
BLOWER MOTOR RESISTOR
DESCRIPTION
A blower motor resistor is used on this model when
it is equipped with the manual heater-A/C control
(Fig. 7). Models equipped with the optional Auto-
matic Temperature Control (ATC) use a blower power
module, instead of the blower motor resistor. The
blower motor resistor is installed in a mounting hole
on the back of the rear heater-A/C unit housing,
directly above the expansion valve. The resistor con-
sists of a molded plastic mounting plate with an inte-
gral connector receptacle. Concealed behind the
mounting plate within the rear heater-A/C unit hous-
ing are two coiled resistor wires contained within a
protective stamped steel cage. The resistor mounting
plate is secured with two screws to the rear heater-
A/C unit housing and is accessed for service by
removing the right quarter and D-pillar trim panels.The blower motor resistor wires will get hot when
in use. Do not touch the resistor wires or the protec-
tive cage if the blower motor has been running. The
blower motor resistor cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The blower motor resistor is connected to the vehi-
cle electrical system through a dedicated take out
and connector of the rear HVAC wire harness. The
blower motor resistor has two resistor wires, 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 con-
trol directs the ground path for the blower motor
through the correct resistor wire to obtain the
selected speed. With the blower motor switch in the
lowest speed position, the ground path for the motor
is applied through both resistor wires. Each higher
speed selected with the blower motor switch applies
the blower motor ground path through fewer of the
resistor wires, increasing the blower motor speed.
When the blower motor switch is in the highest
speed position, the blower motor resistor wires are
bypassed and the blower motor receives a direct path
to ground through the blower motor switch. The
blower motor resistor may be diagnosed using con-
ventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RESISTOR
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the rear HVAC wire harness con-
nector for the blower motor resistor from the resistor
connector receptacle.
(3) Check for continuity between each of the
blower motor switch input terminals of the blower
motor resistor and the resistor output terminal. In
each case there should be continuity. If OK, repair
the wire harness circuits between the blower motor
switch and the blower motor resistor or the blower
motor pigtail wires as required. If not OK, replace
the faulty blower motor resistor.Fig. 7 Blower Motor Resistor
1 - REAR HEATER-A/C UNIT HOUSING
2 - D-PILLAR
3 - BLOWER PIGTAIL WIRE
4 - CONNECTOR
5 - EXPANSION VALVE
6 - SCREW (2)
7 - BLOWER MOTOR RESISTOR
RSCONTROLS - REAR24-35
ProCarManuals.com

(9) Remove the seal from the discharge line fitting
and discard.
(10) Install plugs in, or tape over the opened dis-
charge line fitting and the compressor discharge port.
(11) Raise and support the vehicle.
(12) Remove the serpentine accessory drive belt
from the front of the engine. (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - 2.4L -
REMOVAL) or (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - 3.3L/3.8L - REMOVAL).
(13) Disconnect the engine wire harness connector
for the compressor clutch coil from the coil pigtail
wire connector on the top of the compressor (Fig. 1)
or (Fig. 2).
(14) On models with the 3.3L and 3.8L engines,
disengage the retainer on the engine wire harness
compressor clutch coil take out from the bracket on
the top of the compressor.
(15) On models with the 2.4L engine, remove the
four screws that secure the compressor to the mount-
ing bracket on the engine.
(16) On models with the 3.3L and 3.8L engines,
remove the three screws and one nut that secure the
compressor to the engine.
(17) Remove the compressor from the engine com-
partment.
NOTE: If a replacement compressor is being
installed, be certain to drain and measure the refrig-
erant oil contained in the removed compressor.
This will determine how much oil the replacement
compressor must contain before it is installed.(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT/REFRIGERANT OIL - STAN-
DARD PROCEDURE - REFRIGERANT OIL LEVEL).
REMOVAL - COMPRESSOR MOUNTING
BRACKET - 2.4L ENGINE
(1) Remove the compressor from the mounting
bracket. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/COMPRESSOR - REMOVAL).
(2) Remove the four screws that secure the com-
pressor mounting bracket to the engine (Fig. 3).
(3) Remove the compressor mounting bracket from
the engine.
INSTALLATION - COMPRESSOR
NOTE: If a replacement compressor is being
installed, be certain to check the refrigerant oil
level. (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT/REFRIGERANT OIL - STAN-
DARD PROCEDURE - REFRIGERANT OIL LEVEL).
Use only refrigerant oil of the type recommended
for the compressor in the vehicle.
(1) Position the compressor into the engine com-
partment.
