ECU CHRYSLER CARAVAN 2005 Service Manual

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

each of which 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
system 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 resis-
tor wires, increasing the blower motor speed.
The blower motor resistor cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
DIAGNOSIS AND TESTING
FRONT BLOWER MOTOR RESISTOR BLOCK
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.
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, further details on wire
harness routing and retention, as well as pin-out and
location views for the various wire harness connec-
tors, splices and grounds.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the glove box from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - REMOVAL).
(3) Disconnect the two wire harness connectors
from the blower motor resistor block.
(4) Check for continuity between each of the
blower motor switch input terminals of the resistor
and the resistor output terminal. In each case there
should be continuity. If OK, repair the wire harness
circuits between the blower motor switch and the
blower motor resistor, blower motor or blower motorrelay as required. If not OK, replace the faulty
blower motor resistor block.
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
BLOCK MAY GET VERY HOT DURING NORMAL
OPERATION. IF THE BLOWER MOTOR WAS
TURNED ON PRIOR TO SERVICING THE BLOWER
MOTOR RESISTOR BLOCK, WAIT FIVE MINUTES
TO ALLOW THE BLOWER MOTOR RESISTORS TO
COOL BEFORE PERFORMING DIAGNOSIS OR SER-
VICE. FAILURE TO TAKE THIS PRECAUTION 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) Remove the glove box from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - REMOVAL).
(3) Disconnect the two wire harness connectors
from the blower motor resistor block (Fig. 14).
(4) Remove the two screws that secure the blower
motor resistor block to the HVAC housing.
(5) Remove the resistor block from the HVAC
housing.
INSTALLATION
(1) Position the blower motor resistor block into
the HVAC housing.
(2) Install the two screws that secure the blower
motor resistor block to the HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(3) Connect the two wire connectors to the resistor
block.
RSCONTROLS - FRONT24-25
BLOWER MOTOR RESISTOR BLOCK (Continued)

(4) Install the glove box (Refer to 23 - BODY/IN-
STRUMENT PANEL/GLOVE BOX - INSTALLA-
TION).
(5) Reconnect the battery negative cable.
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator temperature sensor used for the
manual and automatic temperature control systems
on RS models is installed on the top of the HVAC
housing behind the instrument panel and measures
the air temperature downstream of the evaporator
(Fig. 15). The sensor is an electrical thermistor in a
plastic housing that is inserted into the HVAC hous-
ing. Two terminals within the molded plastic connec-
tor receptacle on the sensor connect it to the vehicle
electrical system through a take out and connector of
the HVAC wire harness.
The evaporator temperature sensor used for the
manual and automatic temperature control systems
on RG models is installed on the top of the expansion
valve in the right rear corner of the engine compart-
ment and measures the temperature of the evapora-
tor coils (Fig. 16). The sensor has a small probe that
is inserted in a small well in the body of the expan-
sion 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 thesensor connect it to the vehicle electrical system
through a take out and connector of the HVAC wire
harness.
Fig. 14 Blower Motor Resistor Block - Typical
1 - BLOWER MOTOR RESISTOR
2 - INSTRUMENT PANEL WIRE HARNESS
3 - SCREW (2)
4 - GLOVE BOX OPENING REINFORCEMENT
5 - BLOWER MOTOR PIGTAIL WIRE HARNESS
6 - HVAC HOUSING
Fig. 15 Evaporator Temperature Sensor - RS Models
1 - EVAPORATOR TEMPERATURE SENSOR
2 - HVAC HOUSING
3 - A/C EVAPORATOR
Fig. 16 Evaporator Temperature Sensor - RG Models
1 - EVAPORATOR TEMPERATURE SENSOR
2 - A/C EXPANSION VALVE
24 - 26 CONTROLS - FRONTRS
BLOWER MOTOR RESISTOR BLOCK (Continued)

