting.
(12) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(13) Reconnect the discharge line fitting to the
condenser inlet port on the right side of the cooling
module.
(14) Install and tighten the nut that secures the
discharge line fitting to the condenser. Tighten the
nut to 23 N´m (17 ft. lbs.).
(15) Reconnect the hoses to the transmission oil
cooler fittings on the left side of the cooling module.
(Refer to 7 - COOLING/TRANSMISSION/TRANS
COOLER LINES - INSTALLATION).
(16) Reposition the hood latch unit to the front of
the radiator closure panel crossmember.
(17) Install and tighten the two screws that secure
the hood latch unit to the front of the radiator clo-
sure panel crossmember. Check and adjust the hood
latch as needed. Tighten the screws to 14 N´m (123
in. lbs.).
(18) Position the radiator sight shield onto the
radiator closure panel crossmember.
(19) Install and tighten the five small screws that
secure the front fascia grille inserts to the radiator
sight shield. Tighten the screws to 2 N´m (18 in. lbs.).
(20) Install and tighten the two large screws that
secure the front fascia and the outboard ends of the
radiator sight shield to the radiator closure panel
crossmember. Tighten the screws to 6 N´m (53 in.
lbs.).
(21) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(22) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
DISCHARGE LINE
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/REFRIGERANT -
STANDARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Remove the two large screws that secure the
front fascia and the outboard ends of the radiator
sight shield to the radiator closure panel crossmem-
ber (Fig. 6).
(3) Remove the five small screws that secure the
front fascia grille inserts to the radiator sight shield.
(4) Remove the radiator sight shield from the radi-
ator closure panel crossmember.
(5) Remove the nut that secures the discharge line
fitting to the condenser on the right side of the cool-
ing module (Fig. 7).
(6) Disconnect the discharge line fitting from the
condenser inlet port.
(7) Remove the seal from the discharge line fitting
and discard.
(8) Install plugs in, or tape over the opened dis-
charge line fitting and the condenser inlet port.
(9) Remove the nut that secures the discharge line
fitting to the top of the compressor (Fig. 8).
(10) Disconnect the discharge line fitting from the
compressor discharge port.
(11) Remove the seal from the discharge line fit-
ting and discard.
(12) Install plugs in, or tape over the opened dis-
charge line fitting and the compressor discharge port.
(13) Remove the discharge line from the engine
compartment.
Fig. 6 Radiator Sight Shield
1 - LARGE SCREWS (2)
2 - SMALL SCREWS (5)
3 - RADIATOR SIGHT SHIELD
4 - GRILLE INSERTS
5 - FRONT FASCIA
RSPLUMBING - FRONT24-67
CONDENSER (Continued)
ProCarManuals.com

INSTALLATION
(1) Position the discharge line into the engine com-
partment.
(2) Remove the tape or plugs from the compressor
discharge port and the discharge line fitting.
(3) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(4) Reconnect the discharge line fitting to the com-
pressor discharge port on the top of the compressor.(5) Install and tighten the nut that secures the
discharge line fitting to the compressor. Tighten the
nut to 23 N´m (17 ft. lbs.).
(6) Remove the tape or plugs from the condenser
inlet port and the discharge line fitting.
(7) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(8) Reconnect the discharge line fitting to the con-
denser inlet port on the right side of the cooling mod-
ule.
(9) Install and tighten the nut that secures the
discharge line fitting to the condenser. Tighten the
nut to 23 N´m (17 ft. lbs.).
(10) Position the radiator sight shield onto the
radiator closure panel crossmember.
(11) Install and tighten the five small screws that
secure the front fascia grille inserts to the radiator
sight shield. Tighten the screws to 2 N´m (18 in. lbs.).
(12) Install and tighten the two large screws that
secure the front fascia and the outboard ends of the
radiator sight shield to the radiator closure panel
crossmember. Tighten the screws to 6 N´m (53 in.
lbs.).
(13) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(14) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
EVAPORATOR
DESCRIPTION
The evaporator is located in the heater-A/C unit
housing, behind the instrument panel. The evapora-
tor is positioned in the heater-A/C housing so that all
air that enters the housing must pass over the fins of
the evaporator before it is distributed through the
system ducts and outlets. However, air passing over
the evaporator fins will only be conditioned when the
compressor is engaged and circulating refrigerant
through the evaporator tubes. The heater-A/C unit
housing must be removed from the vehicle to access
the evaporator for service. The evaporator cannot be
adjusted or repaired and, if faulty or damaged, it
must be replaced.