(2) On models with the 2.4L engine, loosely install
the four screws that secure the compressor to the
mounting bracket on the engine (Fig. 1). Tighten the
screws to 28 N´m (21 ft. lbs.).
Fig. 1 Compressor - 2.4L Engine
1 - CLUTCH COIL CONNECTOR
2 - DISCHARGE PORT
3 - COMPRESSOR
4 - SUCTION PORT
5 - SCREW (4)
6 - COMPRESSOR MOUNTING BRACKET
Fig. 2 Compressor - 3.3L/3.8L Engine
1 - STUD
2 - CLUTCH COIL CONNECTOR
3 - DISCHARGE PORT
4 - SCREW (2)
5 - SUCTION PORT
6 - COMPRESSOR
7 - SCREW
8 - NUT
24 - 66 PLUMBING - FRONTRS
COMPRESSOR (Continued)
ProCarManuals.com

INSTALLATION
NOTE: If the condenser is being replaced, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the compressor in the vehi-
cle.
NOTE: Be certain that each of the radiator and con-
denser air seals are reinstalled in their proper loca-
tions. These air seals are required in order for the
air conditioning and engine cooling systems to per-
form as designed.
(1) Position the condenser to the right mounting
bracket and transmission oil cooler unit.
(2) Position the left mounting bracket onto the side
of the condenser and transmission oil cooler.
(3) Install and tighten the one screw that secures
the left mounting bracket to the side of the transmis-
sion oil cooler. Tighten the screw to 5 N´m (45 in.
lbs.).
(4) Install and tighten the two screws that secure
each mounting bracket to the sides of the condenser.
Tighten the screws to 5 N´m (45 in. lbs.).(5) Position the condenser, transmission oil cooler,
and mounting brackets into the vehicle as a unit. Be
certain that the locating pins that secure the mount-
ing brackets are engaged in the lower mount rubber
isolators on each side of the cooling module (Fig. 5).
(6) Install and tighten the two screws that secure
the top of the mounting bracket on each side of the
condenser to the cooling module. Tighten the screws
to 5 N´m (45 in. lbs.).
(7) Remove the tape or plugs from the condenser
outlet port and the liquid line fitting.
(8) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(9) Reconnect the liquid line fitting to the con-
denser outlet port on the right side of the cooling
module.
(10) Install and tighten the nut that secures the
liquid line fitting to the condenser. Tighten the nut to
23 N´m (17 ft. lbs.).
(11) Remove the tape or plugs from the condenser
inlet port and the discharge line fitting.
(12) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(13) Reconnect the discharge line fitting to the
condenser inlet port on the right side of the cooling
module.
(14) Install and tighten the nut that secures the
discharge line fitting to the condenser. Tighten the
nut to 23 N´m (17 ft. lbs.).
(15) Reconnect the hoses to the transmission oil
cooler fittings on the left side of the cooling module.
(Refer to 7 - COOLING/TRANSMISSION/TRANS
COOLER LINES - INSTALLATION).
(16) Reposition the hood latch unit to the front of
the radiator closure panel crossmember.
(17) Install and tighten the two screws that secure
the hood latch unit to the front of the radiator clo-
sure panel crossmember. Check and adjust the hood
latch as needed. Tighten the screws to 14 N´m (123
in. lbs.).
(18) Position the radiator sight shield onto the
radiator closure panel crossmember (Fig. 4).
(19) Install and tighten the five small screws that
secure the front fascia grille inserts to the radiator
sight shield. Tighten the screws to 2 N´m (18 in. lbs.).
(20) Install and tighten the two large screws that
secure the front fascia and the outboard ends of the
radiator sight shield to the radiator closure panel
crossmember. Tighten the screws to 6 N´m (53 in.
lbs.).
(21) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
Fig. 5 Condenser Mounting
1 - SCREW (2)
2 - LOWER MOUNT ISOLATOR (2)
3 - CONDENSER
RSPLUMBING - FRONT24-69
CONDENSER (Continued)
ProCarManuals.com

ND-8 PAG refrigerant oil. Use only refrigerant oil of
this same type to service the refrigerant system.
OPERATION
After performing any refrigerant recovery or recy-
cling operation, always replenish the refrigerant sys-
tem with the same amount of the recommended
refrigerant oil as was removed. Too little refrigerant
oil can cause compressor damage, and too much can
reduce air conditioning system performance. PAG
refrigerant oil is much more hygroscopic than min-
eral oil, and will absorb any moisture it comes into
contact with, even moisture in the air. The PAG oil
container should always be kept tightly capped until
it is ready to be used. After use, recap the oil con-
tainer immediately to prevent moisture contamina-
tion.