MODE DOOR ACTUATOR
DESCRIPTION
The mode door actuator is a reversible, 12-volt
Direct Current (DC), servo motor. The single mode
door actuator is located on the driver's side end of
the HVAC housing, close to the top of the distribution
housing. The mode door actuator is mechanically con-
nected to the mode door.
The mode door actuator is interchangeable with
the actuators for the blend air door(s) and the recir-
culation 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 distribution 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 electroni-
cally calibrated by the heater-A/C control module.
OPERATION
The mode door actuator is connected to the A/C-
heater control through the vehicle electrical system
by a dedicated two-wire lead and connector from the
HVAC wire harness. The mode door actuator can
move the mode door in two directions. When the A/C-
heater control pulls the voltage on one side of the
motor connection high and the other connection low,
the mode door will move in one direction. When the
A/C-heater control reverses the polarity of the volt-
age to the motor, the mode door moves in the oppo-
site direction. When the A/C-heater control makes
the voltage to both connections high or both connec-
tions low, the mode door stops and will not move.
These same motor connections also provide a feed-
back signal to the A/C-heater control. This feedback
signal allows the A/C-heater control to monitor the
operation and relative position of the mode door
actuator and the mode door. The A/C-heater control
learns the mode door stop positions during the cali-
bration 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 Body Diagnostic Proce-
dures for more information. The mode door actuator
cannot be adjusted or repaired and, if damaged or
faulty, it 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.
(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
mode door actuator (Fig. 20).
(4) Remove the two screws that secure the mode
door actuator to the HVAC distribution housing.
(5) Remove the mode door actuator from the distri-
bution housing.
Fig. 20 Mode 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)
RSCONTROLS - FRONT24-29

INSTALLATION
(1) Position the mode door actuator onto the HVAC
distribution housing. If necessary, rotate the actuator
slightly to align the splines on the actuator output
shaft with those in the mode door linkage.
(2) Install the two screws that secure the mode
door actuator to the distribution housing. Tighten the
screws to 2 N´m (17 in. lbs.).
(3) Connect the wire harness connector to the
mode 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 negative battery cable.
(6) Perform the A/C-heater 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 - BLOWER
MOTOR
DESCRIPTION
A blower motor power module is used on this
model when it is equipped with the optional Auto-
matic Temperature Control (ATC) system. Models
equipped with the standard manual heater-A/C sys-
tem use a blower motor resistor block, instead of the
blower motor power module (Refer to 24 - HEATING
& AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RESISTOR BLOCK - DESCRIPTION).
The blower motor power module is mounted to the
rear of the HVAC housing, directly behind the glove
box opening in the instrument panel. The module
consists of a molded plastic mounting plate with two
integral connector receptacles. Concealed behind the
mounting plate is the power module electronic cir-
cuitry and a large finned, heat sink. The blower
motor power module is accessed for service by remov-
ing the glove box from the instrument panel.
OPERATION
The blower motor power module is connected to the
vehicle electrical system through a dedicated lead
and connector from the instrument panel wire har-
ness. A second connector receptacle receives a wire
lead connector from the blower motor. The blower
motor power module allows the microprocessor-based
Automatic Temperature Control (ATC) heater-A/C
control module to calculate and provide infinitely
variable blower motor speeds based upon either man-
ual blower switch input or the ATC programming
using a Pulse Width Modulated (PWM) circuit strat-
egy. The PWM voltage is applied to a comparator cir-
cuit 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 motor power module is diagnosed using a
DRBIIItscan tool. Refer to Body Diagnostic Proce-
dures.
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 HEAT SINK FOR THE BLOWER
MOTOR POWER MODULE MAY GET VERY HOT
DURING NORMAL OPERATION. IF THE BLOWER
MOTOR WAS TURNED ON PRIOR TO SERVICING
THE BLOWER MOTOR POWER MODULE, WAIT
FIVE MINUTES TO ALLOW THE HEAT SINK TO
COOL BEFORE PERFORMING DIAGNOSIS OR SER-
VICE. FAILURE TO TAKE THIS PRECAUTION CAN
RESULT IN PERSONAL INJURY.
24 - 30 CONTROLS - FRONTRS
MODE DOOR ACTUATOR (Continued)

