coolant temperature CHRYSLER VOYAGER 1996 Service Manual
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Page 1417 of 1938

±cycle, the lower the advance. The lower the duty-
±cycle, the more advanced the fuel timing.
The duty±cycle is determined by the PCM from
inputs it receives from the fuel injector sensor and
engine speed sensor.
TACHOMETERÐPCM OUTPUT
The PCM supplies engine rpm values to the Body
Controller that then supplies the instrument cluster
mounted tachometer (if equipped). Refer to Group 8E
for tachometer information.
GLOW PLUG RELAYÐPCM OUTPUT
The glow plug relay is located in the engine com-
partment on the left±inner fender (Fig. 11).
When the ignition (key) switch is placed in the ON
position, a signal is sent to the PCM relating current
engine coolant temperature. This signal is sent from
the engine coolant temperature sensor.
After receiving this signal, the PCM will determine
if, when and for how long a period the glow plug
relay should be activated. This is done before, during
and after the engine is started. Whenever the glow
plug relay is activated, it will control the 12V+ 100
amp circuit for the operation of the four glow plugs.
The Glow Plug lamp is tied to this circuit. Lamp
operation is also controlled by the PCM.
With a cold engine, the glow plug relay and glow
plugs may be activated for a maximum time of 200
seconds. Refer to the following Glow Plug Control
chart for a temperature/time comparison of glow plug
relay operation.In this chart, Pre±Heat and Post±Heat times are
mentioned. Pre±heat is the amount of time the glow
plug relay circuit is activated when the ignition (key)
switch is ON, but the engine has yet to be started.
Post±heat is the amount of time the glow plug relay
circuit is activated after the engine is operating. The
Glow Plug lamp will not be illuminated during the
post±heat cycle.
GLOW PLUGS
Glow plugs are used to help start a cold or cool
engine. The plug will heat up and glow to heat the
combustion chamber of each cylinder. An individual
plug is used for each cylinder. Each plug is threaded
into the cylinder head above the fuel injector (Fig. 12).
Each plug will momentarily draw approximately 25
amps of electrical current during the initial key±on
cycle. This is on a cold or cool engine. After heating,
Fig. 11 Glow Plug Relay Location
GLOW PLUG CONTROL
Fig. 12 Glow Plug
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 49
DESCRIPTION AND OPERATION (Continued)
Page 1418 of 1938

the current draw will drop to approximately 9±12
amps per plug.
Total momentary current draw for all four plugs is
approximately 100 amps on a cold engine dropping to
a total of approximately 40 amps after the plugs are
heated.
Electrical operation of the glow plugs are con-
trolled by the glow plug relay. Refer to the previous
Glow Plug RelayÐPCM Output for additional infor-
mation.
EXHAUST GAS RECIRCULATION (EGR)
SOLENOIDÐPCM OUTPUT
This circuit controls operation of the Exhaust Gas
Recirculation (EGR) solenoid. The EGR solenoid (Fig.
11) controls operation of the EGR valve.
Refer to Group 25, Emission Control System for
information. See EGR solenoid.
DIAGNOSIS AND TESTING
DIESEL DIAGONSTICS
The PCM controller does engine off diagonstics
tests, which may be heard for about 60 seconds after
turning the key off.
DIESEL PCM RELAY TEST
To perform a test of the relay and its related cir-
cuitry, refer to the DRB scan tool. To test the relay
only, refer to RelaysÐOperation/Testing in this sec-
tion of the group.
Diagnostic Trouble Codes:Refer to On-Board
Diagnostics in Group 25, Emission Control System
for a list of Diagnostic Trouble Codes (DTC's) for cer-
tain fuel system components.
ENGINE SPEED SENSOR TEST
To perform a test of the engine speed sensor and
its related circuitry, refer to the DRB scan tool.
Diagnostic Trouble Codes:Refer to On-Board
Diagnostics in Group 25, Emission Control System
for a list of Diagnostic Trouble Codes (DTC's) for cer-
tain fuel system components.
ENGINE COOLANT TEMPERATURE SENSOR TEST
The sensor is located on the side of cylinder head
near the rear of fuel injection pump (Fig. 13).
For a list of Diagnostic Trouble Codes (DTC's) for
certain fuel system components, refer to On-Board
Diagnostics in Group 25, Emission Control System.
