Chrysler RG Voyager. Manual - part 1214

mance and to protect the system components from
damage. The PCM will disengage the A/C compressor
clutch when high side pressure rises above 3082 kPa
(447 psi) and re-engage the clutch when high side
pressure drops below 2937 kPa (426 psi). The A/C
pressure transducer will also disengage the A/C com-
pressor clutch if the high side pressure drops below
110 kPa (16 psi) and will re-engage the clutch when
the high side pressure rises above 221 kPa (32 psi).
If the refrigerant pressure rises above 1655 kPa (240
psi), the PCM will actuate the cooling fan. The A/C
pressure transducer input to the PCM will also pre-
vent the A/C compressor clutch from engaging when
ambient temperatures are below about 4.5° C (40° F)
due to the pressure/temperature relationship of the
refrigerant.

The A/C pressure transducer is diagnosed using a

DRBIII

t scan tool. Refer to 9 - Engine Electrical

Diagnostics for more information.

The A/C pressure transducer cannot be adjusted or

repaired and, if faulty or damaged, it must be
replaced.

DIAGNOSIS AND TESTING

A/C PRESSURE TRANSDUCER

The A/C pressure transducer is tested using a

DRBIII

t scan tool. Refer to the appropriate diagnos-

tic information. Before testing the A/C pressure
transducer, be certain that the transducer wire har-
ness connection is clean of corrosion and properly
connected. For the A/C to operate, an A/C pressure
transducer voltage reading between 0.451 and 4.519
volts is required. Voltages outside this range indicate

a low or high refrigerant system pressure condition
to the powertrain control module (PCM). The PCM is
programmed to respond to a low or high refrigerant
system pressure by suppressing operation of the A/C
compressor. Refer to the A/C Pressure Transducer
Voltage chart for the possible conditions indicated by
the transducer voltage reading.

A/C PRESSURE TRANSDUCER VOLTAGE

Voltage

Possible Indication

0.0

1. No sensor supply voltage from
PCM.

2. Shorted sensor circuit.

3. Faulty transducer.

0.150 TO 0.450

1. Ambient temperature below
10° C (50° F).

2. Low refrigerant system
pressure.

0.451 TO 4.519

1. Normal refrigerant system
pressure.

4.520 TO 4.850

1. High refrigerant system
pressure.

5.0

1. Open sensor circuit.

2. Faulty transducer.

REMOVAL

NOTE: It is not necessary to discharge the refriger-
ant system to replace the A/C pressure transducer.

(1) Disconnect and isolate the negative battery

cable.

(2) Disconnect the wire harness connector from the

A/C pressure transducer located on the liquid line
(Fig. 12).

(3) Remove the A/C pressure transducer from the

fitting on the liquid line and remove and discard the
O-ring seal.

INSTALLATION

NOTE: Use only the specified O-ring as it is made
of special material for R-134a. Use only refrigerant
oil of the type required for the A/C compressor.

(1) Lubricate a new rubber O-ring seal with clean

refrigerant oil and install it on the liquid line fitting.

(2) Install the A/C pressure transducer onto the

liquid line. Tighten the A/C pressure transducer
securely.

Fig. 11 A/C Pressure Transducer

1 - A/C PRESSURE TRANSDUCER

CONTROLS - FRONT

24 - 21

A/C PRESSURE TRANSDUCER (Continued)

(3) Connect the wire harness connector to the A/C

pressure transducer.

(4) Reconnect the negative battery cable.

BLEND DOOR ACTUATOR

DESCRIPTION

The blend door actuators for the front heating-A/C

system are reversible, 12-volt Direct Current (DC),
servo motors (Fig. 13). Models with the front single
zone heating-A/C system have a single blend-air door,
which is controlled by a single blend door actuator.
Models with the optional front dual zone heating-A/C
system have dual blend-air doors, which are con-
trolled by two blend door actuators.

The blend door actuator for the single zone heat-

ing-A/C system is located on the driver side end of
the front HVAC air distribution housing, close to the
middle of the distribution housing.

For the dual zone heating-A/C system, the same

blend door actuator used for the single zone system
becomes the driver side blend door actuator, which is
mechanically connected to only the driver side blend-
air door. A second separate blend door actuator is
also located on the driver side of the front HVAC air
distribution housing which is mechanically connected
to only the passenger side blend-air door.

The front blend door actuators are interchangeable

with each other, as well as with the actuators for the
mode-air door and the recirculation-air door. Each
actuator is contained within an identical black
molded plastic housing with an integral wire connec-
tor receptacle. Each actuator also has an identical

output shaft with splines that connects it to its
respective door linkage and two integral mounting
tabs that allow the actuator to be secured to the
front HVAC housing. The front blend door actuators
do not require mechanical indexing to the blend-air
doors, as they are electronically calibrated by the
A/C-heater control.

