Evap CHRYSLER TOWN AND COUNTRY 2002 Workshop Manual
[x] Cancel search | Manufacturer: CHRYSLER, Model Year: 2002, Model line: TOWN AND COUNTRY, Model: CHRYSLER TOWN AND COUNTRY 2002Pages: 2399, PDF Size: 57.96 MB
Page 2250 of 2399
If coolant flow is verified and the heater floor out-
let temperature is insufficient, a mechanical problem
may exist.
POSSIBLE LOCATION OR CAUSE OF INSUFFICIENT HEAT
²Obstructed cowl air intake.
²Obstructed heater system outlets.
²Blend-air door not functioning properly.TEMPERATURE CONTROL
If heater floor outlet temperature cannot be
adjusted with the heater-A/C control temperature
control lever, one of the following could require ser-
vice:
²Blend-air door binding.
²Faulty blend-air door motor.
²Improper engine coolant temperature.
²Faulty heater-A/C control.
SPECIFICATIONS - HEATER-A/C SYSTEM
ITEM DESCRIPTION NOTES
Vehicle RS - Caravan, Town & Country, Voyager
System R134a with expansion valve(s)
Compressor Nippondenso - 10S20 ND-8 PAG Oil
Freeze±up Control evaporator temperature sensor expansion valve mounted - input
to heater-A/C control module
Low PSI Control liquid line mounted - input to
Powertrain Control Module (PCM)
- PCM opens compressor clutch
relay < 29.4 psi
High PSI Control pressure transducer liquid line mounted - input to
PCM - PCM opens compressor
clutch relay > 450 psi
pressure relief valve compressor mounted - opens >
495 psi
Control Head single zone, dual zone, and three zone
Manual Temperature Control (MTC) - or three
zone Automatic Temperature Control (ATC)PCI data bus messaging - ATC
uses three infrared temperature
sensors - two front/one rear
Mode Door electric actuator Control head driven
Blend Air Door electric actuator
Fresh/Recirc Door electric actuator
Blower Motor control head switch resistor and relay with MTC,
power module and relay with ATC
Cooling Fans pulse width modulated variable speed PCM control through solid state
fan relay
Clutch
Clutch Control PCM PCM control through compressor
clutch relay
Clutch Coil Draw 2.2 amps @ 12V 0.5amps@ 70É F
Compressor Clutch Air Gap 0.0209- 0.0359
Diagnostics DRBIIITscan tool
RSHEATING & AIR CONDITIONING24-7
HEATING & AIR CONDITIONING (Continued)
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CONTROLS - FRONT
TABLE OF CONTENTS
page page
A/C HEATER CONTROL
STANDARD PROCEDURE - HEATER-A/C
CONTROL CALIBRATION................8
REMOVAL.............................9
INSTALLATION..........................9
A/C PRESSURE TRANSDUCER
DESCRIPTION - A/C PRESSURE
TRANSDUCER.......................10
OPERATION...........................10
DIAGNOSIS AND TESTING - A/C PRESSURE
TRANSDUCER.......................10
REMOVAL.............................11
INSTALLATION.........................11
BLEND DOOR ACTUATOR
DESCRIPTION.........................11
OPERATION...........................11
REMOVAL.............................12
INSTALLATION.........................12
BLOWER MOTOR RELAY
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING - BLOWER
MOTOR RELAY.......................14
REMOVAL.............................14
INSTALLATION.........................14
BLOWER MOTOR RESISTOR
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING - BLOWER
MOTOR RESISTOR....................15
REMOVAL.............................16
INSTALLATION.........................16
COMPRESSOR CLUTCH
DESCRIPTION.........................16
OPERATION...........................17
STANDARD PROCEDURE
STANDARD PROCEDURE - COMPRESSOR
CLUTCH AIR GAP.....................17STANDARD PROCEDURE - COMPRESSOR
CLUTCH BREAK-IN....................17
REMOVAL.............................17
INSPECTION - COMPRESSOR CLUTCH/COIL . 18
INSTALLATION.........................19
COMPRESSOR CLUTCH COIL
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH COIL........................20
COMPRESSOR CLUTCH RELAY
DESCRIPTION.........................21
OPERATION...........................21
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH RELAY......................22
REMOVAL.............................22
INSTALLATION.........................22
EVAPORATOR TEMPERATURE SENSOR
DESCRIPTION.........................22
OPERATION...........................23
REMOVAL.............................23
INSTALLATION.........................23
INFRARED TEMPERATURE SENSOR
DESCRIPTION.........................24
OPERATION...........................24
MODE DOOR ACTUATOR
DESCRIPTION.........................24
OPERATION...........................25