To test the sensor only, refer to the following:
(1) Disconnect wire harness connector from coolant
temperature sensor.
(2) Test the resistance of the sensor with a high
input impedance (digital) volt±ohmmeter. The resis-
tance (as measured across the sensor terminals)should be less than 1340 ohms with the engine
warm. Refer to the following Sensor Resistance
(OHMS) chart. Replace the sensor if it is not within
the range of resistance specified in the chart.
(3) Test continuity of the wire harness. Do this
between the PCM wire harness connector and the
sensor connector terminal. Also test continuity of
wire harness to the sensor connector terminal. Refer
Fig. 13 Engine Coolant Temperature Sensor
Location
SENSOR RESISTANCE (OHMS)
14 - 50 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)
Page 1419 of 1938

to Group 8W for wiring connector and circuitry infor-
mation. Repair the wire harness if an open circuit is
indicated.
(4) After tests are completed, connect electrical
connector to sensor.
GLOW PLUG TEST
Hard starting or a rough idle after starting may be
caused by one or more defective glow plugs. Before
testing the glow plugs, a test of the glow plug relay
should be performed. This will ensure that 12V+ is
available at the plugs when starting the engine.
Refer to the Glow Plug Relay Test for information.
For accurate test results, the glow plugs should be
removed from the engine. The plugs must be checked
when cold.Do not check the plugs if the engine
has recently been operated. If plugs are
checked when warm, incorrect amp gauge
readings will result.
Use Churchill Glow Plug Tester DX.900 or an
equivalent (Fig. 14) for the following tests. This
tester is equipped with 4 timer lamps.
(1) Remove the glow plugs from the engine. Refer
to Glow Plug Removal/Installation.
(2) Attach the red lead of the tester to the 12V+
(positive) side of the battery.
(3) Attach the black lead of the tester to the 12V±
(negative) side of the battery.
(4) Fit the glow plug into the top of the tester and
secure it with the spring loaded bar (Fig. 14).
(5) Attach the third lead wire of the tester to the
electrical terminal at the end of the glow plug.(6) When performing the test, the tester button
(Fig. 14) should be held continuously without release
for 20 seconds as indicated by the 4 timer lamps.
Each illuminated lamp represents a 5 second time
lapse.
(a) Press and hold the tester button (Fig. 14)
and note the amp gauge reading. The gauge read-
ing should indicate a momentary, initial current
draw (surge) of approximately 25 amps. After the
initial surge, the amp gauge reading should begin
to fall off. The glow plug tip should start to glow
an orange color after 5 seconds. If the tip did not
glow after 5 seconds, replace the glow plug. Before
discarding the glow plug, check the position of the
circuit breaker on the bottom of the plug tester. It
may have to be reset. Reset if necessary.
(b) Continue to hold the tester button while
observing the amp gauge and the 4 timer lamps.
When all 4 lamps are illuminated, indicating a 20
second time lapse, the amp gauge reading should
indicate a 9±12 amp current draw. If not, replace
the glow plug. Refer to Glow Plug Removal/Instal-
lation.
(7) Check each glow plug in this manner using one
20 second cycle. If the glow plug is to be retested, it
must first be allowed to cool to room temperature.
WARNING: THE GLOW PLUG WILL BECOME
EXTREMELY HOT (GLOWING) DURING THESE
TESTS. BURNS COULD RESULT IF IMPROPERLY
HANDLED. ALLOW THE GLOW PLUG TO COOL
BEFORE REMOVING FROM TESTER.
(8) Remove the glow plug from the tester.
GLOW PLUG RELAY TEST
The glow plug relay is located in the engine com-
partment on the left±inner fender (Fig. 15).
When the ignition (key) switch is placed in the ON
position, a signal is sent to the PCM relating current
engine coolant temperature. This signal is sent from
the engine coolant temperature sensor.
After receiving this signal, the PCM will deter-
mine if, when and for how long a period the glow
plug relay should be activated. This is done before,
during and after the engine is started. Whenever the
glow plug relay is activated, it will control the 12V+
100 amp circuit for the operation of the four glow
plugs.
The Glow Plug lamp is tied to this circuit. Lamp
operation is also controlled by the PCM.
With a cold engine, the glow plug relay and glow
plugs may be activated for a maximum time of 200
seconds. Refer to the Glow Plug Control chart for a
temperature/time comparison of glow plug relay oper-
ation.