The A/C-heater control must be recalibrated each

time an actuator motor is replaced (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS -
FRONT/A/C

HEATER

CONTROL

STANDARD

PROCEDURE -A/C-HEATER CONTROL CALIBRA-
TION).

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 posi-

tioning system 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-

Fig. 12 A/C Pressure Transducer - Typical

1 - RIGHT FRONT STRUT TOWER
2 - WIRE HARNESS CONNECTOR
3 - A/C PRESSURE TRANSDUCER
4 - WIPER MODULE DRAIN TUBE
5 - HIGH SIDE SERVICE PORT
6 - LIQUID LINE

Fig. 13 Blend Door Actuator

1 - ACTUATOR MOTOR
2 - WIRE CONNECTOR RECEPTACLE
3 - OUTPUT SHAFT
4 - MOUNTING TAB (2)

24 - 22

CONTROLS - FRONT

A/C PRESSURE TRANSDUCER (Continued)

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 blend door actuators are diagnosed using a

DRBIII

t scan tool. Refer to 9 - Engine 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 airbags, dis-
able the airbag system before attempting any steer-
ing wheel, steering column, or instrument panel
component diagnosis or service. Disconnect and
isolate the negative battery (ground) cable, then
wait two minutes for the airbag system capacitor to
discharge before performing further diagnosis or
service. This is the only sure way to disable the air-
bag system. Failure to take the proper precautions
could result in accidental airbag deployment and
possible personal injury or death.

NOTE:

The

single

zone

heater-A/C

system

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.

(1) Disconnect and isolate the negative battery

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 being serviced (Fig. 14).

(4) Remove the two screws that secure the blend

door actuator being serviced to the HVAC air distri-
bution housing and remove the actuator.

INSTALLATION

(1) Position the blend door actuator being serviced

onto the air distribution 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 being serviced to the air distribution
housing. Tighten the screws to 2 N·m (17 in. lbs.).

(3) Connect the HVAC wire harness connector to

the blend door actuator being serviced.

(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 and cali-

brate the A/C-heater control (Refer to 24 - HEATING
& AIR CONDITIONING/CONTROLS - FRONT/A/C
HEATER CONTROL - STANDARD PROCEDURE
-A/C-HEATER CONTROL CALIBRATION).

BLOWER MOTOR POWER
MODULE

DESCRIPTION

A front blower motor power module is used on this

model when it is equipped with the automatic tem-
perature control (ATC) heating-A/C system (Fig. 15).
Models equipped with the manual temperature con-
trol (MTC) heating-A/C system use a blower motor
resistor, instead of the blower motor power module
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS-FRONT/RESISTOR-BLOWER MOTOR -
DESCRIPTION).

The front blower motor power module is mounted

to the rear of the front HVAC housing, directly
behind the glove box. The blower motor power mod-
ule consists of a molded plastic mounting plate with
two integral connector receptacles (1). Concealed
behind the mounting plate is the power module elec-
tronic circuitry and a large finned heat sink (2). The
front blower motor power module is accessed for ser-
vice by removing the glove box.

Fig. 14 Blend Door Actuator

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)

CONTROLS - FRONT

24 - 23

BLEND DOOR ACTUATOR (Continued)

OPERATION

The front blower motor power module is connected

to the vehicle electrical system through a dedicated
lead and connector of the front HVAC wire harness.
A second connector receptacle receives the wire har-
ness connector from the front blower motor. The front
blower motor power module allows the microproces-
sor-based automatic temperature control (ATC) A/C-
heater control 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
front blower motor feedback voltage. The resulting
output drives the power module circuitry, which pro-
vides a linear output voltage to change or maintain
the desired blower speed.

The front blower motor power module is diagnosed

using a DRBIII

t scan tool. Refer to Body Diagnostic

Procedures.

The front blower motor power module cannot be

adjusted or repaired and, if faulty or damaged, it
must be replaced.

REMOVAL

discharge before performing further diagnosis or
service. This is the only sure way to disable the air-
bag system. Failure to take the proper precautions
could result in accidental airbag deployment and
possible personal injury or death.

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 service. Failure to take this
precaution can result in possible personal injury.

(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 front blower motor power module (Fig. 16).

(4) Remove the two screws that secure the front

blower motor power module to the front HVAC hous-
ing and remove the power module.

INSTALLATION

(1) Position the front blower motor power module

into the front HVAC housing.

(2) Install the two screws that secure the front

blower motor power module to the front HVAC hous-
ing. Tighten the screws to 2 N·m (17 in. lbs.).

(3) Connect the two wire connectors to the front

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.

Fig. 15 Front Blower Motor Power Module

1 - BLOWER MOTOR POWER MODULE
2 - HEAT SINK

Fig. 16 Front Blower Motor Power Module

1 - FRONT BLOWER MOTOR POWER MODULE
2 - LOWER GLOVE BOX OPENING REINFORCEMENT
3 - FRONT HVAC HOUSING

24 - 24

CONTROLS - FRONT

BLOWER MOTOR POWER MODULE (Continued)

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