REMOVAL.............................25
INSTALLATION.........................25
POWER MODULE
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................26
INSTALLATION.........................27
RECIRCULATION DOOR ACTUATOR
DESCRIPTION.........................27
OPERATION...........................27
REMOVAL.............................28
INSTALLATION.........................28
A/C HEATER CONTROL
STANDARD PROCEDURE - HEATER-A/C
CONTROL CALIBRATION
The heater-A/C control module must be recali-
brated each time an actuator motor or the control
module is replaced. If the vehicle is so equipped, the
calibration procedure also includes rear HVAC posi-
tions for each actuator motor.(1) Turn the ignition switch to the On position.
(2) Simultaneously depress and hold the Power
and Recirculation buttons on the heater-A/C control
for at least five seconds. The manual heater-A/C con-
trol power Light Emitting Diode (LED) and Recircu-
lation LED, or the Automatic Temperature Control
(ATC) heater-A/C control Delay and Recirculation
graphics will begin to flash when the calibration pro-
cedure has begun.
24 - 8 CONTROLS - FRONTRS
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REMOVAL
The single zone heating and air conditioning sys-
tem is equipped with a single blend door actuator.
The dual zone system has two blend door actuators,
one for the driver side blend air door and one for the
passenger side blend air door. The same service pro-
cedures can be used for each of these actuators.
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) Disconnect and isolate the battery negative
cable.
(2) Remove the silencer from beneath the driver
side end of the instrument panel. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL SILENCER - REMOVAL).
(3) Remove the three screws that secure the heater
core shield to the left end of the HVAC distribution
housing (Fig. 4).(4) 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 heater/ air conditioner hous-
ing near the dash panel.
(5) Remove the heater core shield from the distri-
bution housing.
(6) Disconnect the HVAC wire harness connector
for the blend door actuator from the actuator connec-
tor receptacle (Fig. 5).
(7) Remove the two screws that secure the blend
door actuator to the distribution housing.
(8) Remove the blend door actuator from the dis-
tribution housing.
INSTALLATION
(1) Position the blend door actuator onto the heat-
er/air conditioner housing. If necessary, rotate the
actuator slightly to align the splines on the actuator
output shaft with those in the blend air door linkage.
(2) Install and tighten the two screws that secure
the blend door actuator to the distribution housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the HVAC wire harness connector
for the blend door actuator to the actuator connector
receptacle.
(4) Position the heater core shield onto the distri-
bution housing. Be certain that the two location tabs
on the front of the shield are engaged in the recepta-
cles in the two lower finger formations of the evapo-
rator housing near the dash panel.
Fig. 4 Heater Core Shield
1 - HEATER/ AIR CONDITIONER HOUSING
2 - HEATER CORE SHIELD
3 - DISTRIBUTION HOUSING
4 - SCREWS (3)
5 - LOCATION TABS (2)
Fig. 5 Blend Door Actuator
1 - CONNECTOR
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - DRIVER BLEND DOOR ACTUATOR (DUAL-ZONE ONLY)
5 - HEATER CORE
6 - BLEND DOOR ACTUATOR (SINGLE ZONE) OR PASSENGER
BLEND DOOR ACTUATOR (DUAL-ZONE)
24 - 12 CONTROLS - FRONTRS
BLEND DOOR ACTUATOR (Continued)
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BLOWER MOTOR RESISTOR
DESCRIPTION
A blower motor resistor is used on this model when
it is equipped with the manual heater-A/C control
(Fig. 9). Models equipped with the optional Auto-
matic Temperature Control (ATC) use a blower power
module, instead of the blower motor resistor. The
blower motor resistor is installed in a mounting hole
in the heater/AC housing, directly behind the glove
box opening of the instrument panel. The resistor
consists of a molded plastic mounting plate with two
integral connector receptacles. Concealed behind the
mounting plate within the heater/AC housing are
four coiled resistor wires contained within a protec-
tive stamped steel cage. The resistor mounting plate
is secured with two screws to the heater/AC housing
and is accessed for service by rolling down the glove
box from the instrument panel.
