2005 CHRYSLER VOYAGER heating

Condition Possible Causes Correction
The low side pressure is too
low, and the high side
pressure is too high.1. Restricted refrigerant flow
through the refrigerant lines.1. See Liquid Line, Suction Line and Discharge
Line in this group. Inspect the refrigerant lines for
kinks, tight bends or improper routing. Correct
the routing or replace the refrigerant line, if
required.
2. Restricted refrigerant flow
through the A/C expansion
valve.2. See A/C Expansion Valve in this group.
Replace the valve, if required.
3. Restricted refrigerant flow
through the A/C condenser.3. See A/C Condenser in this group. Replace the
restricted condenser, if required.
HEATER PERFORMANCE TEST
WARNING: REVIEW SAFETY PRECAUTIONS AND
WARNINGS IN THIS GROUP BEFORE PERFORMING
THIS PROCEDURE (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNING).
Check the coolant level, drive belt tension, radiator
air flow and fan operation. Start engine and allow to
warm up to normal operating temperature.
WARNING: DO NOT REMOVE RADIATOR CAP
WHEN ENGINE IS HOT, PERSONAL INJURY CAN
RESULT.
If vehicle has been run recently, wait 15 minutes
before removing the radiator cap. Place a rag overthe cap and turn it to the first safety stop. Allow
pressure to escape through the overflow tube. When
the system pressure stabilizes, remove the cap com-
pletely.
MAXIMUM HEATER OUTPUT: TEST AND ACTION
Engine coolant is provided to the heater system by
two heater hoses. With the engine idling at normal
operating temperature, set the temperature control
to maximum heat, the mode control to the floor posi-
tion, and the blower in the highest speed position.
Using a test thermometer, check the temperature of
the air being discharged from the floor outlets. Com-
pare the test thermometer reading to the Tempera-
ture Reference chart.
TEMPERATURE REFERENCE
Ambient Temperature Minimum Floor Outlet Temperature
Celsius Fahrenheit Celsius Fahrenheit
15.5É 60É 62.2É 144É
21.1É 70É 63.8É 147É
26.6É 80É 65.5É 150É
32.2É 90É 67.2É 153É
If the floor outlet air temperature is insufficient,
check that the cooling system is operating to specifi-
cations (Refer to 7 - COOLING/ENGINE - DIAGNO-
SIS AND TESTING). Both heater hoses should be
HOT to the touch (the coolant return hose should be
slightly cooler than the supply hose). If the coolant
return hose is much cooler than the supply hose,
locate and repair the engine coolant flow obstruction
in heater system.
OBSTRUCTED COOLANT FLOW Possible locations or causes
of obstructed coolant flow are as follows:
²Pinched or kinked heater hoses.
²Improper heater hose routing.²Plugged heater hoses or supply and return ports
at the cooling system connections.
²Plugged heater core.
If proper coolant flow through the cooling system is
verified, and heater outlet air temperature is insuffi-
cient, a mechanical problem may exist.
MECHANICAL PROBLEMS
Possible causes of insufficient heat due to mechan-
ical problems are as follows:
²Obstructed cowl air intake.
²Obstructed heater system outlets.
²Blend door not functioning properly.
24 - 10 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

TEMPERATURE CONTROL
If the heater outlet air temperature cannot be
adjusted with the temperature control knob on the
A/C-heater control panel, the following could require
service:
²Blend door binding.
²Faulty blend door actuator.
²Faulty A/C-heater control.
²Faulty related wiring harness or connectors.²Improper engine coolant temperature.
SPECIFICATIONS
A/C SYSTEM
The R-134a refrigerant system charge capacity for
this vehicle can be found on the underhood Specifica-
tion Label.
