CLEANING
Drain cooling system and refill with clean water.
Refer to drain and fill procedures in this section. Run
engine with radiator cap installed until upper radia-
tor hose is hot. Stop engine and drain water from
system. If water is dirty; fill, run, and drain system
again, until water runs clear. Refill cooling system
with a 50/50 mixture of the recommended ethylene
glycol and distilled water (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES - DESCRIPTION).
INSPECTION
After performing a cleaning/flush procedure,
inspect all hoses, clamps and connections for deterio-
ration and leaks. Inspect radiator and heater core for
leaks.
Fig. 1 Temperature Gauge Indications
7 - 18 ENGINERS
ENGINE (Continued)
COOLANT RECOVERY
CONTAINER
DESCRIPTION
The coolant recovery/reserve system container is
mounted in the engine compartment (Fig. 2). The
container is made of plastic.
OPERATION
The coolant recovery system works with the radia-
tor pressure cap to use thermal expansion and con-
traction of the coolant to keep the coolant free of
trapped air. Provides a convenient and safe method
for checking coolant level and adjusting level at
atmospheric pressure without removing the radiator
pressure cap. It also provides reserve coolant to cover
deaeration, evaporation, or boiling losses.
DIAGNOSIS AND TESTING - COOLANT
RECOVERY SYSTEM
The cooling system is closed and designed to main-
tain coolant level to the top of the radiator.
(1) With the engineoffand cooling systemnot
under pressure, drain several ounces of coolant from
the radiator draincock while observing the coolant
recovery container. Coolant level in the container
should drop.
(2) Remove the radiator pressure cap. The coolant
level should be full to the top radiator neck. If not,
and the coolant level in the container is at or above
the MIN mark, there is an air leak in the coolant
recovery system.
(3) Check hose and hose connections to the con-
tainer, radiator filler neck or the pressure cap seal to
the radiator filler neck for leaks.
REMOVAL
(1) Raise the vehicle on hoist.
(2) Remove the lower attaching screws (Fig. 2).
(3) Lower the vehicle.
(4) Remove the upper attaching screw (Fig. 2).
(5) Disconnect recovery hose from container (Fig.
2).
(6) Remove the recovery container.
INSTALLATION
(1) Connect the recovery hose to container (Fig. 2).
(2) Position the recovery container on the frame
rail (Fig. 2).
(3) Install the upper attaching screw and tighten
to 7 N´m (60 in. lbs.) (Fig. 2).
(4) Raise the vehicle on hoist.
(5) Install the lower attaching screws and tighten
to 8.5 N´m (75 in. lbs.) (Fig. 2).
(6) Lower the vehicle.(7) Add coolant to container as necessary. (Refer to
7 - COOLING - STANDARD PROCEDURE)
ENGINE BLOCK HEATER
DESCRIPTION
The engine block heater is available as an optional
accessory on all models. The heater is operated by
ordinary house current (110 Volt A.C.) through a
power cord located behind the radiator grille. This
provides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures. The heater is mounted in a core
hole (in place of a core hole plug) in the engine block,
with the heating element immersed in coolant.
OPERATION
The block heater element is submerged in the cool-
ing system's coolant. When electrical power (110 volt
A.C.) is applied to the element, it creates heat. This
heat is transferred to the engine coolant. This pro-
vides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures.
Fig. 2 Coolant Recovery Container
1 - COOLANT RECOVERY CONTAINER
2 - HOSE
3 - BOLT
4 - SUB FRAME RAIL
7 - 20 ENGINERS
INSTALLATION
(1)Be sure the air seal is in position before
radiator is installed.Slide radiator down into posi-
tion. Seat the radiator with the rubber isolators into
the mounting holes provided, with a 10 lbs. force.
(2) Position air conditioning condenser onto the
radiator lower mounts and ingage upper mounting
tabs. (Fig. 15).
(3) Install the radiator upper and lower hoses (Fig.
13) or (Fig. 14).
(4) Connect the coolant reserve/recovery hose.
