INSTALLATION - HEATER CORE
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 - HEATER PLUMB-
ING).
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) While pushing the brake pedal downward (Fig.
20) and pulling the accelerator pedal upward (Fig.
19) far enough for clearance, slide the heater core
into the distribution housing.
(2) Install and tighten the two screws that secure
the heater core mounting plate to the distribution
housing (Fig. 18). Tighten the screws to 2 N´m (17 in.
lbs.).
(3) Remove the plugs or tape from the heater core
tube fittings and both heater core ports.
(4) Position both heater core tubes and the sealing
plate simultaneously to the heater core supply and
return ports.
(5) The heater core tubes each have a slot that
must be indexed to a location tab within each of the
heater core ports. Adjust the position of the tubes as
required so that the sealing plate fits flush against
the heater core supply and return ports, which indi-
cates that the tubes are properly indexed.
(6) Install and tighten the screw that secures the
heater core tube sealing plate to the heater core sup-
ply and return ports. Tighten the screw to 3 N´m (27
in. lbs.).
(7) Position the heater core shield onto the distri-
bution housing. Be certain that the two location tabs
on the front of the shield are engaged in the recepta-
cles in the two lower finger formations of the evapo-
rator housing near the dash panel (Fig. 17).
(8) Install and tighten the three screws that secure
the heater core shield to the left end of the HVAC
distribution housing. Tighten the screws to 2 N´m (17
in. lbs.).(9) Reconnect the power brake booster input rod
(push rod) to the pin on the brake pedal arm. (Refer
to 5 - BRAKES - ABS/HYDRAULIC/MECHANICAL/
POWER BRAKE BOOSTER - INSTALLATION).
(10) Reinstall the brake lamp switch into its
mounting bracket. (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - INSTALLATION).
(11) Reinstall the silencer boot around the base of
the lower steering shaft on the dash panel.
(12) Reconnect the battery negative cable.
(13) Refill the engine cooling system. (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
(14) Operate sustem for two thermostat cycles to
assure elimination of air in the system.
HEATER HOSE
REMOVAL
There are several heater core plumbing configura-
tions used on this model, depending upon the engine
size and other optional equipment. One plumbing
configuration is used for all 2.4L engines (Fig. 21),
while the 3.3L and 3.8L engines have unique heater
return plumbing on the engine for models with or
without an optional engine oil cooler (Fig. 24) or (Fig.
25). There are also unique plumbing configurations
at the heater core for models with or without the
optional rear heater and air conditioner (Fig. 22) or
(Fig. 23). All models use a combination of formed
steel tubing and rubber hoses. In most cases, the
rubber hose is secured to the steel tubing with a
spring tension clamp.
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 - HEATER PLUMB-
ING).
(1) Drain the engine cooling system. (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(2) Using spring tension clamp pliers, compress
and slide the clamps that secure each end of the
heater hose to the tube or nipple toward the center of
the hose to be removed. Release the clamp when it is
off of the tube or nipple.
24 - 80 PLUMBING - FRONTRS
HEATER CORE (Continued)
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REFRIGERANT
DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM CHARGE LEVEL 2.5L DIESEL
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).
NOTE: The proper amount of R-134a refrigerant for
the refrigerant system in this model is:
²Single or Dual Zone (Front Unit Only - 2.5L Die-
sel) ± 0.91 kilograms (2.00 pounds or 32 ounces)
²Single or Dual Zone (Front Unit Only) - 0.96
kilograms (2.13 pounds or 34 ounces)
²Three Zone (Front and Rear Units) - 1.31 kilo-
grams (2.88 pounds or 46 ounces)
The procedure that follows should be used to deter-
mine whether the refrigerant system contains the
proper refrigerant charge. Symptoms of an improper
refrigerant charge (low) include: poor air conditionerperformance, fog emitted from the air conditioner out-
lets, a hissing sound from the expansion valve/evapo-
rator area. There are two different methods with
which the refrigerant charge level may be tested:
²Using a DRBIIItscan tool, a thermocouple and
the Charge Determination Chart (Fig. 3). Refer to
the appropriate diagnostic information.
²Using a manifold gauge set, a thermocouple and
the Charge Determination Chart (Fig. 3).
A temperature probe is required to measure liquid
line temperature. The clamp-on, Type K thermocou-
ple temperature probe used in this procedure is
available through the DaimlerChrysler Professional
Service Equipment (PSE) program. This probe (PSE
#66-324-0014 or #80PK-1A) is compatible with tem-
perature-measuring instruments that accept Type K
thermocouples, and have a miniature connector
input. Other temperature probes are available
through aftermarket sources; however, all references
in this procedure will reflect the use of the probe
made available through the PSE program.
In order to use the temperature probe, a digital ther-
mometer will also be required. If a digital thermometer
is not available, an adapter is available through the
PSE program that will convert any standard digital
multimeter into a digital thermometer. This adapter is
designed to accept any standard Type K thermocouple.
If a digital multimeter is not available, this tool is also
available through the PSE program.
NOTE: When connecting the service equipment
couplings to the refrigerant system service ports,
be certain that the valve of each coupling is fully
closed. This will reduce the amount of effort
required to make the connection.
(1) Remove the caps from the refrigerant system
service ports and attach a manifold gauge set or a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 to the refriger-
ant system.
(2) Attach a clamp-on thermocouple to the liquid
line. The thermocouple must be placed as close to the
A/C pressure transducer as possible to accurately
observe liquid line temperature.