SYSTEM SPECIFICATIONS
Item Description Notes
A/C Compressor Denso 10S17 ± 2.4L/2.5L/2.8L/3.3L
without rear A/C
Denso 10S20 ± 3.3L/3.8L with rear
A/CND-8 PAG Oil
Freeze±up Control Evaporator temperature sensor HVAC housing mounted (RS models),
Evaporator mounted (RG models) - input to
A/C-heater control module
Low PSI Control A/C pressure transducer Liquid line mounted - input to Powertrain Control
Module (PCM) - PCM opens compressor clutch
relay above 200 kPa (29 psi)
High PSI Control A/C pressure transducer Liquid line mounted - input to PCM - PCM
opens compressor clutch relay below 3100 kPa
(450 psi)
High Pressure relief valve Compressor mounted - opens above 3445-4135
kPa (500-600 psi), closes below 2756 kPa (400
psi)
Compressor Clutch Coil
DrawDenso 10S17 ± 3.3 amps @ 12V  
0.5V @ 21É C (70É F)
Denso 10S20 ± 2.2 amps @ 12V  
0.5V @ 21É C (70É F)
Compressor Clutch Air
Gap0.35 - 0.60 mm (0.014 - 0.024 in.)
TORQUE SPECIFICATIONS
Description N´m Ft. Lbs. In. Lbs.
A/C Compressor Shaft Bolt 17.5 ± 155
A/C Compressor Mounting Bolts (2.4L/2.5L/2.8L) 28 21 ±
A/C Compressor Mounting Bolts (3.3L/3.8L) 54 40 ±
A/C Compressor Mounting Bracket Bolts (2.4L) 54 40 ±
A/C Condenser Mounting Bracket Screws 5 ± 45
A/C Expansion Valve Screws 11 ± 97
A/C-Heater Control Screws 2 ± 17
Blend Door Actuator Screws 2 ± 17
Blower Motor Screws 2 ± 17
Blower Motor Power Module Screws (ATC) 2 ± 17
Blower Motor Resistor Block Screws (MTC) 2 ± 17
Center Bezel Outlet Screws 2 ± 17
RSHEATING & AIR CONDITIONING24-11
HEATING & AIR CONDITIONING (Continued)

Description N´m Ft. Lbs. In. Lbs.
Distribution Housing Screws 2 ± 17
Discharge Line to Compressor Nut 23 17 ±
Discharge Line to Condenser Nut 23 17 ±
Front Fascia Screws 6 ± 53
Front Fascia Grille Insert Screws 2 ± 17
Heater Core Mounting Plate Screws 2 ± 17
Heater Core Sealing Plate Screws 3 ± 26
Hood Latch Screws 14 ± 123
HVAC Housing Bracket Bolt 3 ± 26
HVAC Housing Mounting Nuts 7 ± 62
HVAC Housing Mounting Bolts 4 ± 35
Liquid Line to Condenser Nut 23 17 ±
Liquid Line to Receiver/drier Bolt 11 ± 97
Lower Air inlet Housing Screws 2 ± 17
Mode Door Actuator Screws 2 ± 17
Quarter Trim Panel Attaching Bracket Screws 2 ± 17
Rear Blower Motor Screws 2 ± 17
Rear Blower Motor Power Module Screws (ATC) 2 ± 17
Rear Blower Motor Resistor Block Screws (MTC) 2 ± 17
Rear Capture Plate Screw 2 ± 17
Rear Evaporator Line Seal Plate to Rear Expansion
Valve Nut23 17 ±
Rear Expansion Valve Bracket Nut 23 17 ±
Rear Expansion Valve Bracket Screws 2 ± 17
Rear Expansion Valve to Rear Evaporator Screws 11 ± 97
Rear Floor Heat Duct Screws 2 ± 17
Rear HVAC Housing Screws 2 ± 17
Rear HVAC Housing Mounting Screws 11 ± 97
Rear HVAC Housing Stud Nuts 9 ± 80
Rear Mode Door Actuator Screws 2 ± 17
Receiver/drier Bracket Nuts 10 ± 89
Recirculation Door Actuator Screws 2 ± 17
Refrigerant Lines to Expansion Valve Nut 23 17 ±
Suction Line to Compressor Nut 23 17 ±
Cabin Heater Air Intake Pipe Screws 7 ± 62
Cabin Heater M6 Bolts 7 ± 62
Cabin Heater M8 Bolts 23 17 ±
Cabin Heater Seat Hex Nut 60 44 ±
Underbody Liquid Line Fitting 23 17 ±
Underbody Refrigerant Line Sealing Plate Bolt/Nut 23 17 ±
Underbody Suction Line Fitting 23 17 ±
Upper Air Inlet Housing Screws 2 ± 17
24 - 12 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

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 for automatic temperature
control (ATC) system or on the HVAC housing for
manual temperature control (MTC) system, the Pow-
ertrain Control Module (PCM) in the engine compart-
ment, and the compressor clutch relay in the
Integrated Power Module (IPM). The PCM may delay
compressor clutch engagement for up to thirty sec-
onds (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/POWERTRAIN CONTROL
MODULE - DESCRIPTION - PCM OPERATION).