The blower motor resistor wires will get hot when
in use. Do not touch the resistor wires or the protec-
tive cage if the blower motor has been running. The
blower motor resistor cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The blower motor resistor is connected to the vehi-
cle electrical system through a dedicated take out
and connector of the instrument panel wire harness.
A second connector receptacle receives the pigtail
wire connector from the blower motor. The blower
motor resistor has multiple resistor wires, each ofwhich will reduce the current flow through the
blower motor to change the blower motor speed. The
blower motor switch in the manual heater-A/C con-
trol directs the ground path for the blower motor
through the correct resistor wire to obtain the
selected speed. With the blower motor switch in the
lowest speed position, the ground path for the motor
is applied through all of the resistor wires. Each
higher speed selected with the blower motor switch
applies the blower motor ground path through fewer
of the resistor wires, increasing the blower motor
speed. When the blower motor switch is in the high-
est speed position, the blower motor resistor wires
are bypassed and the blower motor receives a direct
path to ground through the blower motor switch. The
blower motor resistor may be diagnosed using con-
ventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RESISTOR
Refer to the appropriate wiring information. The
wiring 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 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) Disconnect and isolate the battery negative
cable.
(2) Disconnect the instrument panel wire harness
connector for the blower motor resistor and the
blower motor pigtail wire connector from the resistor
connector receptacles.
(3) Check for continuity between each of the
blower motor switch input terminals of the blower
motor resistor and the resistor output terminal. In
each case there should be continuity. If OK, repair
the instrument panel wire harness circuits between
the blower motor switch and the blower motor resis-
tor or the blower motor pigtail wires as required. If
not OK, replace the faulty blower motor resistor.
Fig. 9 Blower Motor Resistor
1 - BLOWER MOTOR RESISTOR
2 - INSTRUMENT PANEL WIRE HARNESS
3 - SCREW (2)
4 - GLOVE BOX OPENING LOWER REINFORCEMENT
5 - BLOWER MOTOR PIGTAIL WIRE
6 - EVAPORATOR HOUSING
RSCONTROLS - FRONT24-15
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REMOVAL
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.
WARNING: THE BLOWER MOTOR RESISTOR MAY
GET VERY HOT DURING NORMAL OPERATION. IF
THE BLOWER MOTOR WAS TURNED ON, WAIT
FIVE MINUTES TO ALLOW THE BLOWER MOTOR
RESISTOR TO COOL BEFORE PERFORMING DIAG-
NOSIS OR SERVICE. FAILURE TO TAKE THIS PRE-
CAUTION CAN RESULT IN PERSONAL INJURY.
CAUTION: Do not operate the blower motor with the
blower motor resistor removed from the circuit.
Failure to take this precaution can result in vehicle
damage.
(1) Disconnect and isolate the battery negative
cable.
(2) Open the glove box.
(3) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box downward.
(4) Reach through the glove box opening to access
and disconnect the instrument panel wire harness
connector for the blower motor resistor from the
resistor connector receptacle (Fig. 10).
(5) Reach through the glove box opening to access
and disconnect the blower motor pigtail wire connec-
tor from the resistor connector receptacle.
(6) Remove the two screws that secure the blower
motor resistor to the evaporator housing.
(7) Remove the blower motor resistor from the
evaporator housing.
INSTALLATION
CAUTION: Do not operate the blower motor with the
blower motor resistor removed from the circuit.