Fig. 14 Typical Glow Plug Tester
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 51
DIAGNOSIS AND TESTING (Continued)
Page 1422 of 1938

(2) Remove the sensor mounting bolts.
(3) Remove the sensor.
INSTALLATION
(1) Install the sensor flush against the opening in
the transmission housing.
(2) Install and tighten the sensor mounting bolt to
19 N´m (14 ft. lbs.) torque.
(3) Connect the electrical connector to the sensor.
ENGINE COOLANT TEMPERATURE SENSOR
The sensor is located on the side of cylinder head
near the rear of fuel injection pump (Fig. 19).
REMOVAL
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
REFER TO GROUP 7, COOLING.
(1) Partially drain cooling system. Refer to Group
7, Cooling.
(2) Disconnect electrical connector from sensor.
(3) Remove sensor from cylinder head.
INSTALLATION
(1) Install a new copper gasket to sensor.
(2) Install sensor to cylinder head.
(3) Tighten sensor to 18 N´m (13 ft. lbs.) torque.
(4) Connect electrical connector to sensor.
(5) Replace any lost engine coolant. Refer to Group
7, Cooling System.
GLOW PLUGS
The glow plugs are located above each fuel injector
(Fig. 20). Four individual plugs are used.
REMOVAL
(1) Disconnect the negative battery cable at the
battery.
(2) Clean the area around the glow plug with com-
pressed air before removal.
(3) Disconnect electrical connector (Fig. 21) at glow
plug.
(4) Remove the glow plug (Fig. 20) from cylinder
head.
Fig. 18 Engine Speed SensorFig. 19 Engine Coolant Temperature Sensor
Location
Fig. 20 Glow Plug
14 - 54 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
REMOVAL AND INSTALLATION (Continued)
Page 1546 of 1938

OPERATION
The gear ratios for the 41TE transaxle are as fol-
lows:
²1stÐ2.84
²2ndÐ1.57
²3rdÐ1.00
²ODÐ0.69
²ReverseÐ2.21
Final Drive Ratio is dependent on which engine
option is selected.
²2.4 Liter: 3.91 FDR
²3.3 Liter: 3.62 FDR
²3.8 Liter: 3.45 FDR
The torque converter clutch is available in 2nd,
direct, or overdrive gear;. The shift lever is conven-
tional with six positions: P, R, N, OD, 3, and L avail-
able. When OD is selected the transaxle shifts
through all four speeds with torque converter clutch
available in overdrive. This position is recommended
for most driving. The 3 position is tailored for use in
hilly or mountainous driving. When 3 is selected, the
transmission uses only 1st, 2nd, and direct gears
with 2nd-direct shift delayed to 40 mph or greater.
When operating in 3 or L positions torque converter
clutch application occurs in direct gear. This
improves transmission cooling under heavy loads. If
high engine coolant temperature occurs, the torque
converter clutch will also engage in 2nd gear. The L
position provides maximum engine braking for
descending steep grades. Unlike most current tran-
saxles, upshifts are provided to 2nd or direct gear at
peak engine speeds if the accelerator is depressed.
This provides engine over-speed protection and max-
imum performance.
FLUID LEVEL AND CONDITION
NOTE: The transmission and differential sump have
a common oil sump with an opening between the
two.
The torque converter fills in both the (P) Park and
(N) Neutral positions. Place the selector lever in (P)
Park to check the fluid level.The engine should be
running at idle speed for at least one minute,
with the vehicle on level ground. This will
assure complete oil level stabilization between
differential and transmission.The fluid should be
at normal operating temperature (approximately 82
C. or 180 F.). The fluid level is correct if it is in the
HOTregion (cross-hatched area) on the oil level indi-
cator.
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.Improper filling can also raise the fluid level too
high. When the transaxle has too much fluid, the
gears churn up foam and cause the same conditions
which occur with a low fluid level.
In either case, the air bubbles can cause overheat-
ing, fluid oxidation, and varnishing. This can inter-
fere with normal valve, clutch, and accumulator
operation. Foaming can also result in fluid escaping
from the transaxle vent where it may be mistaken
for a leak.
Along with fluid level, it is important to check the
condition of the fluid. When the fluid smells burned,
and is contaminated with metal or friction material
particles, a complete transaxle overhaul is needed.