STANDARD PROCEDURE - REFRIGERANT OIL
LEVEL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).
When an air conditioning system is assembled at
the factory, all components except the compressor are
refrigerant oil free. After the refrigerant system has
been charged and operated, the refrigerant oil in the
compressor is dispersed throughout the refrigerant
system. The receiver/drier, evaporator, condenser, and
compressor will each retain a significant amount of
the needed refrigerant oil.
It is important to have the correct amount of oil in
the refrigerant system. This ensures proper lubrica-
tion of the compressor. Too little oil will result in
damage to the compressor. Too much oil will reduce
the cooling capacity of the air conditioning system.
It will not be necessary to check the oil level in the
compressor or to add oil, unless there has been an oil
loss. An oil loss may occur due to a rupture or leak
from a refrigerant line, a connector fitting, a compo-
nent, or a component seal. If a leak occurs, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system after the repair has been made.
Refrigerant oil loss will be evident at the leak point
by the presence of a wet, shiny surface around the
leak.
Refrigerant oil must be added when an receiver/
drier, evaporator or condenser is replaced. See the
Refrigerant Oil Capacities chart for the proper
amount of refrigerant oil to add. When a compressoris replaced, the refrigerant oil must be drained from
the old compressor and measured. Drain all of the
refrigerant oil from the new compressor, then fill the
new compressor with the same amount of fresh new
refrigerant oil that was drained out of the old com-
pressor.
REFRIGERANT OIL CAPACITIES
Front A/C Front & Rear
A/C
COMPONENT ml fl oz ml fl oz
Compressor 150 5.0 220 7.4
Filter-Drier 30 1.0 30 1.0
Condenser 30 1.0 30 1.0
Front Evaporator 60 2.0 60 2.0
Rear Evap. (including
underbody lines)N/A N/A 60 2.0
Compressor Drain and measure the oil
from the old compressor -
See text above.
SUCTION LINE
REMOVAL
The front air conditioner suction line includes the
low side service port on a section of tubing located
near the compressor. On models equipped with the
optional rear air conditioner, the front air conditioner
suction line also includes a suction line hose and
tube extension that connects the front suction line to
the suction line for the rear air conditioner.
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).
(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/REFRIGERANT -
STANDARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the air cleaner top cover and snorkel
from the air cleaner housing located on the right side
of the engine compartment.
(4) Disconnect the drain tube from the wiper mod-
ule drain on the right side of the engine compart-
ment.
24 - 92 PLUMBING - FRONTRS
REFRIGERANT OIL (Continued)
ProCarManuals.com

(4) Raise the liquid line (discharge) pressure to
about 1793 kPa (260 psi) by placing a piece of card-
board over part of the front side of the condenser. To
place the cardboard properly, remove the upper radi-
ator sight shield from the front fascia. Cover only
enough of the condenser to raise and maintain the
liquid line pressure at the specified level.
(5) Observe the liquid line (discharge) pressure
and liquid line temperature. Using the Charge Deter-
mination Chart (Fig. 3), determine whether the
refrigerant system is operating within the Proper
Charge Range.
(a) If the refrigerant system is operating in the
Undercharged area of the chart, add 0.057 kilo-
gram (0.125 pound or 2 ounces) of refrigerant to
the system.
(b) If the refrigerant system is operating in the
Overcharged area of the chart, reclaim 0.057 kilo-
gram (0.125 pound or 2 ounces) of refrigerant from
the system.
(6) Recheck the system charge level following each
refrigerant adjustment. Continue this process until
the system readings are in the Proper Charge Range
area on the Charge Determination Chart (Fig. 3).DIESEL SUPPLEMENTAL
HEATER - DCHA
DESCRIPTION
Vehicles equipped with the optional diesel engine are
also equipped with a supplemental heater unit. This
unit is mounted under the vehicle and operates similar
to an oil fired furnace. The heater burns small
amounts of fuel to provide additional heat to the cool-
ant. Coolant is routed from the engine, to the supple-
mental heater, and then to the front heater core. This
provides additional heat to the passenger compart-
ment. The system is interfaced to the vehicles on-board
computer systems and DRB-III diagnostics.
Fig. 3 Charge Determination Chart, Ambient Test Condition 85ÉF
RGHEATING & AIR CONDITIONING24a-5
REFRIGERANT (Continued)
ProCarManuals.com

put component, it can verify that the command was
carried out by monitoring specific input signals for
expected changes. For example, when the PCM com-
mands the Idle Air Control (IAC) Motor to a specific
position under certain operating conditions, it expects
to see a specific (target) idle speed (RPM). If it does
not, it stores a DTC.