(5) Connect the vapor purge solenoid to the mount-
ing bracket.
(6) Install the radiator fans. (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - INSTALLATION)
(7) Install the radiator upper crossmember sup-
port. (Refer to 23 - BODY/EXTERIOR/GRILLE
OPENING REINFORCEMENT - INSTALLATION)
(8) Fill the cooling system. (Refer to 7 - COOLING
- STANDARD PROCEDURE)
(9) Connect negative cable to battery.
RADIATOR DRAINCOCK
REMOVAL
NOTE: It is not necessary to remove draincock dur-
ing a routine coolant drain.
(1) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(2) Using a screwdriver, open the draincock by
turning it counterclockwise until it stops.
(3) Pull the draincock from the radiator tank.
INSTALLATION
(1) Align draincock stem to radiator tank opening.
(2) Push draincock into the radiator tank opening.
CAUTION: Do not overtighten. The head of the
draincock may break off.
(3) Using a screwdriver, tighten the draincock by
turning clockwise until it stops.
(4) Fill the cooling system. (Refer to 7 - COOLING
- STANDARD PROCEDURE)
RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system pressure cap is located on the
radiator. The cap construction includes; stainless
steel swivel top, rubber seals, and retainer, main
spring, and a spring loaded valve (Fig. 16).
OPERATION
The cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a range
of 97-124 kPa (14-18 psi).
The cooling system will operate at higher than
atmospheric pressure. The higher pressure raises the
coolant boiling point thus, allowing increased radia-
tor cooling capacity.
There is also a vent valve in the center of the cap.
This valve also opens when coolant is cooling and
contracting, allowing the coolant to return to cooling
system from coolant reserve system tank by vacuum
through a connecting hose.If valve is stuck shut,
or the coolant recovery hose is pinched, the
radiator hoses will be collapsed on cool down.
Clean the vent valve (Fig. 16) and inspect cool-
ant recovery hose routing, to ensure proper
sealing when boiling point is reached.
The gasket in the cap seals the filler neck, so that
vacuum can be maintained, allowing coolant to be
drawn back into the radiator from the reserve tank.
If the gasket is dirty or damaged, a vacuum
may not be achieved, resulting is loss of coolant
and eventual overheating due to low coolant
level in radiator and engine.
Fig. 16 Cooling System Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
RSENGINE7-27
RADIATOR (Continued)
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEM
PRESSURE CAP TESTING
Dip the pressure cap in water. Clean any deposits
off the vent valve or its seat and apply cap to end of
the Pressure Cap Test Adaptor that is included with
the Cooling System Tester 7700 (Fig. 17). Working
the plunger, bring the pressure to 104 kPa (15 psi) on
the gauge. If the pressure cap fails to hold pressure
of at least 97 kPa (14 psi), replace the pressure cap.
CAUTION: The Cooling System Tester Tool is very
sensitive to small air leaks that will not cause cool-
ing system problems. A pressure cap that does not
have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to the tool. Turn tool
upside down and recheck pressure cap to confirm
that cap is bad.
If the pressure cap tests properly while positioned
on Cooling System Tester (Fig. 17), but will not hold
pressure or vacuum when positioned on the filler
neck. Inspect the filler neck and cap top gasket for
irregularities that may prevent the cap from sealing
properly.
DIAGNOSIS AND TESTING - RADIATOR CAP
TO FILLER NECK SEAL
The pressure cap upper gasket (seal) pressure
relief can be checked by removing the overflow hose
at the radiator filler neck nipple (Fig. 18). Attach the
Radiator Pressure Tool to the filler neck nipple and
pump air into the radiator. Pressure cap upper gas-
ket should relieve at 69-124 kPa (10-18 psi) and hold
pressure at 55 kPa (8 psi) minimum.WARNING: THE WARNING WORDS ªDO NOT OPEN
HOTº ON THE RADIATOR PRESSURE CAP IS A
SAFETY PRECAUTION. WHEN HOT, PRESSURE
BUILDS UP IN COOLING SYSTEM. TO PREVENT
SCALDING OR INJURY, THE RADIATOR CAP
SHOULD NOT BE REMOVED WHILE THE SYSTEM
IS HOT OR UNDER PRESSURE.