Be sure to examine the fluid on the dipstick closely.
If there is any doubt about its condition, drain out a
sample for a double check.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
SELECTION OF LUBRICANT
It is important that the proper lubricant be used in
the 41TE transaxle. MOPARtATF PLUS 3 (Auto-
matic Transmission FluidÐtype 7176) should be used
to aid in assuring optimum transmission perfor-
mance. Fluids of the type labeled DEXRON II Auto-
matic Transmission Fluid arenot recommended.It
is important that the transmission fluid be main-
tained at the prescribed level using the recommended
fluids.
SPECIAL ADDITIVES
Chrysler Corporation does not recommend the
addition of any fluids to the transaxle, other than the
fluid listed above. An exception to this policy is the
use of special dyes to aid in detecting fluid leaks. The
use of transmission sealers should be avoided, since
they may adversely affect seals.
DESCRIPTION AND OPERATION
CLUTCH AND GEAR
The transaxle consists of:
²Three multiple disc input clutches
²Two multiple disc grounded clutches
²Four hydraulic accumulators
²Two planetary gear sets
This provides four forward ratios and a reverse
ratio. The input clutch-apply pistons were designed
with centrifugally balanced oil cavities so that quick
response and good control can be achieved at any
speed. A push/pull piston is incorporated for two of
the three input clutches.
21 - 72 TRANSAXLE AND POWER TRANSFER UNITNS
GENERAL INFORMATION (Continued)
Page 1818 of 1938

GENERAL INFORMATION
INTRODUCTION
Both the heater and the heater/air conditioning
systems share many of the same components. This
group will deal with both systems together when
component function is common, and separately when
they are not.
For proper operation of the instrument panel con-
trols, refer to the Owner's Manual provided with the
vehicle.
All vehicles are equipped with a common A/C-
heater unit housing assembly. When the vehicle has
only a heater system, the evaporator and recirculat-
ing air door are omitted.
An optional zone control HVAC unit is available.
This unit has dual blend-air doors that can be regu-
lated independently of each other. The temperature
setting can be different from driver's side to passen-
ger side. There is also a rear (aux.) heating and A/C
system available when the vehicle is equipped with
zone control.
SAFETY PRECAUTIONS AND WARNINGS
WARNING: WEAR EYE PROTECTION WHEN SER-
VICING THE AIR CONDITIONING REFRIGERANT
SYSTEM. SERIOUS EYE INJURY CAN RESULT
FROM EYE CONTACT WITH REFRIGERANT. IF EYE
CONTACT IS MADE, SEEK MEDICAL ATTENTION
IMMEDIATELY.
DO NOT EXPOSE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN
REFRIGERANT IS BURNED. AN ELECTRONIC TYPE
LEAK DETECTOR IS RECOMMENDED.
LARGE AMOUNTS OF REFRIGERANT RELEASED
IN A CLOSED WORK AREA WILL DISPLACE THE
OXYGEN AND CAUSE SUFFOCATION.
THE EVAPORATION RATE OF REFRIGERANT AT
AVERAGE TEMPERATURE AND ALTITUDE IS
EXTREMELY HIGH. AS A RESULT, ANYTHING THAT
COMES IN CONTACT WITH THE REFRIGERANT
WILL FREEZE. ALWAYS PROTECT SKIN OR DELI-
CATE OBJECTS FROM DIRECT CONTACT WITH
REFRIGERANT. R-134a SERVICE EQUIPMENT OR
VEHICLE A/C SYSTEM SHOULD NOT BE PRES-
SURE TESTED OR LEAK TESTED WITH COM-
PRESSED AIR.
SOME MIXTURES OF AIR and R-134a HAVE BEEN
SHOWN TO BE COMBUSTIBLE AT ELEVATED
PRESSURES. THESE MIXTURES ARE POTENTIALLY
DANGEROUS AND MAY RESULT IN FIRE OR
EXPLOSION CAUSING INJURY OR PROPERTY
DAMAGE.
ANTIFREEZE IS AN ETHYLENE GLYCOL BASE
COOLANT AND IS HARMFUL IF SWALLOWED ORINHALED. SEEK MEDICAL ATTENTION IMMEDI-
ATELY IF SWALLOWED OR INHALED. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN AND PETS.
