coolant CHRYSLER CARAVAN 2005 Service Manual

(9) Use absorbent toweling to clean up any engine
coolant spills from the preceding operation.
(10) Release the four latch tabs that secure the
heater core into the rear HVAC housing.
(11) Carefully pull the heater core straight out of
the rear HVAC housing.
(12) Use absorbent toweling to clean up any
engine coolant spills from the preceding operation.
INSTALLATION
NOTE: If the rear heater core or the rear HVAC
housing have been removed from the vehicle for
service, the rear heater core may be pre-filled with
the proper engine coolant mixture prior to recon-
necting the heater hoses to the heater core hose fit-
tings (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - REAR/HEATER CORE - STANDARD
PROCEDURE - HEATER CORE FILLING).
(1) Carefully slide the heater core into the rear
HVAC housing.
(2) Using hand pressure, press firmly and evenly
on the heater core end plate until the four latch tabs
that secure the heater core in the rear HVAC housing
are fully engaged.
(3) Remove the plugs or tape from the heater core
fittings and both heater hoses.
(4) Reconnect the heater hoses to the rear heater
core (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - REAR/HEATER HOSE - INSTAL-
LATION).
(5) Install the screw that secures the front of the
rear HVAC housing to the right quarter inner panel.
Tighten the screw to 11 N´m (97 in. lbs.).
(6) Install the screw that secures the back of the
rear HVAC housing to the right D-pillar. Tighten the
screw to 11 N´m (97 in. lbs.).
(7) Install the rear heater distribution duct (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION - REAR/REAR HEATER DISTRIBUTION
DUCT - INSTALLATION).
(8) Install the right quarter trim panel and right
D-pillar trim panel (Refer to 23 - BODY/INTERIOR/
QUARTER TRIM PANEL - INSTALLATION).
(9) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
HEATER HOSES
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING).
(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 off of each end of the hose being
removed.
CAUTION:
DO NOT apply excessive pressure on heater tubes
or connections when removing heater hoses.
Excessive pressure may damage or deform the
tubes, causing an engine coolant leak.
(3) Disconnect the front underbody heater inlet
and return hose by carefully twisting the hoses back
and forth on the underbody tubes, while gently pull-
ing them away from the end of the tubes (Fig. 6).
(4) If necessary, carefully cut the hose ends and
peel the hoses off of the tubes.
NOTE:
Replacement of the heater hoses will be required if
the hose ends are cut for removal.
Fig. 6 Underbody Heater Hose Connections - Front
1 - SUCTION LINE EXTENSION
2 - LIQUID LINE EXTENSION
3 - RETAINER STRAP (3)
4 - HEATER TUBES
5 - UNDERBODY LINES
24 - 104 PLUMBING - REARRS
HEATER CORE (Continued)

INSTALLATION
(1) Install the front underbody heater inlet and
return hoses by carefully twisting the hoses back and
forth on the underbody tubes, while gently pushing
them onto the end of the tubes.
CAUTION:
DO NOT apply excessive pressure on heater tubes
or connections when removing heater hoses.
Excessive pressure may damage or deform the
tubes, causing an engine coolant leak.
(2) Using spring tension clamp pliers, compress
and slide the clamps that secure each end of the
heater hose over the tubes. Release the clamp when
it is over the tube.
(3) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
LIQUID LINE
REMOVAL
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: On models equipped with the optional rear
A/C system, the rear section of the front air condi-
tioner liquid line also includes a liquid line hose
and tube extension that connects the front liquid
line to the underbody liquid line for the rear A/C
system.
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/REFRIGERANT - STAN-
DARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the air cleaner housing from 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.
(5) Remove the A/C pressure transducer (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/A/C PRESSURE TRANSDUCER -
REMOVAL).(6) If equipped, remove the nut that secures the
A/C ground strap to the weld stud on the top of the
right front strut tower (Fig. 7).
(7) If equipped, remove the A/C ground strap eye-
let terminal connector from the weld stud.
(8) Remove the bolt that secures the liquid line
rear section fitting to the top of the receiver/drier.
(9) Disconnect the liquid line fitting from the
receiver/drier outlet port.
(10) Remove the O-ring seal from the liquid line
fitting and discard.
(11) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier outlet port.
(12) Remove the nut that secures the suction line
and liquid line fittings to the expansion valve.
(13) Disconnect the suction line and liquid line fit-
tings from the expansion valve.
(14) Remove the seals from the suction line and
liquid line fittings and discard.
(15) Install plugs in, or tape over the opened suc-
tion line and liquid line fittings and both expansion
valve ports.
(16) Raise and support the vehicle.
Fig. 7 Liquid Line
1 - A/C GROUND STRAP (IF EQUIPPED)
2 - NUT (IF EQUIPPED)
3 - WELD STUD (IF EQUIPPED)
4 - A/C PRESSURE TRANSDUCER
5 - WELD STUD (2)
6 - A/C EXPANSION VALVE
7 - A/C LIQUID LINE (REAR SECTION)
8 - LIQUID LINE EXTENSION (REAR A/C ONLY)
9 - NUT (2)
10 - RECEIVER/DRIER
11 - ROUTING CLIP
12 - A/C LIQUID LINE (FRONT SECTION)
RSPLUMBING - REAR24 - 105
HEATER HOSES (Continued)