There is no need to remove the radiator cap at any
timeexceptfor the following purposes:
(1) Check and adjust coolant freeze point.
(2) Refill system with new coolant.
(3) Conducting service procedures.
(4) Checking for vacuum leaks.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY,
WAIT 15 MINUTES BEFORE REMOVING CAP. THEN
PLACE A SHOP TOWEL OVER THE CAP AND WITH-
OUT PUSHING DOWN ROTATE COUNTERCLOCK-
WISE TO THE FIRST STOP. ALLOW FLUIDS TO
ESCAPE THROUGH THE OVERFLOW TUBE AND
WHEN THE SYSTEM STOPS PUSHING COOLANT
AND STEAM INTO THE CRS TANK AND PRESSURE
DROPS PUSH DOWN AND REMOVE THE CAP COM-
PLETELY. SQUEEZING THE RADIATOR INLET HOSE
WITH A SHOP TOWEL (TO CHECK PRESSURE)
BEFORE AND AFTER TURNING TO THE FIRST
STOP IS RECOMMENDED.
CLEANING
Use only a mild soap to clean the pressure cap.
Fig. 17 Testing Cooling System Pressure Cap
1 - PRESSURE CAP
2 - PRESSURE TESTER
Fig. 18 Radiator Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
7 - 28 ENGINERS
RADIATOR PRESSURE CAP (Continued)
INSPECTION
Hold the cap in your hand,top side up(Fig. 19).
The vent valve at the bottom of the cap should open.
If the rubber gasket has swollen, preventing the
valve from opening, replace the cap.
Hold the cleaned cap in your hand,upside down.
If any light can be seen between vent valve and the
rubber gasket, replace the cap.Do not use a
replacement cap that has a spring to hold the
vent shut.
A replacement cap must be of the type designed for
coolant reserve systems. This design ensures coolant
return to the radiator.
RADIATOR FAN
DESCRIPTION
The dual radiator fans are mounted to the back
side of the radiator (Fig. 20). The radiator fan consist
of the fan blade, electric motor and a support shroud
which are all serviced as an assembly.
OPERATION
RADIATOR FAN OPERATION CHART
COOLANT TEMPERATURE A/C PRESSURE TRANSAXLE OIL
TEMPERATURE
Fan
Operation
Speeds:Initial Max Initial Max Initial Max
Fan On: 104ÉC
(220ÉF)110ÉC
(230ÉF) Fan
Speed
Duty-Cycles
(Ramps-up)
from 30% to
99%1,724 Kpa
(250 psi)2,068 Kpa
(300 psi) Fan
Speed
Duty-Cycles
(Ramps-up)
from 30% to
99%96ÉC (204ÉF) 111ÉC (232ÉF)
Fan Speed
Duty Cycles
(Ramps-up)
from 30% to
99%
Fan Off: 101ÉC
(214ÉF)Fan Speed
Duty-Cycles
(Ramps-
down) from
99% to 30%1,710 Kpa
(248 psi)Fan Speed
Duty-Cycles
(Ramps-
down) from
99% to 30%89ÉC (192ÉF) Fan Speed
Duty Cycles
(Ramps-down)
from 99% to
30%
Fig. 19 Cooling System Pressure Cap
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
RSENGINE7-29
RADIATOR PRESSURE CAP (Continued)
TRANSMISSION OIL COOLER
DESCRIPTION
The automatic transmission cooler is located in the
front of the radiator and behind the front fascia and
is conbined with the A/C condensor. The transmission
cooler is a heat exchanger that allows heat in the
transmission flud to be transferred to the air passing
over the cooler fins.
The Transmission oil cooler/A/C condenser assem-
blly is equipped with quick connect fitting for the
transmission oil cooler lines, a tapping block, for the
receiver/drier, and mounting provisions for the power
steering cooler.