Failure to take this precaution can result in vehicle
damage.(1) Position the blower motor resistor into the
evaporator housing.
(2) Install and tighten the two screws that secure
the blower motor resistor to the evaporator housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the blower motor pigtail wire con-
nector to the blower motor resistor connector recep-
tacle.
(4) Reconnect the instrument panel wire harness
connector for the blower motor resistor to the resistor
connector receptacle.
(5) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box upward.
(6) Close and latch the glove box.
(7) Reconnect the battery negative cable.
COMPRESSOR CLUTCH
DESCRIPTION
The compressor clutch assembly consists of a sta-
tionary electromagnetic coil with a zener diode, a hub
bearing and pulley assembly, and a clutch plate (Fig.
11). The electromagnetic coil unit and the hub bear-
ing and pulley assembly are each retained on the
nose of the compressor front housing with snap rings.
The clutch plate is keyed or splined to the compres-
sor shaft, and secured with a bolt.
Fig. 10 Blower Motor Resistor
1 - BLOWER MOTOR RESISTOR
2 - INSTRUMENT PANEL WIRE HARNESS
3 - SCREW (2)
4 - GLOVE BOX OPENING LOWER REINFORCEMENT
5 - BLOWER MOTOR PIGTAIL WIRE
6 - EVAPORATOR HOUSING
24 - 16 CONTROLS - FRONTRS
BLOWER MOTOR RESISTOR (Continued)
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The compressor clutch plate and pulley unit, or the
clutch coil are available for separate service replace-
ment. The clutch coil zener diode is integral to the
clutch coil pigtail wire and connector and, if faulty or
damaged, the clutch electromagnetic coil unit must
be replaced.
OPERATION
The compressor clutch components provide the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
clutch plate into contact with the clutch pulley and
drives the compressor shaft. When the coil is not
energized, the pulley freewheels on the clutch hub
bearing, which is part of the pulley.
A zener diode is connected in parallel with the
clutch electromagnetic coil. This diode controls the
dissipation of voltage induced into the coil windings
by the collapsing of the electromagnetic fields that
occurs when the compressor clutch is disengaged.
The zener diode dissipates this induced voltage by
regulating a current path to ground. This arrange-
ment serves to protect other circuits and components
from potentially damaging voltage spikes in the vehi-
cle electrical system that might occur if the voltage
induced in the clutch coil windings could not be dis-
sipated.
The compressor clutch engagement is controlled by
several components: the heater-A/C controls in the
passenger compartment, the A/C pressure transducer
on the liquid line, the evaporator temperature sensor
on the expansion valve, the Powertrain Control Mod-ule (PCM) in the engine compartment, and the com-
pressor clutch relay in the Intelligent Power Module
(IPM). The PCM may delay compressor clutch
engagement for up to thirty seconds. (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION - PCM OPERATION).
STANDARD PROCEDURE
STANDARD PROCEDURE - COMPRESSOR
CLUTCH AIR GAP
If a new clutch plate and/or clutch pulley are being
used, the air gap between the clutch plate and clutch
pulley must be checked using the following proce-
dure:
(1) Using feeler gauges, measure the air gap
between the clutch plate and the clutch pulley fric-
tion surfaces.
(2) If the air gap is not between 0.5 and 0.9 mm
(0.020 and 0.035 in.), add or subtract shims until the
desired air gap is obtained.
NOTE: The shims may compress after tightening
the compressor shaft bolt. Check the air gap in four
or more places on the clutch plate to verify that the
air gap is still correct. Spin the clutch pulley before
making the final air gap check.
STANDARD PROCEDURE - COMPRESSOR
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
check that the compressor clutch coil is performing to
specifications. (Refer to 24 - HEATING & AIR CON-
DITIONING/CONTROLS - FRONT/COMPRESSOR
CLUTCH COIL - DIAGNOSIS AND TESTING). If
the clutch coil is performing to specifications, per-
form the compressor clutch break-in procedure. This
procedure (burnishing) will seat the opposing friction
surfaces and provide a higher compressor clutch
torque capability.