OPERATION
Refrigerant enters the evaporator from the expan-
sion valve as a low-temperature, low-pressure liquid/
vapor mixture. As air flows over the fins of the evap-
orator, the humidity in the air condenses on the fins,
Fig. 7 Condenser Connections
1 - CONDENSER
2 - DISCHARGE LINE FITTING
3 - LIQUID LINE FITTING
4 - NUT
Fig. 8 Discharge Line
1 - DISCHARGE LINE
2 - NUT
3 - DISCHARGE LINE FITTING
4 - STUD
5 - DISCHARGE PORT
24 - 68 PLUMBING - FRONTRS
DISCHARGE LINE (Continued)
ProCarManuals.com

and the heat from the air is absorbed by the refrig-
erant. Heat absorption causes the refrigerant to boil
and vaporize. The refrigerant becomes a low-pressure
gas when it leaves the evaporator.
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING),
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING),
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - HEATER PLUMB-
ING).
(1) Remove the HVAC unit housing from the vehi-
cle. (Refer to 24 - HEATING & AIR CONDITION-
ING/DISTRIBUTION - FRONT/HVAC HOUSING -
REMOVAL).
(2) Remove the heater core tubes from the heater
core. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/HEATER CORE -
REMOVAL - HEATER CORE TUBES).
(3) Remove and discard the foam seal from the
HVAC housing seal flange around the fresh air inlet
opening and the expansion valve/evaporator tube
opening on the dash panel side of the unit.
(4) Remove the expansion valve from the evapora-
tor inlet and outlet tube fittings. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/EXPANSION VALVE - REMOVAL).
(5) Disconnect the HVAC wire harness connector
for the blower motor from the motor connector recep-
tacle on the bottom of the outboard end of the evap-
orator housing.
(6) Disengage the HVAC wire harness from the
routing clips molded into the outside of the HVAC
housing components.
(7) Remove the three screws from the dash panel
side of the unit that secure the top of the distribution
housing to the inboard end of the evaporator housing
(Fig. 9).
(8) Pull the top of the distribution housing away
from the evaporator housing far enough to disengage
the two hook formations on the bottom of the distri-
bution housing from the two receptacles on the evap-
orator housing (Fig. 10).
(9) Remove the two screws that secure the upper
intake air housing to the lower intake air housing.
(10) Remove the three screws that secure the
upper intake air housing to the top of the outboard
end of the evaporator housing. Be certain not to miss
the screw located just inside the inboard side of the
fresh air intake opening.(11) Remove the upper intake air housing from the
top of the evaporator housing to expose the recircu-
lation air door and the blower wheel housing (Fig.
11).
(12) Remove the two screws that secure the upper
half of the recirculation air door to the lower half of
the door.
(13) Remove the upper half of the recirculation air
door from the lower half of the door (Fig. 12).
(14) Remove the twelve screws around the perime-
ter of the evaporator housing that secure the upper
housing half to the lower half.
Fig. 9 HVAC Housing
1 - DISTRIBUTION HOUSING
2 - SCREWS (3)
3 - HVAC WIRING HARNESS
4 - ROUTING CLIP
5 - EVAPORATOR HOUSING
Fig. 10 Distribution Housing Hooks
1 - RECEPTACLES ON EVAPORATOR HOUSING
2 - HOOKS ON DISTRIBUTION HOUSING
RSPLUMBING - FRONT24-69
EVAPORATOR (Continued)
ProCarManuals.com

(15) Carefully separate and remove the upper half
of the evaporator housing from the lower half. Be cer-
tain not to lose the rubber grommet for the HVAC
wire harness evaporator temperature sensor take
out. This grommet is located on the inboard side of
the flange around the expansion valve/evaporator
tube opening on the dash panel side of the unit,
where it is captured in a notched area between the
upper and lower housing halves (Fig. 13).(16) Carefully lift the evaporator and its foam
wrap out of the lower half of the evaporator housing
as a unit. Be certain not to lose the clam shell type
rubber seal that is fitted to the evaporator inlet and
outlet tubes where they exit the evaporator housing.
INSTALLATION
NOTE: If the evaporator is being replaced, add 60
milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the compressor in the vehi-
cle.
(1) Carefully lower the evaporator and its foam
wrap into the lower half of the evaporator housing as
a unit. Be certain that the clam shell type rubber
seal is fitted to the evaporator inlet and outlet tubes
where they exit the evaporator housing.
(2) Position the upper half of the evaporator hous-
ing onto the lower half. Be certain that the rubber
grommet and the HVAC wire harness take out for
the evaporator temperature sensor are captured in
the notched area between the upper and lower hous-
ing halves.
