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 push-in plastic
retainer allows the sensor to be removed or installed
from the expansion valve without disturbing the
refrigerant in the system. The evaporator tempera-
ture 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.
(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
(Fig. 19).
(4) Install the temperature sensor retaining screw
and tighten.(5) Install the window wiper assembly to the vehi-
cle (REFER to 8 - ELECTRICAL/WIPERS/WASH-
ERS/WIPER MODULE - INSTALLATION).
(6) Reinstall the air cleaner housing into the right
side of the engine compartment.
(7) Reconnect the battery negative cable.
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. 20). 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.
Fig. 20 Infrared Temperature Sensor
1 - INSTRUMENT PANEL CENTER BEZEL
2 - CENTER BEZEL OUTLETS
3 - INFRARED TEMPERATURE SENSOR
24 - 24 CONTROLS - FRONTRS
EVAPORATOR TEMPERATURE SENSOR (Continued)
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 or
evaporative 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. 21). 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
it to the linkage that drives the mode door. The mode
door actuator does not require mechanical indexing
to the mode door linkage, as it is electronically cali-
brated by the heater-A/C control module. The mode
door actuator cannot be adjusted or repaired and, if
damaged or faulty, it must be replaced.
OPERATION
The mode door actuator is connected to the heater-
A/C control module through the vehicle electrical sys-
tem by a dedicated two-wire take out and connector
of the HVAC wire harness. The mode door actuator
can move the mode door in two directions. When the
heater-A/C control module pulls the voltage on one
side of the motor connection high and the other con-
nection low, the mode door will move in one direction.
When the module reverses the polarity of the voltage
to the motor, the mode door moves in the opposite
direction. When the module makes the voltage to
both connections high or both connections low, the
mode door stops and will not move. These same
motor connections also provide a feedback signal to
the heater-A/C control module. This feedback signal
allows the module to monitor the operation and rela-
tive position of the mode door actuator and the mode
door. The heater-A/C control module learns the mode
door stop positions during the calibration procedure
and will store a Diagnostic Trouble Code (DTC) for
any problems it detects in the mode door actuator
circuits. The mode door actuator can be diagnosed
using a DRBIIItscan tool. Refer to the appropriate
diagnostic information.
Fig. 21 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)
RSCONTROLS - FRONT24-25
INFRARED TEMPERATURE SENSOR (Continued)
CONTROLS - REAR
TABLE OF CONTENTS
page page
A/C-HEATER CONTROL
REMOVAL..............................30
INSTALLATION...........................31
BLEND DOOR ACTUATOR
DESCRIPTION...........................31
OPERATION.............................31
REMOVAL..............................32
INSTALLATION...........................32
BLOWER MOTOR RELAY
DESCRIPTION...........................33
OPERATION.............................33
DIAGNOSIS AND TESTING.................34
BLOWER MOTOR RELAY.................34
REMOVAL..............................34
INSTALLATION...........................34
BLOWER MOTOR RESISTOR
DESCRIPTION...........................35
OPERATION.............................35
DIAGNOSIS AND TESTING.................35BLOWER MOTOR RESISTOR.............35
REMOVAL..............................36
INSTALLATION...........................36
EXPANSION VALVE SOLENOID
DESCRIPTION...........................36
OPERATION.............................37
INFRARED TEMPERATURE SENSOR
DESCRIPTION...........................37
OPERATION.............................37
MODE DOOR ACTUATOR
DESCRIPTION...........................37
OPERATION.............................38
REMOVAL..............................38
INSTALLATION...........................38
POWER MODULE
DESCRIPTION...........................39
OPERATION.............................39
REMOVAL..............................40
INSTALLATION...........................40
A/C-HEATER CONTROL
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Using a trim stick or another suitable wide flat
bladed tool, gently pry the top edge of the rear heat-
er-A/C control bezel away from the headliner far
enough to release the two snap clip retainers (Fig. 1).