DO NOT OPEN A COOLING SYSTEM WHEN THE
ENGINE IS AT RUNNING TEMPERATURE. PER-
SONAL INJURY CAN RESULT.
CAUTION: The engine cooling system is designed
to develop internal pressure of 97 to 123 kPa (14 to
18 psi). Allow the vehicle to cool a minimum of 15
minutes before opening the cooling system. Refer
to Group 7, Cooling System.
DESCRIPTION AND OPERATION
AIR DISTRIBUTION DUCTS
The air distribution ducts for the A/C, Heater,
Defroster, and Second Seating Air Distribution are
not serviceable in vehicle. The procedures for service
of these ducts are covered in Group 8E, Instrument
Panel and Gauges.
The only ducts that are serviceable in the vehicle
are the side window demister ducts and the ducts
that feed the front door outlets for the first rear pas-
senger(s) seating. To service the door ducts refer to
Group 23, Body.
A/C PRESSURE TRANSDUCER
The A/C Pressure Transducer (Fig. 1) monitors the
refrigerant gas pressure on the high side of the sys-
tem. The transducer is located on the liquid line. The
pressure transducer turns off the voltage to the com-
pressor clutch coil when refrigerant gas pressure
drops to levels that could damage the compressor.
The transducer also is used to adjust condenser fan
speeds and will turn off compressor at high refriger-
ant pressures. The pressure transducer is a sealed
factory calibrated unit. It must be replaced if defec-
tive. O-ring replacement is required whenever the
pressure transducer is serviced. Be sure to use the
O-ring specified for the transducer.
A/C SERVICE PORTS
The A/C service port valve cores are located within
the A/C lines (Fig. 2). The High Side (Discharge)
valve service port is located on the liquid line near
the right frame rail. The Low Side (Suction) valve
service port is located on the suction line near the
compressor.
24 - 2 HEATING AND AIR CONDITIONINGNS
Page 1831 of 1938

be 21ÉC to 27ÉC (70ÉF to 85ÉF). To test the expansion
valve:
NOTE: Liquid CO2 is required to test the expansion
valve. It is available from most welding supply facil-
ities. CO2 is also available from companies which
service and sell fire extinguishers.
(1) Connect a charging station or manifold gauge
set to the refrigerant system service ports. Verify the
refrigerant charge level.
(2) Close all doors, windows and vents to the pas-
senger compartment.
(3) Set heater A/C control to A/C, full heat,
FLOOR, and high blower.
(4) Start the engine and allow to idle (1000 rpm).
After the engine has reached running temperature,
allow the passenger compartment to heat up. This
will create the need for maximum refrigerant flow
into the evaporator.
(5) If the refrigerant charge is sufficient, discharge
(high pressure) gauge should read 965 to 1655 kPa
(140 to 240 psi). Suction (low pressure) gauge should
read 140 kPa to 207 kPa (20 psi to 30 psig). If system
cannot achieve proper pressure readings, replace the
expansion valve. If pressure is correct, proceed with
test.
WARNING: PROTECT SKIN AND EYES FROM CON-
TACTING CO2 PERSONAL INJURY CAN RESULT.
(6) If suction side low pressure is within specified
range, freeze the expansion valve control head for 30
seconds. Use a super cold substance (liquid CO2).Do
not spray R-134a or R-12 Refrigerant on the
expansion valve for this test.Suction side low
pressure should drop by 10 psi. If not, replace expan-
sion valve.
(7) Allow expansion valve to thaw. The low pres-
sure gauge reading should stabilize at 140 kPa to
240 kPa (20 psi to 30 psig). If not, replace expansion
valve.
(8) When expansion valve test is complete, test
A/C overall performance. Remove all test equipment
before returning vehicle to use.
HEATER PERFORMANCE TEST
PRE-DIAGNOSTIC PREPARATIONS
Review Safety Precautions and Warnings in this
group before performing the following procedures.
Check the coolant level, drive belt tension, vacuum
line connections, radiator air flow and fan operation.
Start engine and allow to warm up to normal tem-
perature.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 cap. Place a rag over the cap and
turn it to the first safety stop. Allow pressure to
escape through the overflow tube. When the system
stabilizes, remove the cap completely.
MAXIMUM HEATER OUTPUT: TEST AND
ACTION
Engine coolant is provided to the heater system by
two 16 mm (5/8 inch inside diameter) heater hoses.