(3) Install and tighten the twelve screws around
the perimeter of the evaporator housing that secure
the upper housing half to the lower half. Tighten the
screws to 2 N´m (18 in. lbs.).
(4) Position the upper half of the recirculation air
door onto the lower half of the door.
(5) Install and tighten the two screws that secure
the upper half of the recirculation air door to the
Fig. 11 Upper Intake Air Housing
1 - EVAPORATOR HOUSING
2- UPPER INTAKE AIR HOUSING
3 - RECIRCULATION AIR DOOR
4 - BLOWER WHEEL
Fig. 12 Recirculation Air Door
1 - EVAPORATOR HOUSING
2 - UPPER RECIRCULATION AIR DOOR
3 - LOWER INTAKE AIR HOUSING
Fig. 13 Evaporator Housing
1 - LOWER EVAPORATOR HOUSING
2 - UPPER EVAPORATOR HOUSING
3 - BLOWER WHEEL
4 - EVAPORATOR
24 - 70 PLUMBING - FRONTRS
EVAPORATOR (Continued)
ProCarManuals.com

lower half of the door. Tighten the screws to 2 N´m
(18 in. lbs.).
(6) Position the upper intake air housing onto the
top of the evaporator housing over the recirculation
air door and the blower wheel housing. Be certain
that the upper pivot of the recirculation air door is
captured in the pivot receptacle of the upper intake
air housing.
(7) Install and tighten the three screws that secure
the upper intake air housing to the top of the out-
board end of the evaporator housing. Be certain not
to miss the screw located just inside the inboard side
of the fresh air intake opening. Tighten the screws to
2 N´m (18 in. lbs.).
(8) Install and tighten the two screws that secure
the upper intake air housing to the lower intake air
housing. Tighten the screws to 2 N´m (18 in. lbs.).
(9) Engage the two hook formations on the bottom
of the distribution housing in the two receptacles on
the evaporator housing.
(10) Roll the top of the distribution housing up
into position against the evaporator housing.
(11) Install and tighten the three screws from the
dash panel side of the unit that secure the top of the
distribution housing to the inboard end of the evapo-
rator housing. Tighten the screws to 2 N´m (18 in.
lbs.).
(12) Engage the HVAC wire harness in the routing
clips molded into the outside of the HVAC housing
components.
(13) Reconnect the HVAC wire harness connector
for the blower motor with the motor connector recep-
tacle on the bottom of the outboard end of the evap-
orator housing.
(14) Reinstall the expansion valve onto the evapo-
rator inlet and outlet tube fittings. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/EXPANSION VALVE - INSTALLATION).
(15) Install a new foam seal onto the HVAC hous-
ing seal flange around the fresh air inlet opening and
the expansion valve/evaporator tube opening on the
dash panel side of the unit.
(16) Reinstall the heater core tubes into the heater
core. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/HEATER CORE -
INSTALLATION - HEATER CORE TUBES).
(17) Reinstall the HVAC unit housing into the
vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - FRONT/HVAC HOUS-
ING - INSTALLATION).
(18) Run the HVAC Control Actuator Calibration
procedure(Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING)(Refer to 24
- HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING).EXPANSION VALVE
DESCRIPTION
The front ªHº valve-type thermal expansion valve
(TXV) is located at the dash panel between the liquid
and suction lines, and the evaporator coil. The
assembly consists of an H-valve body and a thermal
sensor. High-pressure, low temperature liquid refrig-
erant from the liquid line passes through the expan-
sion valve orifice, converting it into a low-pressure,
low-temperature mixture of liquid and gas before it
enters the evaporator coil. The expansion valve is a
factory calibrated unit and cannot be adjusted or
repaired. If faulty or damaged, the expansion valve
must be replaced.
OPERATION
A mechanical sensor in the expansion valve control
head monitors the temperature and pressure of the
refrigerant leaving the evaporator coil through the
suction line, and adjusts the orifice size at the liquid
line to let the proper amount of refrigerant into the
evaporator coil to meet the vehicle cooling require-
ments. Controlling the refrigerant flow through the
evaporator ensures that none of the refrigerant leav-
ing the evaporator is still in a liquid state, which
could damage the compressor. The thermo sensor
measures refrigerant suction gas temperature which
is monitored by the a/c control assembly.
DIAGNOSIS AND TESTING - EXPANSION VALVE
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).
NOTE: The expansion valve should only be tested
following testing of the compressor.