The transmission oil cooler/AC condenser is ser-
viced as an assembly. For removal on vehicles
equipped with 2.4L/3.3L/3.8L engines, (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
CONDENSER - REMOVAL), vehicles equipped with2.5L/2.8L engines (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING/A/C CONDENSER -
REMOVAL). For installation on vehicles equipped
with 2.4L/3.3L/3.8L engines (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/A/C CON-
DENSER - INSTALLATION), and vehicles equipped
with 2.5L/2.8L engines (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING/A/C CON-
DENSER - INSTALLATION).
INSPECTION
Inspect all hoses, tubes, clamps and connections for
leaks, cracks, or damage. Replace as necessary. Use
only approved transmission oil cooler hoses that are
molded to fit the space available.
Inspect external coolers for leaks, loose mounts, or
damage. Replace as necessary.
TRANSMISSION OIL COOLER
LINES
REMOVAL
(1) Remove the two large screws that secure the
front fascia and the outboard ends of the radiator
sight shield to the radiator closure panel crossmem-
ber (Fig. 3).
(2) Remove the five small screws that secure the
front fascia grille inserts to the radiator sight shield.
(3) Remove the radiator sight shield from the radi-
ator closure panel crossmember.
Fig. 2 Oil Cooler Line Quick Connect Fitting -
Assembly
1 - QUICK CONNECT FITTING
2 - CLIP
3 - OIL COOLER LINE
4 - DUST CAP
Fig. 3 Radiator Sight Shield - Typical
1 - LARGE SCREWS (2)
2 - SMALL SCREWS (5)
3 - RADIATOR SIGHT SHIELD
4 - GRILLE INSERTS
5 - FRONT FASCIA
RSTRANSMISSION7-39
TRANSMISSION (Continued)
(3) Hoist vehicle.
(4) Disconnect electrical connector (Fig. 24).
(5) Remove the two screws attaching front impact
sensor to outer rails (Fig. 24).
(6) Remove sensor from vehicle.
SIDE IMPACT SENSORS
B-PILLAR MOUNTED
The right and left front row side impact sensors,
are mounted identically, on opposite sides of the vehi-
cle, in the b-pillar.
(1) Open hood, disconnect and isolate the battery
negative cable.
(2)
WARNING: Wait two minutes for the system reserve
capacitor to discharge before beginning any airbag
component service. Personal injury or death may
result.
(3) Remove the B-pillar lower trim for the side of
the vehicle that you are replacing the side impact
sensor (Refer to 23 - BODY/INTERIOR/B-PILLAR
LOWER TRIM - REMOVAL).
(4) Disconnect the electrical connector from the
impact sensor (Fig. 25).
(5) Remove the four retaining screws to the impact
sensor bracket (Fig. 25).
(6) Remove impact sensor from vehicle (Fig. 26).
SLIDING DOOR OPENING MOUNTED
The right and left second row side impact sensors,
are mounted identically, on opposite sides of the vehi-cle, in the sliding door opening lower rear where the
lower roller arm mounts in the lower door track.
(1) Open hood, disconnect and isolate the battery
negative cable.
(2)
Fig. 24 FRONT IMPACT SENSOR REMOVE/INSTALL
1 - FRONT IMPACT SENSOR WIRE HARNESS RETAINER
2 - FRONT IMPACT SENSOR RETAINING SCREW
3 - FRONT IMPACT SENSOR WIRE HARNESS
4 - FRONT IMPACT SENSOR
5 - LOWER RADIATOR SUPPORT
Fig. 25 FRONT ROW SIDE IMPACT SENSOR AND
BRACKET
1 - B-PILLAR
2 - FRONT ROW SIDE IMPACT SENSOR ELECTRICAL
CONNECTOR
3 - FRONT ROW SIDE IMPACT SENSOR AND MOUNTING
BRACKET
4 - FRONT ROW SIDE IMPACT SENSOR RETAINING SCREW
Fig. 26 FRONT ROW SIDE IMPACT SENSOR/
BRACKET
1 - FRONT ROW SIDE IMPACT SENSOR
2 - SENSOR TO BRACKET ATTACHMENT
3 - FRONT ROW SIDE IMPACT SENSOR MOUNTING BRACKET
8O - 20 RESTRAINTSRS
IMPACT SENSOR (Continued)
restraint system protection in case there is a loss of
battery current supply to the ORC during an impact.