With engine idling at normal running temperature,
set the control to maximum heat, floor, and high
blower setting. Using a test thermometer, check the
air temperature coming from the floor outlets, refer
to Temperature Reference Table.
If the floor outlet air temperature is insufficient,
refer to Group 7, Cooling Systems for specifications.
Both heater hoses should be HOT to the touch (cool-
ant return hose should be slightly cooler than the
supply hose). If coolant return hose is much cooler
than the supply hose, locate and repair engine cool-
ant flow obstruction in heater system.
POSSIBLE LOCATIONS OR CAUSE OF
OBSTRUCTED COOLANT FLOW
(1) Pinched or kinked heater hoses.
(2) Improper heater hose routing.
(3) Plugged heater hoses or supply and return
ports at cooling system connections, refer to Group 7,
Cooling System.
(4) Plugged heater core.
(5) Air locked heater core.
(6) If coolant flow is verified and outlet tempera-
ture is insufficient, a mechanical problem may exist.
POSSIBLE LOCATION OR CAUSE OF
INSUFFICIENT HEAT
(1) Obstructed cowl air intake.
(2) Obstructed heater system outlets.
(3) Blend-air door not functioning properly.
TEMPERATURE REFERENCE TABLE
AMBIENT
TEMPERATUREMINIMUM 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
NSHEATING AND AIR CONDITIONING 24 - 15
DIAGNOSIS AND TESTING (Continued)
Page 1832 of 1938

TEMPERATURE CONTROL
If temperature cannot be adjusted with the TEMP
lever on the control panel, the following could require
service:
(1) Blend-air door binding.
(2) Faulty blend-air door motor.
(3) Improper engine coolant temperature.
(4) Faulty Instrument Panel Control.
SYSTEM CHARGE LEVEL TEST
The procedure below should be used to check
and/or fill the refrigerant charge in the air condition-
ing system.
NOTE: The amount of R134a refrigerant that the air
conditioning system holds is:
²Without rear A/C± .96 kg (34 oz. or 2.13 lbs.)
²With Rear A/C± 1.36 kg (48 oz. or 3.00 lbs.)
NOTE: Low Charge, condition may be described
as:
²Loss of A/C performance
²Fog from A/C outlets
²evaporator may have a HISS sound
There are two different ways the system can be
tested:
²With a scan tool (DRB), thermocouple and the
Charge Determination Graph. Use the scan tool
(DRB) diagnostic topic: Engine±System Monitors, A/C
Pressure.
²Using a manifold gauge set, a thermocouple and
the Charge Determination Graph.
It is recommended to use the gauges or reclaim/re-
cycle equipment.
WARNING: AVOID BREATHING A/C REFRIGERANT
AND LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SER-
VICE.
R-134a SERVICE EQUIPMENT OR VEHICLE A/C
SYSTEM SHOULD NOT BE PRESSURE TESTED OR
LEAK TESTED WITH COMPRESSED AIR. SOME
MIXTURES OF AIR/R-134a HAVE BEEN SHOWN TO
BE COMBUSTIBLE AT ELEVATED PRESSURES.
THESE MIXTURES ARE POTENTIALLY DANGER-
OUS AND MAY RESULT IN FIRE OR EXPLOSION
CAUSING INJURY OR PROPERTY DAMAGE.
(1) Establish your preferred method of measuring
liquid line pressure. Use a manifold gauge set or a
DRB scan tool.(2) Attach a clamp-on thermocouple (P.S.E. 66-324-
0014 or 80PK-1A) or equivalent to the liquid line. It
must be placed as close to the A/C Pressure Trans-
ducer as possible to observe liquid line temperature.
Refer to ªThermocouple Probeº in this section for
more information on probe.
(3) The vehicle must be in the following modes:
²Transaxle in Park
²Engine Idling at 700 rpm
²A/C Controls Set to Outside Air
²Panel Mode
²Full Cool
²High Blower motor, (vehicle equipped with rear
A/C turn rear blower motor ON HIGH)
²A/C Button in the ON position
²Vehicle Windows Open.
²Recirc. button turned OFF
(4) Operate system for a couple of minutes to allow
the system to stabilize.
(5) Set system pressure to about 1793 kPa (260
psi) by placing a piece of cardboard over part of the
front side of the condenser. To place cardboard prop-
erly, remove the upper radiator-condenser cover.