NOTE: Liquid CO is required to test the expansion
valve. This material is available from most welding
supply facilities. Liquid CO is also available from
companies which service and sell fire extinguish-
ers.
When testing the expansion valve, the work area
and the vehicle temperature must be 21É to 27É C
(70É to 85É F). To test the expansion valve:
(1) Connect a charging station or manifold gauge
set to the refrigerant system service ports. Verify the
refrigerant charge level.
RSPLUMBING - FRONT24-71
EVAPORATOR (Continued)
ProCarManuals.com

(2) Close all doors, windows and vents to the pas-
senger compartment.
(3) Set the heater-air conditioner controls so that
the compressor is operating, the temperature control
is in the highest temperature position, the mode door
is directing the output to the floor outlets, and the
blower is operating at the highest speed setting.
(4) Start the engine and allow it to idle at 1000
rpm. After the engine has reached normal operating
temperature, allow the passenger compartment to
heat up. This will create the need for maximum
refrigerant flow into the evaporator.
(5) If the refrigerant charge is sufficient, the dis-
charge (high pressure) gauge should read 965 to 1655
kPa (140 to 240 psi). The suction (low pressure)
gauge should read 140 kPa to 207 kPa (20 psi to 30
psi). If OK, go to Step 6. If not OK, replace the faulty
expansion valve.
WARNING:
PROTECT THE SKIN AND EYES FROM EXPOSURE
TO LIQUID CO. PERSONAL INJURY CAN RESULT.
(6) If the suction (low pressure) gauge reads
within the specified range, freeze the expansion valve
control head for 30 seconds using liquid CO or
another suitable super-cold material.Do not spray
R-134a or R-12 refrigerant on the expansion
valve control head for this test.The suction (low
pressure) gauge reading should drop by 10 psi. If OK,
go to Step 7 If not OK, replace the faulty expansion
valve.
(7) Allow the expansion valve control head to thaw.
The suction (low pressure) gauge reading should sta-
bilize at 140 kPa to 240 kPa (20 psi to 30 psi). If not
OK, replace the faulty expansion valve.
(8) When expansion valve testing is complete, test
the overall air conditioner performance. (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE TEST).
Remove all test equipment before returning the vehi-
cle to service.
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).
(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/REFRIGERANT -STANDARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the air cleaner housing from the right
side of the engine compartment.
(4) Disconnect the drain tube from the wiper mod-
ule drain on the right side of the engine compart-
ment.
(5) Disconnect the headlamp and dash wire har-
ness connector for the A/C pressure transducer from
the transducer on the front liquid line rear section
(Fig. 14).
(6) Remove the screw that secures the front liquid
line rear section fitting to the top of the filter-drier.
(7) Disconnect the liquid line fitting from the fil-
ter-drier outlet port.
(8) Remove the seal from the liquid line fitting and
discard.
(9) Install plugs in, or tape over the opened liquid
line fitting and the filter-drier outlet port.
(10) Remove the nut that secures the suction line
and liquid line fittings to the stud on the expansion
valve.
(11) Disconnect the suction line and liquid line fit-
tings from the expansion valve and move the lines
out of the way.
(12) Remove the seals from the suction line and
liquid line fittings and discard.
(13) Install plugs in, or tape over the opened suc-
tion line and liquid line fittings and both expansion
valve ports.
Fig. 14 Expansion Valve
1 - A/C PRESSURE TRANSDUCER
2 - EVAPORATOR TEMPERATURE SENSOR
3 - EXPANSION VALVE
4 - SUCTION LINE
5 - HIGH SIDE SERVICE PORT
6 - FRONT LIQUID LINE REAR SECTION
24 - 72 PLUMBING - FRONTRS
EXPANSION VALVE (Continued)
ProCarManuals.com

(14) Remove the two screws that secure the expan-
sion valve to the evaporator tube tapping plate.
(15) Disconnect the HVAC wire harness connector
for the evaporator temperature sensor from the sen-
sor on the top of the expansion valve.
(16) Remove the expansion valve from the evapo-
rator inlet and outlet tube fittings.
(17) Remove the seals from the evaporator inlet
and outlet tube fittings and discard.
(18) Install plugs in, or tape over the opened evap-
orator inlet and outlet tube fittings and both expan-
sion valve ports.
INSTALLATION
(1) Remove the tape or plugs from the evaporator
inlet and outlet tube fittings and both ports on the
back of the expansion valve.
(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the evaporator
inlet and outlet tube fittings.
(3) Position the expansion valve onto the evapora-
tor inlet and outlet tube fittings.