(1) Set the heater-A/C controls to the A/C mode,
with the blower switch in the highest speed position.
(2) Start the engine and hold the engine speed at
1500 to 2000 rpm.
(3) Cycle the compressor clutch On and Off about
twenty times (five seconds On, then five seconds Off).
REMOVAL
The refrigerant system can remain fully charged
during compressor clutch, pulley, or coil replacement.
Although the compressor assembly must be removed
from its mounting, the compressor clutch can be ser-
vice with the compressor in the vehicle.
Fig. 11 Compressor Clutch - Typical
1 - CLUTCH PLATE
2 - SHAFT KEY (SOME MODELS)
3 - PULLEY AND BEARING
4 - CLUTCH COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
RSCONTROLS - FRONT24-17
COMPRESSOR CLUTCH (Continued)
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Page 2265 of 2399
a battery current output only when the compressor
clutch relay coil is de-energized.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices, and grounds.
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH RELAY
The compressor clutch relay (Fig. 17) is located in
the Intelligent Power Module (IPM), which is in the
engine compartment near the battery. See the fuse
and relay layout map molded into the inner surface
of the IPM cover for compressor clutch relay identifi-
cation and location. Remove the relay from the IPM
to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75 5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, use a DRBIIItscan tool to perform
further diagnosis of the relay circuits. Refer to the
appropriate diagnostic information. If not OK,
replace the faulty relay.
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unlatch and remove the cover from the Intelli-
gent Power Module (IPM).
(3) See the fuse and relay layout map molded into
the inner surface of the IPM cover for compressor
clutch relay identification and location.
(4) Remove the compressor clutch relay from the
IPM by pulling it straight up.
INSTALLATION
(1) See the fuse and relay layout map molded into
the inner surface of the Intelligent Power Module
(IPM) cover for compressor clutch relay identification
and location.
(2) Position the compressor clutch relay to the
proper receptacle in the IPM.
(3) Align the compressor clutch relay terminals
with the terminal cavities in the IPM relay recepta-
cle.
(4) Push down firmly on the compressor clutch
relay until the terminals are fully seated in the ter-
minal cavities in the IPM receptacle.
(5) Install and latch the cover onto the IPM.
(6) Reconnect the battery negative cable.
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator temperature sensor is a switch that
is installed on the top of the expansion valve in the
right rear corner of the engine compartment (Fig.
18). The sensor has a small probe that is inserted in
a small well in the body of the expansion valve that
is filled with a special silicone-based thermal grease.
A small molded plastic push-in retainer secures the
sensor to a threaded hole in the top surface of the
expansion valve. Two terminals within a molded
plastic connector receptacle on the sensor connect it
to the vehicle electrical system through a take out
and connector of the HVAC wire harness.
Fig. 17 Compressor Clutch Relay
24 - 22 CONTROLS - FRONTRS
COMPRESSOR CLUTCH RELAY (Continued)
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Page 2266 of 2399
The evaporator temperature sensor cannot be
adjusted or repaired and, if faulty or damaged, it
must be replaced.
OPERATION
The evaporator temperature sensor monitors the
temperature of the evaporator through its connection
to the top of the expansion valve. The sensor will
change its internal resistance in response to the tem-
peratures it monitors. The heater-A/C control module
is connected to the sensor through a sensor ground
circuit and a sensor signal circuit. As the evaporator
temperature increases, the resistance of the sensor
decreases and the voltage monitored by the module
decreases. The module uses this monitored voltage
reading to an indication of the evaporator tempera-
ture. The heater-A/C control module is programmed
to respond to this input by sending electronic mes-
sages to the Powertrain Control Module (PCM) over
the Programmable Communications Interface (PCI)
data bus, and the PCM then cycles the air condition-
ing compressor clutch as necessary to optimize air
conditioning system performance and to protect the
system from evaporator freezing. The external loca-
tion of the sensor and the use of a screw allows the
sensor to be removed or installed from the expansion
valve without disturbing the refrigerant in the sys-
tem. The evaporator temperature sensor is diagnosed
using a DRBIIItscan tool. Refer to the appropriate
diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the air cleaner housing from the right
side of the engine compartment.