(1) Disconnect and isolate the negative battery
cable.
(2) Remove the glove box from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - REMOVAL).
(3) Disconnect the two wire harness connectors
from the blower motor power module (Fig. 21).
(4) Remove the two screws that secure the blower
motor power module to the HVAC housing.
(5) Remove the blower motor power module from
the HVAC housing.
INSTALLATION
(1) Position the blower motor power module into
the HVAC housing.
(2) Install the two screws that secure the blower
motor power module to the HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(3) Connect the two wire connectors to the blower
motor power module.
(4) Install the glove box (Refer to 23 - BODY/IN-
STRUMENT PANEL/GLOVE BOX - INSTALLA-
TION).
(5) Reconnect the negative battery cable.
RECIRCULATION DOOR
ACTUATOR
DESCRIPTION
The recirculation door actuator is a reversible,
12-volt direct current (DC), servo motor. The single
recirculation door actuator is located on the passen-
ger side end of the HVAC housing, on the air inlet
housing. The recirculation door actuator is mechani-
cally connected to the recirculation-air door. The
recirculation door actuator is interchangeable with
the actuators for the blend-air door(s) and the mode
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 air inlet housing. Each actuator also has an iden-
tical output shaft with splines that connects it to the
linkage that drives the recirculation-air door. The
recirculation door actuator does not require mechan-
ical indexing to the recirculation-air door, as it is
electronically calibrated by the A/C-heater control.
OPERATION
The recirculation door actuator is connected to the
heater-A/C control module through the vehicle elec-
trical system by a dedicated two-wire lead and con-
nector of the HVAC wire harness. The recirculation
door actuator can move the recirculation-air door in
two directions. When the A/C-heater control pulls the
voltage on one side of the motor connection high and
the other connection low, the recirculation-air door
will move in one direction.
When the A/C-heater control makes the voltage to
both connections high or both connections low, the
recirculation-air door stops and will not move. The
A/C-heater control uses a feedback signal positioning
system to monitor the operation and relative position
of the recirculation door actuator and the recircula-
tion-air door. The A/C-heater control learns the recir-
culation-air door stop positions during the calibration
procedure and will store a diagnostic trouble code
(DTC) for any problems it detects in the recirculation
door actuator circuits.
The recirculation door actuator is 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 recirculation door actuator cannot be adjusted
or repaired and, if faulty or damaged, it must be
replaced.
Fig. 21 Blower Motor Power Module - Typical
1 - POWER MODULE
2 - LOWER GLOVE BOX OPENING REINFORCEMENT
3 - HVAC HOUSING
RSCONTROLS - FRONT24-31
POWER MODULE - BLOWER MOTOR (Continued)

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) Pull the carpet on the passenger side front
floor away from the dash panel far enough to access
the recirculation door actuator.
(3) Disconnect the HVAC wire harness connector
from the recirculation door actuator (Fig. 22).
(4) Remove the two screws that secure the recircu-
lation door actuator to the air inlet housing.
(5) Remove the recirculation door actuator from
the air inlet housing.
INSTALLATION
(1) Position the recirculation door actuator onto
the air intake housing. If necessary, rotate the actua-
tor slightly to align the splines on the actuator out-
put shaft with those in the recirculation air door.
(2) Install the two screws that secure the recircu-
lation door actuator to the air intake housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Connect the HVAC wire harness connector to
the recirculation door actuator.
(4) Reposition the carpet on the passenger side
front floor back up to the dash panel.
(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).
Fig. 22 Recirculation Door Actuator - LHD Shown,
RHD Typical
1 - AIR INLET HOUSING
2 - RECIRCULATION DOOR ACTUATOR
3 - HVAC WIRE HARNESS
4 - SCREW (2)
5 - LOWER HVAC HOUSING
24 - 32 CONTROLS - FRONTRS
RECIRCULATION DOOR ACTUATOR (Continued)