PCM outputs monitored for functionality include:
²Fuel Injectors
²Ignition Coils
²Torque Converter Clutch Solenoid
²Idle Air Control
²Purge Solenoid
²EGR Solenoid
²LDP Solenoid
²Radiator Fan Control
²Trans Controls
OXYGEN SENSOR (O2S) MONITOR
DESCRIPTIONÐEffective control of exhaust
emissions is achieved by an oxygen feedback system.
The most important element of the feedback system
is the O2S. The O2S is located in the exhaust path.
Once it reaches operating temperature 300É to 350ÉC
(572É to 662ÉF), the sensor generates a voltage that
is inversely proportional to the amount of oxygen in
the exhaust. When there is a large amount of oxygen
in the exhaust caused by a lean condition, the sensor
produces a low voltage, below 450 mV. When the oxy-
gen content is lower, caused by a rich condition, the
sensor produces a higher voltage, above 450mV.
The information obtained by the sensor is used to
calculate the fuel injector pulse width. The PCM is
programmed to maintain the optimum air/fuel ratio.
At this mixture ratio, the catalyst works best to
remove hydrocarbons (HC), carbon monoxide (CO)
and nitrous oxide (NOx) from the exhaust.
The O2S is also the main sensing element for the
EGR, Catalyst and Fuel Monitors.
The O2S may fail in any or all of the following
manners:
²Slow response rate (Big Slope)
²Reduced output voltage (Half Cycle)
²Heater Performance
Slow Response Rate (Big Slope)ÐResponse rate
is the time required for the sensor to switch from
lean to rich signal output once it is exposed to a
richer than optimum A/F mixture or vice versa. As
the PCM adjusts the air/fuel ratio, the sensor must
be able to rapidly detect the change. As the sensor
ages, it could take longer to detect the changes in the
oxygen content of the exhaust gas. The rate of
change that an oxygen sensor experiences is called
'Big Slope'. The PCM checks the oxygen sensor volt-
age in increments of a few milliseconds.Reduced Output Voltage (Half Cycle)ÐThe
output voltage of the O2S ranges from 0 to 1 volt. A
good sensor can easily generate any output voltage in
this range as it is exposed to different concentrations
of oxygen. To detect a shift in the A/F mixture (lean
or rich), the output voltage has to change beyond a
threshold value. A malfunctioning sensor could have
difficulty changing beyond the threshold value. Each
time the voltage signal surpasses the threshold, a
counter is incremented by one. This is called the Half
Cycle Counter.
Heater PerformanceÐThe heater is tested by a
separate monitor. Refer to the Oxygen Sensor Heater
Monitor.
OPERATIONÐAs the Oxygen Sensor signal
switches, the PCM monitors the half cycle and big
slope signals from the oxygen sensor. If during the
test neither counter reaches a predetermined value, a
malfunction is entered and a Freeze Frame is stored.
Only one counter reaching its predetermined value is
needed for the monitor to pass.
The Oxygen Sensor Monitor is a two trip monitor
that is tested only once per trip. When the Oxygen
Sensor fails the test in two consecutive trips, the
MIL is illuminated and a DTC is set. The MIL is
extinguished when the Oxygen Sensor monitor
passes in three consecutive trips. The DTC is erased
from memory after 40 consecutive warm-up cycles
without test failure.
Enabling ConditionsÐThe following conditions
must typically be met for the PCM to run the oxygen
sensor monitor:
²Battery voltage
²Engine temperature
²Engine run time
²Engine run time at a predetermined speed
²Engine run time at a predetermined speed and
throttle opening
²Transmission in gear (automatic only)
²Fuel system in Closed Loop
²Long Term Adaptive (within parameters)
²Power Steering Switch in low PSI (no load)
²Engine at idle
²Fuel level above 15%
²Ambient air temperature
²Barometric pressure
²Engine RPM within acceptable range of desired
idle
²Closed throttle speed
Pending ConditionsÐThe Task Manager typi-
cally does not run the Oxygen Sensor Monitor if over-
lapping monitors are running or the MIL is
illuminated for any of the following:
²Misfire Monitor
²Front Oxygen Sensor and Heater Monitor
²MAP Sensor
25 - 2 EMISSIONS CONTROLRS
EMISSIONS CONTROL (Continued)
ProCarManuals.com