Two sensors are contained within the ORC, an
electronic impact sensor and a safing sensor. The
ORC also monitors inputs from eight remote impact
sensors. Two front impact sensors are located on each
outboard side of the lower radiator support, and
three side impact sensors are located on each side of
the vehicle at the B-pillar, in the lower sliding door
opening in front of the C-pillar, and over the rear
wheel well between the C and D-pillars. The elec-
tronic impact sensors are accelerometers that sense
the rate of vehicle deceleration, which provides veri-
fication of the direction and severity of an impact.
The safing sensor is an electronic accelerometer
sensor within the ORC that provides an additional
logic input to the ORC microprocessor. The safing
sensor is used to verify the need for a supplemental
restraint deployment by detecting impact energy of a
lesser magnitude than that of the primary electronic
impact sensors, and must exceed a safing threshold
in order for the airbags to deploy. Vehicles equipped
with curtain airbags, there is a second safing sensor
within the ORC to provide confirmation to the ORC
microprocessor of side impact forces. This second saf-
ing sensor is a bi-directional unit that detects impact
forces from either side of the vehicle.
Pre-programmed decision algorithms in the ORC
microprocessor determine when the deceleration rate
as signaled by the impact sensors and the safing sen-
sors indicate an impact that is severe enough to
require supplemental restraint system protection
and, based upon the severity of the monitored
impact, determines the level of front airbag deploy-
ment force required for each front seating position.
When the programmed conditions are met, the ORC
sends the proper electrical signals to deploy the dual
multistage front airbags at the programmed force
levels, the front seat belt tensioners and, if the vehi-
cle is so equipped, either curtain airbag. For vehicles
equipped with the OCS, the passenger front airbag
and seat belt tensioner will be deployed by the ORC
only if enabled by the OCM messages (PAD indicator
OFF) at the time of the impact.
To diagnose and test the ORC and all airbag sys-
tem components, use a scan tool and the appropriate
diagnostic information.
REMOVAL
WARNING: Never replace both the Occupant
Restraint Controller (ORC) and the Occupant Clas-
sification Module (OCM) at the same time. If both
require replacement, replace one, then perform the
Airbag System test (Refer to 8 - ELECTRICAL/RE-
STRAINTS - DIAGNOSIS AND TESTING - AIRBAGSYSTEM) before replacing the other. Both the ORC
and the OCM store Occupant Classification System
(OCS) calibration data, which they transfer to one
another when one of them is replaced. If both are
replaced at the same time, an irreversible fault will
be set in both modules and the OCS may malfunc-
tion and result in personal injury or death.
(1) Disconnect and isolate the battery negative
cable.
(2)
WARNING: Wait two minutes for the airbag system
reserve capacitor to discharge before beginning
any airbag system or component service. Failure to
do so may result in accidental airbag deployment,
personal injury or death.
(3) Remove storage bin from instrument panel
(Refer to 23 - BODY/INSTRUMENT PANEL/STOR-
AGE BIN - REMOVAL).
(4) Remove three bolts holding ORC to floor
bracket (Fig. 39).
(5) Disconnect the wire connectors from the ORC
(Fig. 39).
(6) Remove the ORC from vehicle.
INSTALLATION
WARNING: Do not install ORC if mounting location
is deformed or damaged. This will cause the ORC
to be improperly located and could result in occu-
pant personal injury or death.
WARNING: Use correct screws when installing the
ORC.
Fig. 39 ORC - REMOVE/INSTALL
1 - ORC ELECTRICAL CONNECTORS
2 - ORC
3 - ORC MOUNTING SCREWS
RSRESTRAINTS8O-29
OCCUPANT RESTRAINT CONTROLLER (Continued)