DIAGNOSIS AND TESTING
A/C COMPRESSOR CLUTCH COIL
The air conditioning compressor clutch coil electri-
cal circuit is controlled by the powertrain control
module (PCM) through the A/C compressor clutch
relay, which is located in the integrated power mod-
ule (IPM) in the engine compartment. Begin testing
of a suspected compressor clutch coil problem by per-
forming the preliminary checks.
PRELIMINARY CHECKS
(1) If the compressor clutch will not engage, verify
the refrigerant charge level (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING - FRONT/RE-
FRIGERANT - DIAGNOSIS AND TESTING -
REFRIGERANT CHARGE LEVEL). If the refriger-
ant charge level is OK, go to Step 2. If the refriger-
ant charge level is not OK, adjust the refrigerant
charge as required.
(2) If the A/C compressor clutch still will not
engage, disconnect the wire harness connector for the
A/C pressure transducer and check for battery cur-
rent at the connector with the engine running and
the A/C-heater control set to the A/C mode. If OK, go
to TESTS. If not OK, refer to Body Diagnostic Proce-
dures to perform further diagnosis.
TESTS
(1) Verify the battery state of charge (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM/BATTERY -
DIAGNOSIS AND TESTING).
(2) Connect an ammeter (0 to 10 ampere scale
selected) in series with the clutch coil feed terminal.
Connect a voltmeter (0 to 20 volt scale selected) to
measure voltage across the battery and the clutch
coil.
(3) With the heater-A/C control in the A/C mode
and the blower at low speed, start the engine and
allow it to run at a normal idle speed.
(4) The compressor clutch should engage immedi-
ately, and the clutch coil voltage should be within
two volts of the battery voltage. If the coil voltage is
not within two volts of battery voltage, test the
clutch coil feed circuit for excessive voltage drop. If
the compressor clutch does not engage, refer to Body
Diagnostic Procedures to perform further diagnosis.
(5) For the acceptable A/C clutch coil current draw
specificationsrefer to 24 - HEATING & AIR CONDI-
TIONING - SPECIFICATIONS. Specifications apply
for a work area temperature of 21É C (70É F). If volt-
age is more than 12.5 volts, add electrical loads by
turning on electrical accessories until voltage reads
below 12.5 volts.
(a) If the compressor clutch coil current reading
is zero, the coil is open and must be replaced.
Fig. 1 A/C Compressor Clutch
1 - BOLT
2 - CLUTCH PLATE
3 - PULLEY AND BEARING
4 - FIELD COIL
5 - SNAP RING (2)
6 - SHIM
24 - 14 CONTROLS - FRONTRS
A/C COMPRESSOR CLUTCH/COIL (Continued)

BLEND DOOR ACTUATOR
DESCRIPTION
The blend door actuators are reversible, 12-volt
Direct Current (DC), servo motors. Models with the
single zone heater and air conditioner system have a
single blend air door, which is controlled by a single
blend door actuator. Models with the optional dual
zone front heater and air conditioner system have
dual blend air doors, which are controlled by two
blend door actuators. The single zone blend door
actuator is located on the driver's side end of the
HVAC housing, close to the middle of the distribution
housing. In the dual zone system, the same blend
door actuator used for the single zone system
becomes the passenger blend door actuator, and is
mechanically connected to only the passenger side
blend air door. In the dual zone system, a second sep-
arate blend door actuator is also located on the
driver side end of the HVAC housing, close to the
middle of the distribution housing, and is mechani-
cally connected to only the driver's side blend air
door.
The blend door actuators are interchangeable with
each other, as well as with the actuators for the
mode door and the recirculation air door. Each actua-
tor 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 distri-
bution housing. Each actuator also has an identical
output shaft with splines that connects it to the link-
age that drives the proper blend air door. The blend
door actuators do not require mechanical indexing to
the blend door linkage, as they are electronically cal-
ibrated by the heater-A/C control module.