Insert cardboard between condenser and radiator
front. This will maintain a constant pressure.
(6) Observe Liquid Line pressure and Liquid line
temperature. Using theCharge Determination
Chartdetermine where the system is currently oper-
ating. If the system is in the undercharged region,
ADD 0.057 Kg. (2 oz.) to the system and recheck
readings. If the system is in the overcharged region,
RECLAIM 0.057 Kg. (2 oz.) from the system and
recheck readings. Continue this process until the sys-
tem readings are in the proper charge area on the
Charge Determination Chart.
(7) The same procedure can be performed using
the scan tool (DRB). To determine liquid line pres-
sure, attach the scan tool, go to System Moni-
tors±A/C Pressure. Observe liquid line pressure from
A/C Pressure Transducer on digital display and digi-
tal thermometer. Refer toCharge Determination
Chartand determine where the system is operating.
SERVICE PROCEDURES
R-134a REFRIGERANT
This vehicle uses a new type of refrigerant called
R-134a. It is a non-toxic, non-flammable, clear color-
less liquefied gas.
R-134a refrigerant is not compatible with R-12
refrigerant in an air conditioning system. Even a
small amount of R-12 in a R-134a system could cause
compressor failure, refrigerant oil to sludge and/or
poor performance.Never add any other type of
refrigerant to a system designed to use R-134a
refrigerant. System failure will occur.
24 - 16 HEATING AND AIR CONDITIONINGNS
DIAGNOSIS AND TESTING (Continued)
Page 1865 of 1938

NOTE: If the heater core was emptied and was not
prefilled, it is necessary to thermal cycle the vehicle
TWICE. The heater core is positioned higher than
the radiator fill cap. Therefore the heater core will
not gravity fill to level. To thermal cycle the vehicle,
it must be operated till the thermostat opens, then
turned off and allowed to cool. In order to verify
that the auxiliary unit is filled completely, the follow-
ing procedure can be used:
²Vehicle at room temperature.
²Engine is brought up to operating temperature.
²Front unit is OFF, temperature slides are at full
HEAT position.
²Engine is at idle.
²With rear blower motor ON HIGH
²Discharge air temperature, measured at the
dual register located on the C-pillar base, is between
57ÉC to 62ÉC (135É and 145É F).
REAR HEATER LINES
REMOVAL
NOTE: Review Safety Precautions and Warnings
before proceeding with this operation.
(1) Partially drain engine cooling system. Refer to
Group 7, Engine Cooling.
(2) Loosen clamp at the front end of the hose
located at the right, outboard side of the underbody,
rearward of the front crossmember. (Fig. 2)
(3) Carefully rotate hose back and forth while tug-
ging slightly away from connector nipple. If the hose
will not come off, slice the hose at the connector nip-
ple and peel off heater hose. This method will require
heater hose replacement.
CAUTION: When removing hoses from outlet nip-
ples, do not use excessive force. Outlet nipples
may become damaged and leak engine coolant.
(4) Compress insert in rear heater hose quick con-
nection and pull downward on hose. (Fig. 4)(5) Remove (3) straps securing underbody lines.
(Fig. 1)
(6) Separate and remove rear heater lines from
vehicle.
INSTALLATION
For installation, reverse the above procedures.
MODE DOOR
REMOVAL
(1) Remove A/C unit.
(2) Place unit on bench.
(3) Remove heater core.
(4) Remove blower scroll.
(5) Remove evaporator cover.
(6) Remove A/C line to expansion valve mounting
nut.
(7) Carefully pull evaporator out of housing.
(8) Remove mode door actuator and gear exten-
sion.
(9) Remove Heater-A/C housing clips and screws.
(10) Separate housing halves.
(11) Remove mode door.
INSTALLATION
For installation, reverse the above procedures.
MODE DOOR ACTUATOR
REMOVAL
(1) Remove A/C unit.
(2) Place unit on bench.
(3) Remove mode door actuator connector.
(4) Remove mode door actuator mounting screws
and remove actuator.
INSTALLATION
For installation, reverse the above procedures.