(3) Pull the rear heater-A/C control and bezel unit
rearward far enough to access the headliner wire
harness connector on the back of the control.
(4) Disconnect the headliner wire harness connec-
tor for the rear heater-A/C control from the control
connector receptacle.
(5) Remove the rear heater-A/C control from the
headliner.
(6) Remove the three screws that secure the rear
heater-A/C control to the bezel (Fig. 2).
(7) Remove the rear heater-A/C control from the
bezel.
Fig. 1 Heater-A/C Control
1 - TRIM STICK
2 - BEZEL
3 - HEATER-A/C CONTROL
4 - HEADLINER
24 - 30 CONTROLS - REARRS
OPERATION
The rear expansion valve solenoid is designed to
control the flow of refrigerant to the rear evaporator.
The solenoid receives fused battery current through
the rear blower motor relay on a fused rear blower
motor relay output circuit, and receives a ground
feed from the front ATC heater-A/C control module
on a TXV solenoid feed circuit. The front ATC heater-
A/C control module is programmed to control solenoid
operation. When the solenoid blocks refrigerant flow
to the rear evaporator, the resulting increase in the
refrigerant circulation rate between the condenser
and the front evaporator provides improved A/C cool-
ing performance for the front seat occupants. The
solenoid may be diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
INFRARED TEMPERATURE
SENSOR
DESCRIPTION
The rear infrared temperature sensor consists of
an infrared transducer that is concealed behind the
lens of the rear heater-A/C control in the headliner.
This sensor is used only on models equipped with the
optional Automatic Temperature Control (ATC) heat-
ing and air conditioning system. The rear infrared
temperature sensor is integral to the rear heater-A/C
control. The infrared sensor cannot be adjusted orrepaired and, if faulty or damaged, the rear heater-
A/C control unit must be replaced.
OPERATION
The rear infrared temperature sensor provides an
independent measurement input to the Automatic
Temperature Control (ATC) heater-A/C control mod-
ule that indicates the surface temperature of the rear
seat occupants. By using a surface temperature mea-
surement, rather than an air temperature measure-
ment, the ATC system is able to adjust itself to the
comfort level as perceived by the occupant. This
allows the system to detect and compensate for other
ambient conditions affecting comfort levels, such as
solar heat gain or evaporative heat loss. The ATC
system logic responds to the infrared sensor input by
calculating and adjusting the air flow temperature
and air flow rate needed to properly obtain and
maintain the selected comfort level temperatures for
the rear seat occupants. The ATC heater-A/C control
module continually monitors the infrared sensor cir-
cuit, 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
Fig. 9 Expansion Valve Solenoid
1 - SOLENOID
2 - SOLENOID CONNECTOR
3 - SEALING PLATE
4 - EXPANSION VALVE
5 - SEALING PLATE
6 - HVAC CONNECTOR
Fig. 10 Mode Door Actuator
1 - SCREW (2)
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - CONNECTOR
5 - BLEND DOOR ACTUATOR
6 - CONNECTOR
RSCONTROLS - REAR24-37
EXPANSION VALVE SOLENOID (Continued)
(3) With the latch still positioned against its
opened stop, reinstall the air filter door onto the
lower evaporator housing air filter opening (Fig. 2).
(4) Slide the air filter door latch toward the front
of the vehicle until it hits the closed stop on the door.
AIR OUTLETS
DESCRIPTION
Based upon the system mode selected, conditioned
air can exit the front heater-A/C unit housing
through one or a combination of the four main hous-
ing outlets: defrost, demist, panel, or floor. Once the
conditioned air exits the unit housing, it is directed
through molded plastic ducts to the various outlets in
the vehicle interior. These outlets and their locations
are as follows:
²Defroster Outlet- A single, centrally mounted
outlet delivers air for defrosting the large windshield.
Because outlet vanes are not needed to direct flow, a
simple, integral grid is molded into the center of the
instrument panel top cover to prevent objects from
falling into the duct. If the defroster outlet is faulty
or damaged, the instrument panel top cover must be
replaced.