OPERATION
The blend door actuators are connected to the A/C-
heater control through the vehicle electrical system
by a dedicated two-wire lead and connector of the
HVAC wire harness. The blend door actuator(s) can
move the blend-air door(s) in two directions. When
the A/C-heater control pulls the voltage on one side
of the motor connection high and the other connec-
tion low, the blend-air door will move in one direc-
tion. When the A/C-heater control reverses the
polarity of the voltage to the motor, the blend-air
door moves in the opposite direction.
When the A/C-heater control makes the voltage to
both connections high or both connections low, the
blend-air door stops and will not move. The A/C-
heater control uses a feedback signal positioning sys-
tem to monitor the operation and relative position of
the blend door actuator(s) and the blend-air door(s).
The A/C-heater control learns the blend-air door stoppositions during the calibration procedure and will
store a diagnostic trouble code (DTC) for any prob-
lems it detects in the blend door actuator circuits.
The blend door actuators are diagnosed using a
scan tool (Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING and to 24 -
HVAC Electrical Diagnostics for more information).
The blend door actuators cannot be adjusted or
repaired and, if faulty or damaged, they must be
replaced.
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.
NOTE: The single zone heating and air conditioning
system is equipped with a single blend door actua-
tor. 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 procedures can be used for each of
these actuators.
(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) Disconnect the wire harness connector from the
blend door actuator(s) (Fig. 11).
(4) Remove the two screws that secure the blend
door actuator to the distribution housing.
(5) Remove the blend door actuator.
INSTALLATION
(1) Position the blend door actuator onto the distri-
bution 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 the two screws that secure the blend
door actuator to the housing. Tighten the screws to 2
N´m (17 in. lbs.).
24 - 22 CONTROLS - FRONTRS

(3) Connect the HVAC wire harness connector to
the blend door actuator.
(4) Install the silencer under the driver side end of
the instrument panel (Refer to 23 - BODY/INSTRU-
MENT 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).
BLOWER MOTOR RELAY
DESCRIPTION
The front blower motor relay is an International
Standards Organization (ISO)-type relay (Fig. 12).
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The front
blower motor relay is located in the integrated power
module (IPM) in the engine compartment. See the
fuse and relay map on the inner surface of the cover
of the IPM for front blower motor relay identification
and location.
The black, molded plastic case is the most visible
component of the front blower motor relay. Five male
spade-type terminals extend from the bottom of the
base to connect the relay to the vehicle electrical sys-
tem, and the ISO designation for each terminal ismolded into the base adjacent to each terminal. The
ISO terminal designations are as follows:
²30 (Common Feed)- This terminal is con-
nected to the movable contact point of the relay.
²85 (Coil Ground)- This terminal is connected
to the ground feed side of the relay control coil.
²86 (Coil Battery)- This terminal is connected
to the battery feed side of the relay control coil.
²87 (Normally Open)- This terminal is con-
nected to the normally open fixed contact point of the
relay.
²87A (Normally Closed)- This terminal is con-
nected to the normally closed fixed contact point of
the relay.
The front blower motor relay cannot be adjusted or
repaired. If the relay is damaged or faulty, it must be
replaced.
OPERATION
The blower motor relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control the high current
output to the blower motor resistor (manual heater-
A/C control) or blower power module (ATC control).
The movable common feed contact point is held
against the fixed normally closed contact point by
spring pressure. When the relay coil is energized, an
electromagnetic field is produced by the coil wind-
ings. This electromagnetic field draws the movable
relay contact point away from the fixed normally
closed contact point, and holds it against the fixed
normally open contact point. When the relay coil is
de-energized, spring pressure returns the movable
contact point back against the fixed normally closed
contact point. The resistor or diode is connected in
parallel with the relay coil in the relay, and helps to
dissipate voltage spikes and electromagnetic interfer-
ence that can be generated as the electromagnetic
field of the relay coil collapses.
Fig. 11 Blend Door Actuator - LHD Shown, RHD
Typical
1 - WIRE HARNESS CONNECTOR
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - DRIVER BLEND DOOR ACTUATOR (DUAL-ZONE)
5 - HEATER CORE
6 - BLEND DOOR ACTUATOR (SINGLE ZONE) OR PASSENGER
BLEND DOOR ACTUATOR (DUAL-ZONE)
Fig. 12 Front Blower Motor Relay
RSCONTROLS - FRONT24-23
BLEND DOOR ACTUATOR (Continued)

The blower motor relay terminals are connected to
the vehicle electrical system through a receptacle in
the Integrated Power Module (IPM). The inputs and
outputs of the blower motor relay include:
²The common feed terminal (30) receives a bat-
tery current input from the battery through a B(+)
circuit at all times.