NSHEATING AND AIR CONDITIONING 24 - 49
REMOVAL AND INSTALLATION (Continued)
Page 1868 of 1938

SAFETY PRECAUTIONS AND WARNINGS
WARNING: WEAR EYE PROTECTION WHEN SER-
VICING THE AIR CONDITIONING REFRIGERANT
SYSTEM. SERIOUS EYE INJURY CAN RESULT
FROM EYE CONTACT WITH REFRIGERANT. IF EYE
CONTACT IS MADE, SEEK MEDICAL ATTENTION
IMMEDIATELY.
DO NOT EXPOSE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN
REFRIGERANT IS BURNED. AN ELECTRONIC TYPE
LEAK DETECTOR IS RECOMMENDED.
LARGE AMOUNTS OF REFRIGERANT RELEASED
IN A CLOSED WORK AREA WILL DISPLACE THE
OXYGEN AND CAUSE SUFFOCATION.
THE EVAPORATION RATE OF REFRIGERANT AT
AVERAGE TEMPERATURE AND ALTITUDE IS
EXTREMELY HIGH. AS A RESULT, ANYTHING THAT
COMES IN CONTACT WITH THE REFRIGERANT
WILL FREEZE. ALWAYS PROTECT SKIN OR DELI-
CATE OBJECTS FROM DIRECT CONTACT WITH
REFRIGERANT. R-134a SERVICE EQUIPMENT OR
VEHICLE A/C SYSTEM SHOULD NOT BE PRES-
SURE TESTED OR LEAK TESTED WITH COM-
PRESSED AIR.
SOME MIXTURES OF AIR and R-134a HAVE BEEN
SHOWN TO BE COMBUSTIBLE AT ELEVATED
PRESSURES. THESE MIXTURES ARE POTENTIALLY
DANGEROUS AND MAY RESULT IN FIRE OR
EXPLOSION CAUSING INJURY OR PROPERTY
DAMAGE.
ANTIFREEZE IS AN ETHYLENE GLYCOL BASE
COOLANT AND IS HARMFUL IF SWALLOWED OR
INHALED. SEEK MEDICAL ATTENTION IMMEDI-
ATELY IF SWALLOWED OR INHALED. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN AND PETS.
DO NOT OPEN A COOLING SYSTEM WHEN THE
ENGINE IS AT RUNNING TEMPERATURE. PER-
SONAL INJURY CAN RESULT.
CAUTION: The engine cooling system is designed
to develop internal pressure of 97 to 123 kPa (14 to
18 psi). Allow the vehicle to cool a minimum of 15
minutes before opening the cooling system. Refer
to Group 7, Cooling System.
DESCRIPTION AND OPERATION
AIR DISTRIBUTION DUCTS
The air distribution ducts for the A/C, Heater,
Defroster, and Second Seating Air Distribution arenot serviceable in vehicle. The procedures for service
of these ducts are covered in Group 8E, Instrument
Panel and Gauges.
The only ducts that are serviceable in the vehicle
are the side window demister ducts and the ducts
that feed the front door outlets for the first rear pas-
senger(s) seating. To service the door ducts refer to
Group 23, Body.
A/C PRESSURE TRANSDUCER
The A/C Pressure Transducer (Fig. 1) monitors the
refrigerant gas pressure on the high side of the sys-
tem. The transducer is located on the liquid line. The
pressure transducer turns off the voltage to the com-
pressor clutch coil when refrigerant gas pressure
drops to levels that could damage the compressor.
The transducer also is used to adjust condenser fan
speeds and will turn off compressor at high refriger-
ant pressures. The pressure transducer is a sealed
factory calibrated unit. It must be replaced if defec-
tive. O-ring replacement is required whenever the
pressure transducer is serviced. Be sure to use the
O-ring specified for the transducer.
A/C SERVICE PORTS
The A/C service port valve cores are located within
the A/C lines. The High Side (Discharge) valve ser-
vice port is located on the liquid line near the right
strut tower. The Low Side (Suction) valve service
port is located on the suction line near the compres-
sor.
The High Side service port is a two piece port and
is serviceable. The Low Side service port is not ser-
viceable, and the suction line would have to be
replaced.
COMPRESSOR
The A/C compressor for the 2.5L Turbo Diesel, is
located on the front side of the engine block. It is
mounted to the engine block by four bolts. The com-
Fig. 1 A/C Pressure Transducer
24 - 2 HEATING AND AIR CONDITIONINGNS/GS
GENERAL INFORMATION (Continued)