²Demister Outlets- There are two side window
demisters that aid in defogging and defrosting the
front door windows. One demister outlet is located at
each outboard end of the instrument panel top pad,
near the belt line at the A-pillars. The demister out-
lets can be removed from the top pad individually for
service replacement.²Instrument Panel Outlets- There are five
panel outlets in the instrument panel, one located
near each outboard end of the instrument panel fac-
ing the rear of the vehicle, and three located near the
top of the instrument panel center bezel. On models
with manual temperature control, all five of these
outlets are fully adjustable. On models with Auto-
matic Temperature Control (ATC), the center outlet
in the center bezel has fixed vanes because it also
houses the remote infrared temperature sensors for
the front seat positions. The outboard outlets can be
removed individually for service replacement. The
center bezel outlets are serviced as a gang of three
outlets and, on models with ATC, also includes the
infrared sensors.
²Front Door Rear Outlets- A fully adjustable
outlet located at the rear of each front door trim
panel supplies only cooled air to the intermediate
seat passengers. Air is supplied to these outlets from
the instrument panel through ducts in the doors that
use molded seals at the instrument panel to prevent
air leakage. The door ducts are integral to the front
door trim panels. These outlets also incorporate a red
reflector to improve the safety and visibility of an
opened front door to traffic approaching the vehicle
from the rear at night. These outlets can be removed
from the door trim panels for service replacement.
²Front Floor Outlets- There are two front floor
outlets, one located above each side of the floor panel
center tunnel below the instrument panel. These out-
lets are integral to the front heater-A/C unit distri-
bution housing.
²Rear Floor Outlets- Wide rear floor outlets
located under each front seat have integral, fixed
directional dividers to distribute heated air across
the floor for intermediate seat passengers. These out-
lets are integral to the floor distribution ducts routed
under the front floor carpet from an outlet nozzle on
the bottom of the front heater-A/C unit distribution
housing.
REMOVAL - CENTER BEZEL OUTLETS
The three outlets located near the top of the
instrument panel center bezel are serviced only as a
gang of all three outlets. If the vehicle is equipped
with the optional Automatic Temperature Control
(ATC) system, the center outlet of the three has fixed
vanes and also houses the remote front infrared tem-
perature sensors.
Fig. 2 Air Filter Door
1 - AIR FILTER DOOR
2-LATCH
3 - CLOSED STOP
4 - LOWER EVAPORATOR HOUSING
5 - OPENED STOP
24 - 42 DISTRIBUTION - FRONTRS
AIR FILTER (Continued)
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 center bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL).
(3) Place the center bezel face down on a suitable
work surface. Be certain to take the proper precau-
tions to protect the face of the center bezel from cos-
metic damage.
(4) If the vehicle is equipped with the optional
ATC system, disconnect the ATC remote infrared
temperature sensor jumper harness from the sensor
connector receptacle located on the bottom of the cen-
ter outlet housing (Fig. 3).(5) Remove the three screws that secure the bot-
tom of the outlet housing to the center bezel.
(6) Roll the bottom of the outlet housing upwards
towards the top of the center bezel far enough to dis-
engage the retainer features on the top of the outlet
housing from their receptacles at the top of the cen-
ter bezel.
(7) Remove the center bezel outlets and housing
from the center bezel as a unit.
REMOVAL - DEMISTER OUTLET
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the outer perimeter of the
demister outlet away from the instrument panel top
pad until the snap features on the outlet are released
(Fig. 4).
(2) Remove the demister outlet from the demister
duct opening in the instrument panel top pad.
REMOVAL - FRONT DOOR REAR OUTLET
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim panel from the front door
inner panel. (Refer to 23 - BODY/DOOR - FRONT/
TRIM PANEL - REMOVAL).