WARNING: HIGH PRESSURES ARE PRODUCED IN
THE REFRIGERANT SYSTEM WHEN THE A/C COM-
PRESSOR IS OPERATING. HIGH TEMPERATURE
COOLANT IS PRESENT IN THE HEATER PLUMBING
WHEN THE ENGINE IS OPERATING. EXTREME
CARE MUST BE EXERCISED WHEN SERVICING
THE REAR HEATER AND A/C LINES TO PREVENT
POSSIBLE PERSONAL INJURY.
Any kinks or sharp bends in the rear heater-A/C
plumbing will reduce the capacity of the entire heat-
ing-A/C system. Kinks and sharp bends reduce the
system flow. High pressures are produced in the
refrigerant system when the A/C compressor is oper-
ating. High temperature coolant is present in the
heater plumbing when the engine is operating.
Extreme care must be exercised to make sure that
each of the connections is pressure-tight and leak
free.
REMOVAL
UNDERBODY HEATER TUBES
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING).
(1) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).(2) Raise and support vehicle.
(3) Disconnect the underbody heater tubes at the
rear of the vehicle by releasing the insert in the
underbody heater tube quick connect fittings and
carefully pulling downward on the heater tube fit-
tings (Fig. 14).
(4) Lower the underbody heater tubes and drain
any residual coolant from the tubes into a suitable
container.
Fig. 12 Rear Heater and A/C Lines ± Typical
1 - REAR HEATER TUBE CONNECTIONS2 - REAR A/C LINE CONNECTIONS
Fig. 13 Front Extension Lines to Underbody Lines ±
Typical
RSPLUMBING - REAR24 - 109
UNDERBODY LINES (Continued)

(5) Using spring tension clamp pliers, compress
and slide the clamps off of the rubber hoses at the
front of the underbody heater tubes (Fig. 15).
CAUTION:
DO NOT apply excessive pressure on heater tubes
or connections when removing heater hoses.
Excessive pressure may damage or deform the
tubes, causing an engine coolant leak.
(6) Disconnect the heater hoses by carefully twist-
ing the hoses back and forth on the rear heater
extension tubes, while gently pulling them away
from the end of the tubes.
(7) If necessary, carefully cut the hose ends and
peel the hoses off of the tubes.NOTE:
Replacement of the heater hoses will be required if
the hose ends are cut for removal.
(8) Remove the screws that secure the underbody
line retaining straps to the vehicle underbody.
(9) Remove the underbody heater tubes from the
retaining straps.
(10) Remove the underbody heater tubes from the
vehicle.
UNDERBODY REFRIGERANT LINES
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 CONDITION-
ING/PLUMBING - FRONT - STANDARD PROCE-
DURE - REFRIGERANT RECOVERY).
(2) Raise and support vehicle.
(3) Disconnect the exhaust system from the
exhaust hanger rubber isolators and position the
exhaust system out of the way (Refer to 11 -
EXHAUST SYSTEM - DESCRIPTION).
(4) Disconnect the underbody refrigerant lines
from the front liquid and suction line extension tubes
and remove and discard the O-ring seals. (Fig. 16).
Fig. 15 Underbody Connections
1 - SUCTION LINE EXTENSION TUBE
2 - LIQUID LINE EXTENSION TUBE
3 - RETAINING STRAP
4 - REAR HEATER EXTENSION TUBES
5 - UNDERBODY REFRIGERANT LINES
Fig. 16 Underbody A/C Line Front Connections ±
Typical
1 - SUCTION LINE EXTENSION TUBE
2 - LIQUID LINE EXTENSION TUBE
3 - RETAINING STRAP
4 - REAR HEATER EXTENSION TUBES
5 - UNDERBODY REFRIGERANT LINES
Fig. 14 Underbody Heater Tube Quick Connect
Fittings
1 - INSERT
2 - QUICK CONNECT FITTING
3 - COMPRESS INSERT FOR REMOVAL
24 - 110 PLUMBING - REARRS
UNDERBODY LINES (Continued)