(3) Remove the windshield wiper assembly from
the vehicle(Refer to 8 - ELECTRICAL/WIPERS/
WASHERS/WIPER MODULE - REMOVAL).
(4) Remove the temperature sensor attaching
screw from the expansion valve.
(5) Pull the evaporator temperature sensor away
from the expansion valve far enough to access the
red release ring on the wiring connector. Push the
red ring toward the connector to release lock and
remove the HVAC wire harness connector from the
temperature sensor.
(6) Remove the evaporator temperature sensor
from the engine compartment. Please note that any
grease removed with the old temperature sensor
must be replaced, failure to do so could result in poor
a/c performance.
INSTALLATION
(1) Position the evaporator temperature sensor
into the right rear corner of the engine compartment.
Please make sure any grease removed with the old
sensor has been replaced before the new sensor is
installed, failure to do so could lead to poor a/c per-
formance.
(2) Reconnect the HVAC wire harness connector
for the evaporator temperature sensor to the sensor
connector receptacle.
(3) Position the evaporator temperature sensor
onto the top of the expansion valve with the sensor
probe inserted into the well in the expansion valve.
(4) Install the temperature sensor retaining screw
and tighten.
(5) Install the window wiper assembly to the vehi-
cle(Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER MODULE - INSTALLATION).
(6) Reinstall the air cleaner housing into the right
side of the engine compartment.
(7) Reconnect the battery negative cable.
(8) Run the HVAC Cool Down test to verify system
is operating properly(Refer to 24 - HEATING & AIR
CONDITIONING - DIAGNOSIS AND TESTING).
Fig. 18 Evaporator Temperature Sensor
1 - RIGHT FRONT STRUT TOWER
2 - EVAPORATOR TEMPERATURE SENSOR
3 - EXPANSION VALVE
4 - DASH PANEL
5 - RETAINER
RSCONTROLS - FRONT24-23
EVAPORATOR TEMPERATURE SENSOR (Continued)
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Page 2267 of 2399
INFRARED TEMPERATURE
SENSOR
DESCRIPTION
The infrared temperature sensor consists of two
infrared transducers that are concealed behind a
clear lens located near the bottom of the center panel
outlet near the top of the instrument panel center
bezel (Fig. 19). These sensors are used only on mod-
els equipped with the optional Automatic Tempera-
ture Control (ATC) heating and air conditioning
system. A molded plastic connector receptacle on the
bottom of the panel outlet unit is concealed behind
the center bezel. A short, dedicated jumper wire har-
ness routed behind the center bezel connects the sen-
sors directly to the ATC heater-A/C control module
near the bottom of the center bezel. The infrared
temperature sensor is integral to the center bezel
panel outlet unit. The infrared sensors cannot be
adjusted or repaired and, if faulty or damaged, the
center bezel panel outlet unit must be replaced.
OPERATION
The dual infrared temperature sensors provide
independent measurement inputs to the Automatic
Temperature Control (ATC) heater-A/C control mod-
ule that indicates the surface temperature of the
driver seat and front seat passenger seat occupants.