CONTROLS - REAR
TABLE OF CONTENTS
page page
A/C-HEATER CONTROL
DESCRIPTION.........................33
OPERATION...........................33
REMOVAL.............................33
INSTALLATION.........................34
BLEND DOOR ACTUATOR
DESCRIPTION.........................34
OPERATION...........................35
REMOVAL.............................35
INSTALLATION.........................35
BLOWER MOTOR RELAY
DESCRIPTION.........................36
OPERATION...........................36
REMOVAL.............................37
INSTALLATION.........................37
BLOWER MOTOR RESISTOR BLOCK
DESCRIPTION.........................37OPERATION...........................37
DIAGNOSIS AND TESTING
REAR BLOWER MOTOR RESISTOR
BLOCK.............................38
REMOVAL.............................38
INSTALLATION.........................39
MODE DOOR ACTUATOR - REAR
DESCRIPTION.........................39
OPERATION...........................39
REMOVAL.............................39
INSTALLATION.........................40
POWER MODULE - REAR BLOWER MOTOR
DESCRIPTION.........................40
OPERATION...........................40
REMOVAL.............................41
INSTALLATION.........................41
A/C-HEATER CONTROL
DESCRIPTION
The rear heating-A/C system is controlled by rota-
ry-type blower motor and temperature controls, cen-
trally mounted directly into the headliner, or if
equipped with the available DVD player, located in
the player housing. The rear A/C-heater control
allows selection of three blower motor speeds and an
Off position when the center knob on the front A/C-
heater control is set to the Rear position, otherwise
the front unit controls both front and rear heater-A/C
operation.
OPERATION
With the rear A/C-heater control active, tempera-
ture selection dictates the air distribution mode (floor
or overhead air) of the rear unit. A cool temperature
setting directs flow to the overhead outlets and a
warm temperature setting to the floor. Refer to Body
Diagnostic Procedures for further diagnostic informa-
tion.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) If the rear A/C-heater control is mounted in the
headliner, use a trim stick or another suitable wide
flat bladed tool and gently pry the top edge of the
control bezel away from the headliner far enough to
release the two snap clip retainers (Fig. 1).
(3) Pull the rear A/C-heater control and bezel
assembly rearward far enough to access the wire har-
ness connector on the back of the control.
(4) Disconnect the wire harness connector from the
rear A/C-heater control.
(5) Remove the rear A/C-heater control and bezel
assembly from the headliner.
(6) If the rear A/C-heater control is mounted in the
video screen housing, remove the housing from the
headliner (Refer to 8 - ELECTRICAL/AUDIO/VIDEO
SCREEN - REMOVAL).
(7) Remove the three screws that secure the rear
A/C-heater control to the bezel or video screen hous-
ing, depending on application and remove the control
(Fig. 2).
RSCONTROLS - REAR24-33

INSTALLATION
(1) Position the rear A/C-heater control onto the
bezel or video screen housing, depending on applica-
tion.
(2) Install the three screws that secure the rear
A/C-heater control to the bezel or video screen hous-
ing. Tighten the screws to 2 N´m (17 in. lbs.).(3) If the rear A/C-heater control is to be mounted
into the headliner, position the rear A/C-heater con-
trol near the headliner and connect the wire harness
connector to the rear of the control.
(4) Insert the locator tabs on the back of the rear
control bezel over the forward edge of the headliner
opening.
(5) Slide the rear A/C-heater control bezel forward
far enough to align the snap clips on the bezel with
the receptacles on the headliner and by using hand
pressure, press the top edge of the bezel upward
until the two snap clips fully seat into their recepta-
cles.
(6) If the rear A/C-heater control is mounted to the
video screen housing, install the video screen to the
headliner (Refer to 8 - ELECTRICAL/AUDIO/VIDEO
SCREEN - INSTALLATION).
(7) Reconnect the negative battery cable.
(8) Using the DRB-IIItscan tool, reset the Rear
Temperature Selector calibration values.
(9) Verify that the Actuator Calibration of the
Front Control has passed. If an Actuator Calibration
has not passed correct any errors before proceeding
further.
(10) Rotate the Rear Temperature Selector counter
clockwise to the Cold Position, allow the Selector to
remain in the Cold Position for 5 seconds.
(11) Rotate the Rear Temperature Selector Clock-
wise to the Hot Position, allow the Selector to remain
in the Cold Position for 5 seconds.
(12) Calibration is now complete.
BLEND DOOR ACTUATOR
DESCRIPTION
The rear blend door actuator is a reversible,
12-volt Direct Current (DC), servo motor. The single
blend door actuator is located on the outboard side of
the rear HVAC housing, below the mode door actua-
tor. The blend door actuator is mechanically con-
nected to the blend air door.
The rear blend door actuator is interchangeable
with the actuator for the mode 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 rear HVAC housing.
Each actuator also has an identical output shaft with
splines that connects it to the pivot or linkage of the
proper door. The rear blend door actuator does not
require mechanical indexing to the blend air door
pivot, as it is electronically calibrated by the front
heater-A/C control module.
Fig. 1 A/C-Heater Control - Rear
1 - TRIM STICK
2 - BEZEL
3 - REAR A/C-HEATER CONTROL
4 - HEADLINER
Fig. 2 Heater-A/C Control Bezel
1 - BEZEL/VIDEO SCREEN HOUSING (AS EQUIPPED)
2 - SNAP CLIP (2)
3 - REAR A/C-HEATER CONTROL
4 - SCREW (3)
5 - BEZEL LOCATOR TAB (2)
24 - 34 CONTROLS - REARRS
A/C-HEATER CONTROL (Continued)