²The coil ground terminal (85) receives a ground
input through the front/rear blower motor relay con-
trol circuit only when the FCM electronically pulls
the control circuit to ground.
²The coil battery terminal (86) receives a battery
current input from the battery through a B(+) circuit
at all times.
²The normally open terminal (87) provides a bat-
tery current output to the blower motor resistor
(manual heater-A/C control) or blower power module
(automatic heater-A/C control) through a fuse in the
IPM on the fused front blower motor relay output cir-
cuit only when the blower motor relay coil is ener-
gized.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
a battery current output only when the blower motor
relay coil is de-energized.
Refer to the appropriate wiring information for
diagnosis and testing of the micro-relay and for com-
plete HVAC wiring diagrams.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the cover from the integrated power
module (IPM) (Fig. 13).
NOTE: Refer to the fuse and relay map on the inner
surface of the cover of the IPM for front blower
motor relay identification and location.
(3) Remove the front blower motor relay from the
IPM
INSTALLATION
NOTE: Refer to the fuse and relay map on the inner
surface of the cover of the integrated power module
(IPM) for front blower motor relay identification and
location.
(1) Position the front blower motor relay to the
proper receptacle in the IPM.
(2) Align the front blower motor relay terminals
with the terminal cavities in the IPM receptacle.
(3) Push down firmly on the front blower motor
relay until the terminals are fully seated in the ter-
minal cavities.
(4) Install the cover onto the IPM.(5) Reconnect the negative battery cable.
BLOWER MOTOR RESISTOR
BLOCK
DESCRIPTION
A blower motor resistor is used on this model when
it is equipped with the manual heater-A/C system.
Models equipped with the optional Automatic Tem-
perature Control (ATC) system use a blower power
module, instead of the blower motor resistor block
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS/POWER MODULE - DESCRIPTION).
The blower motor resistor block is mounted to the
rear of the HVAC housing, directly behind the glove
box opening in the instrument panel. The resistor
block consists of a molded plastic mounting plate
with two integral connector receptacles. Concealed
behind the mounting plate are four coiled resistor
wires contained within a protective stamped steel
cage. The blower motor resistor block is accessed for
service by removing the glove box from the instru-
ment panel.
OPERATION
The blower motor resistor block is connected to the
vehicle electrical system through a dedicated take
out and connector of the instrument panel wire har-
ness. A second connector receptacle receives the pig-
tail wire connector from the blower motor. The
blower motor resistor has multiple resistor wires,
Fig. 13 Front Blower Motor Relay
1 - INTEGRATED POWER MODULE (IPM)
2 - FRONT BLOWER MOTOR RELAY
2 - FRONT CONTROL MODULE (FCM)
24 - 24 CONTROLS - FRONTRS
BLOWER MOTOR RELAY (Continued)

(8) Run the HVAC Cool Down test to verify system
is operating properly (Refer to 24 - HEATING & AIR
CONDITIONING - DIAGNOSIS AND TESTING).
RS MODELS
(1) Install the evaporator temperature sensor into
the top of the HVAC housing.
(2) Connect the wire harness connector to the
evaporator temperature sensor.
(3) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
(4) Reconnect the negative battery 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. 19). These sensors are used only on mod-
els equipped with the optional automatic tempera-
ture control (ATC) heating-A/C 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 harness routedbehind the center bezel connects the sensors directly
to the ATC A/C-heater control module near the bot-
tom 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
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 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 Body Diagnostic Procedures.
Fig. 18 Evaporator Temperature Sensor - RS Models
1 - EVAPORATOR TEMPERATURE SENSOR
2 - WIRE HARNESS CONNECTOR
3 - HVAC HOUSING
Fig. 19 Infrared Temperature Sensor ± RS shown,
RG typical
1 - INSTRUMENT PANEL CENTER BEZEL
2 - CENTER IP AIR OUTLETS
3 - INFRARED TEMPERATURE SENSOR
24 - 28 CONTROLS - FRONTRS
EVAPORATOR TEMPERATURE SENSOR (Continued)