(3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run at idle under the following condi-
tions for five minutes.
(a) Front windows are open.
(b) Transaxle in Park.
(c) Front heater-A/C controls set to outside air,
full cool, panel mode, blower high, and compressor
engaged.
(d)
If the vehicle is so equipped, the rear heater-
A/C controls must be set to full cool and blower high.
Fig. 2 AIR INTAKE AND HEATER PIPE ASSEMBLY
1 - INTAKE TUBE AIR INTAKE
2 - INTAKE PIPE
3 - RETAINING SCREWS
4 - INTAKE HEATER LINE
5 - RETURN HEATER LINE
24a - 4 HEATING & AIR CONDITIONINGRG
HEATER PIPES - DIESEL SUPPLEMENTAL HEATER (Continued)
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EXHAUST GAS RECIRCULATION
TABLE OF CONTENTS
page page
EXHAUST GAS RECIRCULATION
DESCRIPTION............................3
OPERATION.............................3
VA LV E
DESCRIPTION............................3
OPERATION.............................4REMOVAL...............................4
INSTALLATION............................4
VALVE COOLER
DESCRIPTION............................4
REMOVAL...............................4
INSTALLATION............................5
EXHAUST GAS
RECIRCULATION
DESCRIPTION
The EGR system reduces oxides of nitrogen (NOx)
in the engine exhaust. This is accomplished by allow-
ing a predetermined amount of hot exhaust gas to
recirculate and dilute the incoming fuel/air mixture.
A malfunctioning EGR system can cause engine
stumble, sags, or hesitation, rough idle, engine stall-
ing and poor driveability.
OPERATION
The system consists of:
²An EGR valve assembly. The valve is located on
the rear of the engine above the exhaust manfiold.
²An EGR solenoid.The EGR solenoid controls the
ªon timeº of the EGR valve.
²The ECM operates the EGR solenoid. The ECM
is located inside the vehicle under the instrument
panel.
²An EGR tube connects a passage in the EGR
valve to the rear of the exhaust manifold.
²The vacuum pump supplies vacuum for the EGR
solenoid and the EGR valve. This pump also supplies
vacuum for operation of the power brake boosterb
and the heating and air conditioning system. The
pump is located internally in the front of the engine
block and is driven by the crankshaft gear.
²Vacuum lines and hoses connect the various
components.
When the ECM supplies a variable ground signal
to the EGR solenoid, EGR system operation starts to
occur. The ECM will monitor and determine when tosupply and remove this variable ground signal. This
will depend on inputs from the engine coolant tem-
perature, throttle position and engine speed sensors.
When the variable ground signal is supplied to the
EGR solenoid, vacuum from the vacuum pump will
be allowed to pass through the EGR solenoid and on
to the EGR valve with a connecting hose.
Exhaust gas recirculation will begin in this order
when:
²The ECM determines that EGR system opera-
tion is necessary.
²The engine is running to operate the vacuum
pump.
²A variable ground signal is supplied to the EGR
solenoid.
²Variable vacuum passes through the EGR sole-
noid to the EGR valve.
²The inlet seat (poppet valve) at the bottom of
the EGR valve opens to dilute and recirculate
exhaust gas back into the intake manifold.
The EGR system will be shut down by the ECM
after 60 seconds of continuous engine idling to
improve idle quality.
VA LV E
DESCRIPTION
The EGR system consists of (Fig. 1):
²EGR valve
²EGR tube
²Vacuum hoses
²EGR cooler
²EGR solenoid
RGEXHAUST GAS RECIRCULATION25a-3
ProCarManuals.com
ON-BOARD DIAGNOSTICS
TABLE OF CONTENTS
page
ON-BOARD DIAGNOSTICS
DESCRIPTION............................6
ON-BOARD DIAGNOSTICS
DESCRIPTION - DIAGNOSTIC TROUBLE CODES
On the following pages, a list of DTC's is provided
for the 2.5L diesel engine. A DTC indicates that the
ECM has recognized an abnormal signal in a circuit
or the system. A DTC may indicate the result of a
failure, but most likely will not identify the failed
component directly. Refer to the appropriate diagnos-
tic manual for more information on diagnosis of trou-
ble codes.
ACCESSING DIAGNOSTIC TROUBLE CODES
A stored DTC can be displayed through the use of
the DRB IIItscan tool. The DRB IIItconnects to the
data link connector. The data link connector is
located under the instrument panel near bottom of
the steering column (Fig. 1).
ERASING TROUBLE CODES
After the problem has been repaired, use the DRB
IIItscan tool to erase a DTC.
ENGINE CONTROL MODULE (ECM) - DRBIIITCODES
Generic Scan Tool Code DRB IIITScan Tool Display
P0070 Ambient Air Temperature Circuit Signal Voltage Too High
Ambient Air Temperature Circuit Signal Voltage Too Low
P0100 Mass Air Flow Sensor Plausibility
Mass Air Flow Sensor Plausibility Positive Area
Mass Air Flow Sensor Signal Voltage Too High
Mass Air Flow Sensor Signal Voltage Too Low
Mass Air Flow Sensor Supply Voltage Too High Or Low
P0105 Barometric Pressure Circuit Signal Voltage To High
Barometric Pressure Circuit Signal Voltage To Low
P0110 Intake Air Temperature Sensor Circuit Signal Too High
Intake Air Temperature Sensor Circuit Signal Too Low
Fig. 1 DATA LINK CONNECTOR
25a - 6 ON-BOARD DIAGNOSTICSRG
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