OPERATION
The rear blend door actuator is connected to the
front heater-A/C control module through the vehicle
electrical system by a dedicated two-wire take out
and connector of the rear HVAC wire harness. The
blend door actuator can move the blend air door in
two directions. When the front heater-A/C control
module pulls the voltage on one side of the motor
connection high and the other connection low, the
blend air door will move in one direction. When the
module reverses the polarity of the voltage to the
motor, the blend air door moves in the opposite direc-
tion. When the module makes the voltage to both
connections high or both connections low, the blend
air door stops and will not move. These same motor
connections also provide a feedback signal to the
front heater-A/C control module. This feedback signal
allows the module to monitor the operation and rela-
tive positions of the blend door actuator and the
blend air door. The front heater-A/C control module
learns the blend air door stop positions during the
calibration procedure and will store a Diagnostic
Trouble Code (DTC) for any problems it detects in
the blend door actuator circuits.
The rear blend door actuator can be diagnosed
using a DRBIIItscan tool. Refer to Body Diagnostic
Procedures for more information. The rear blend door
actuator cannot be adjusted or repaired and, if dam-
aged or faulty, it must be replaced.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the right quarter trim panel and right
D-pillar trim panel from the quarter inner panel
(Refer to 23 - BODY/INTERIOR/QUARTER TRIM
PANEL - REMOVAL).
(3) Remove the two screws that secure the top of
the quarter trim panel attaching bracket to the quar-
ter inner panel.
(4) Remove the screw that secures the back of the
rear HVAC housing to the right D-pillar.
(5) Remove the screw that secures the front of the
rear HVAC housing to the right quarter inner panel.
(6) Carefully pull the top of the rear HVAC hous-
ing away from the right quarter inner panel far
enough to reach between the rear HVAC housing and
the quarter inner panel to access the blend door
actuator (Fig. 3).
(7) Remove the two screws that secure the blend
door actuator to the rear HVAC housing.
(8) Pull the blend door actuator away from the
rear HVAC housing far enough to disengage the
actuator output shaft from the rear blend door pivot.(9) Raise the blend door actuator far enough to
access and disconnect the rear HVAC wire harness
connector from the actuator.
(10) Remove the rear blend door actuator from
between the rear HVAC housing and the quarter
inner panel.
INSTALLATION
(1) Position the blend door actuator between the
rear HVAC housing and the quarter inner panel.
(2) Connect the rear HVAC wire harness connector
to the rear blend door actuator.
(3) Position the rear blend door actuator onto the
rear HVAC housing. If necessary, rotate the actuator
slightly to align the splines on the actuator output
shaft with those in the blend air door pivot.
(4) Install the two screws that secure the rear
blend door actuator to the rear HVAC housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(5) Push the top of the rear HVAC housing back
into position against the right quarter inner panel.
Fig. 3 Rear HVAC Mode Door Actuator
1 - SCREW (2)
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - CONNECTOR
5 - BLEND DOOR ACTUATOR
6 - WIRE HARNESS CONNECTOR
RSCONTROLS - REAR24-35
BLEND DOOR ACTUATOR (Continued)