By using a surface temperature measurement, rather
than an air temperature measurement, the ATC sys-
tem is able to adjust itself to the comfort level as per-
ceived by the occupant. This allows the system to
detect and compensate for other ambient conditions
affecting comfort levels, such as solar heat gain orevaporative heat loss. The ATC system logic responds
to the infrared sensor inputs by calculating and
adjusting the air flow temperature and air flow rate
needed to properly obtain and maintain the individ-
ually selected comfort level temperatures of both the
driver and passenger seat occupants. The ATC heat-
er-A/C control module continually monitors the infra-
red sensor circuits, and will store a Diagnostic
Trouble Code (DTC) for any problem it detects. This
DTC information can be retrieved and the infrared
temperature sensor diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
MODE DOOR ACTUATOR
DESCRIPTION
The mode door actuator is a reversible, 12-volt
Direct Current (DC), servo motor (Fig. 20). The sin-
gle mode door actuator is located on the driver side
end of the heater-A/C housing unit, close to the top of
the distribution housing. The mode door actuator is
mechanically connected to the mode door. The mode
door actuator is interchangeable with the actuators
for the blend air door(s) and the recirculation air
door. Each actuator is contained within an identical
black molded plastic housing with an integral wire
connector receptacle. Two integral mounting tabs
allow the actuator to be secured with two screws to
the heater-A/C unit housing. Each actuator also has
an identical output shaft with splines that connects
Fig. 19 Infrared Temperature Sensor
1 - INSTRUMENT PANEL CENTER BEZEL
2 - CENTER BEZEL OUTLETS
3 - INFRARED TEMPERATURE SENSOR
Fig. 20 Mode Door Actuator
1 - CONNECTOR
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - DRIVER BLEND DOOR ACTUATOR (DUAL-ZONE ONLY)
5 - HEATER CORE
6 - BLEND DOOR ACTUATOR (SINGLE ZONE) OR PASSENGER
BLEND DOOR ACTUATOR (DUAL-ZONE)
24 - 24 CONTROLS - FRONTRS
ProCarManuals.com
Page 2269 of 2399
(2) Install and tighten the two screws that secure
the mode door actuator to the distribution housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the HVAC wire harness connector
for the mode door actuator to the actuator connector
receptacle.
(4) Reinstall the silencer under the driver side end
of the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/INSTRUMENT PANEL
SILENCER - INSTALLATION).
(5) Reconnect the battery negative cable.
(6) Perform the heater-A/C control calibration pro-
cedure. (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS - FRONT/A/C-HEATER CONTROL
- STANDARD PROCEDURE - HEATER-A/C CON-
TROL CALIBRATION).
POWER MODULE
DESCRIPTION
A blower power module is used on this model when
it is equipped with the optional Automatic Tempera-
ture Control (ATC) (Fig. 22). Models equipped with
the standard manual heater-A/C control use a blower
motor resistor, instead of the blower power module.
The blower power module is installed in a mounting
hole in the evaporator housing, directly behind the
glove box opening of the instrument panel. The mod-
ule consists of a molded plastic mounting plate with
two integral connector receptacles. Concealed behind
the mounting plate within the evaporator housing is
the power module electronic circuitry and a large
finned, heat sink. The module mounting plate is
secured with two screws to the evaporator housingand is accessed for service by rolling down the glove
box from the instrument panel.
The power module heat sink will get hot when in
use. Do not touch the heat sink if the blower motor
has been running. The blower power module cannot
be adjusted or repaired and, if faulty or damaged, it
must be replaced.
OPERATION
The blower power module is connected to the vehi-
cle electrical system through a dedicated take out
and connector of the instrument panel wire harness.
A second connector receptacle receives the pigtail
wire connector from the blower motor. The blower
power module allows the microprocessor-based Auto-
matic Temperature Control (ATC) heater-A/C control
module to calculate and provide infinitely variable
blower motor speeds based upon either manual
blower switch input or the ATC programming using a
Pulse Width Modulated (PWM) circuit strategy. The
PWM voltage is applied to a comparator circuit
which compares the PWM signal voltage to the
blower motor feedback voltage. The resulting output
drives the power module circuitry, which adjusts the
voltage output received from the blower motor relay
to change or maintain the desired blower speed. The
blower power module is diagnosed using a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
REMOVAL
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) Disconnect and isolate the battery negative
cable.
(2) Open the glove box.
(3) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box downward.
(4) Reach through the glove box opening to access
and disconnect the instrument panel wire harness
Fig. 22 Power Module
1 - POWER MODULE
2 - LOWER GLOVE BOX OPENING REINFORCEMENT
3 - EVAPORATOR HOUSING
24 - 26 CONTROLS - FRONTRS
MODE DOOR ACTUATOR (Continued)
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