(3) Using a trim stick or another suitable wide
flat-bladed tool, depress the four latch features (two
top and two bottom) that secure the outlet to the
inside of the trim panel rear outlet opening and push
the outlet unit out through the opening (Fig. 5).
(4) Remove the front door rear outlet through the
outside of the front door trim panel outlet opening.
Fig. 3 Center Bezel Outlets
1 - CENTER BEZEL
2 - CENTER BEZEL OUTLETS
3 - SCREW (3)
4 - INSTRUMENT PANEL SWITCH BANK
5 - CONNECTOR (ATC ONLY)
6 - JUMPER HARHESS (ATC ONLY)
Fig. 4 Demister Outlet
1 - DEMISTER OUTLET
2 - INSTRUMENT PANEL TOP PAD
3 - TRIM STICK
RSDISTRIBUTION - FRONT24-43
AIR OUTLETS (Continued)
REMOVAL - INSTRUMENT PANEL OUTLET
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the outer perimeter of the
instrument panel outlet away from the instrument
panel top pad until the snap features on the outlet
are released (Fig. 6).
(2) Remove the instrument panel outlet from the
panel duct opening in the instrument panel top pad.
INSTALLATION - CENTER BEZEL OUTLETS
(1) Position the center bezel outlets and housing
onto the center bezel as a unit (Fig. 3).
(2) Engage the retainer features on the top of the
outlet housing with their receptacles at the top of the
center bezel, then roll the bottom of the outlet hous-
ing downwards towards the center bezel.
(3) Install and tighten the three screws that secure
the bottom of the outlet housing to the center bezel.
Tighten the screws to 2 N´m (17 in. lbs.).
(4) If the vehicle is equipped with the optional
ATC system, reconnect the ATC remote infrared tem-
perature sensor jumper harness to the sensor connec-
tor receptacle located on the bottom of the center
outlet housing.
(5) Reinstall the center bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - INSTAL-
LATION).
(6) Reconnect the battery negative cable.
INSTALLATION - DEMISTER OUTLET
(1) Position the demister outlet over the demister
duct opening in the instrument panel top pad (Fig.
4).
(2) Using hand pressure, press the demister outlet
firmly and evenly into the instrument panel top pad
opening until the snap features on the outlet are
fully engaged.
INSTALLATION - FRONT DOOR REAR OUTLET
(1) Position the front door rear outlet through the
outside of the front door trim panel outlet opening.
(2) While keeping the outlet aligned with the door
duct opening behind the trim panel, use hand pres-
sure to press the outlet firmly and evenly through
the outside of the front door trim panel outlet open-
ing until the four latch features (two top and two bot-
tom) that secure the outlet to the inside of the
opening are fully engaged (Fig. 5).
(3) Reinstall the trim panel onto the front door
inner panel. (Refer to 23 - BODY/DOOR - FRONT/
TRIM PANEL - INSTALLATION).
(4) Reconnect the battery negative cable.
INSTALLATION - INSTRUMENT PANEL OUTLET
(1) Position the instrument panel outlet into the
panel duct opening in the instrument panel top pad
(Fig. 6).
(2) Using hand pressure, press the instrument
panel outlet firmly and evenly into the instrument
panel top pad opening until the snap features on the
outlet are fully engaged.
Fig. 5 Front Door Rear Outlet
1 - FRONT DOOR REAR OUTLET
2 - FRONT DOOR TRIM PANEL
Fig. 6 Instrument Panel Outlet
1 - INSTRUMENT PANEL TOP PAD
2 - INSTRUMENT PANEL OUTLET
3 - TRIM STICK
24 - 44 DISTRIBUTION - FRONTRS
AIR OUTLETS (Continued)
(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.
(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
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
Fig. 11 Upper Intake Air Housing
1 - EVAPORATOR HOUSING
2- UPPER INTAKE AIR HOUSING
3 - RECIRCULATION AIR DOOR
4 - BLOWER WHEEL
24 - 72 PLUMBING - FRONTRS
EVAPORATOR (Continued)