(4) Install and tighten the two screws that secure
the expansion valve to the evaporator tube tapping
plate plate. Tighten the screws to 11 N´m (97 in.
lbs.).
(5) Reconnect the HVAC wire harness connector
for the evaporator temperature sensor to the sensor
connector receptacle on the top of the expansion
valve.
(6) Remove the tape or plugs from the front liquid
line rear section and suction line fittings for the
expansion valve and both ports on the front of the
expansion valve.
(7) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the front liquid
line rear section and suction line fittings for the
expansion valve.
(8) Reconnect the liquid line and suction line fit-
tings to the expansion valve.
(9) Install and tighten the nut that secures the
suction line and liquid line fittings to the stud on the
expansion valve. Tighten the nut to 23 N´m (17 ft.
lbs.).
(10) Remove the tape or plugs from the liquid line
rear section fitting for the filter-drier and the filter-
drier outlet port.
(11) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(12) Reconnect the liquid line fitting to the filter-
drier outlet port on the top of the filter-drier.
(13) Install and tighten the screw that secures the
liquid line fitting to the filter-drier. Tighten the screw
to 2 N´m (18 in. lbs.).(14) Reconnect the headlamp and dash wire har-
ness connector for the A/C pressure transducer to the
transducer on the front liquid line rear section.
(15) Reconnect the drain tube to the wiper module
drain on the right side of the engine compartment.
(16) Reinstall the air cleaner housing into the
right side of the engine compartment.
(17) Reconnect the battery negative cable.
(18) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(19) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
HEATER CORE
DESCRIPTION
The heater core is located in the distribution hous-
ing of the heater-A/C unit, under the instrument
panel. It is a heat exchanger made of rows of tubes
and fins. One end of the core is fitted with a molded
plastic tank that includes integral heater core inlet
and outlet ports. The removable heater core tubes
are held in place these ports by a sealing plate
secured with a screw to the heater core tank. This
removable heater core tube arrangement allows the
heater core to be serviced without removing the heat-
er-A/C unit housing from the vehicle. The heater core
cannot be repaired and, if faulty or damaged, it must
be replaced.
OPERATION
Engine coolant is circulated through heater hoses
to the heater core at all times. As the coolant flows
through the heater core, heat removed from the
engine is transferred to the heater core fins and
tubes. Air directed through the heater core picks up
the heat from the heater core fins. The blend air door
allows control of the heater output air temperature
by controlling how much of the air flowing through
the heater-A/C unit housing is directed through the
heater core.
RSPLUMBING - FRONT24-73
EXPANSION VALVE (Continued)
ProCarManuals.com

REMOVAL
REMOVAL- HEATER CORE EXTENSION TUBES
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING FRONT - WARNING - HEATER PLUMB-
ING).
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 ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Drain the engine cooling system. (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(2) Disconnect and isolate the battery negative
cable.
(3) Disconnect the heater hoses from the heater
hose tubes. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/HEATER HOSE -
REMOVAL).
(4) Remove the silencer from beneath the driver
side end of the instrument panel. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL SILENCER - REMOVAL).
(5) Remove the three screws that secure the heater
core shield to the left end of the HVAC distribution
housing (Fig. 15).
(6) Pull the heater core shield rearward far enough
to disengage the two location tabs that position the
front of the shield to the receptacles in the two lower
finger formations of the evaporator housing near the
dash panel.
(7) Remove the heater core shield from the distri-
bution housing.
(8) Take the proper precautions to protect the car-
peting below the heater core from spilled engine cool-
ant and have absorbent toweling readily available to
clean up any spills.
(9) Remove the screw that secures the heater core
tube sealing plate to the heater core supply and
return ports (Fig. 16).(10) Push both heater core tubes simultaneously
toward the dash panel far enough to disengage their
fittings from the heater core supply and return ports.
(11) Install plugs in, or tape over the opened
heater core tube fittings and both heater core ports.
(12) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation.
(13) Pull both heater core tubes simultaneously
slightly away from the distribution housing and rear-
Fig. 15 Heater Core Shield
1 - HEATER/ AIR CONDITIONER HOUSING
2 - HEATER CORE SHIELD
3 - DISTRIBUTION HOUSING
4 - SCREWS (3)
5 - LOCATION TABS (2)
Fig. 16 Heater Core Tubes
1 - SEAL
2 - HEATER CORE TUBES
3 - SCREW
4 - HEATER CORE
5 - DISTRIBUTION HOUSING
6 - SEALING PLATE
24 - 74 PLUMBING - FRONTRS
HEATER CORE (Continued)
ProCarManuals.com