CABIN HEATER
TABLE OF CONTENTS
page page
CABIN HEATER
DESCRIPTION........................113
OPERATION
MANUAL TEMPERATURE CONTROL
SYSTEM...........................113
AUTOMATIC TEMPERATURE CONTROL
SYSTEM...........................114
WARNING............................114
DIAGNOSIS AND TESTING
SUPPLEMENTAL CABIN HEATER........114
AIR INTAKE PIPE
REMOVAL............................115
INSTALLATION........................115
EXHAUST TUBE
REMOVAL............................116
INSTALLATION........................116
FUEL DOSING PUMP
DESCRIPTION........................117
OPERATION..........................117REMOVAL............................117
INSTALLATION........................117
FUEL LINE
STANDARD PROCEDURE
CLEANING..........................118
REMOVAL............................118
INSTALLATION........................118
HEATER HOSES
REMOVAL............................119
INSTALLATION........................119
HEATER PIPES
REMOVAL............................119
INSTALLATION........................120
HEATER UNIT
REMOVAL............................121
INSTALLATION........................122
HEATER WIRING
REMOVAL............................122
INSTALLATION........................122
CABIN HEATER
DESCRIPTION
Vehicles equipped with the diesel engine are also
equipped with a supplemental cabin heater. This
cabin heater is mounted under the vehicle and oper-
ates similar to an oil fired furnace. The heater burns
small amounts of fuel to provide additional heat to
the coolant. Coolant is routed from the engine, to the
supplemental cabin heater and then to the front
heater core. This provides additional heat to the pas-
senger compartment. The supplemental cabin heater
system is interfaced to the vehicles on-board com-
puter systems and DRBIIItdiagnostics.
The supplemental cabin heater has an electronic
control module that monitors the heat output of the
heater. The cabin heater operates at full load (5 kW),
half load or idle mode (no additional heat) depending
on engine coolant temperature.
When ambient temperatures are lower than 15É C
(60É F), the supplemental cabin heater automatically
operates once each ignition cycle for five minutes.
This assures a good fuel supply is always present for
the supplemental cabin heater.
OPERATION
MANUAL TEMPERATURE CONTROL SYSTEM
The supplemental cabin heater is activated via the
temperature slide control or knob on the A/C-heater
control when equipped with the manual temperature
control (MTC) system. If the slide control or knob is
moved to or above the upper set point the cabin
heater is activated. The cabin heater can operate in a
full or partial load range as well as an idle mode all
dependent on the engine coolant temperature. The
cabin heater will also turn off if the A/C-heater tem-
perature control is lowered to less than the lower set
point. The cabin heater can take up to three minutes
to completely shut down when either the heater tem-
perature is set below the lower set point or the vehi-
cle ignition is shut down.
NOTE: Do not apply a strong vacuum source such
as a garage ventilation system directly on the sup-
plemental cabin heater exhaust line. Too strong of a
vacuum can prevent the supplemental cabin heater
from starting. If required, place the vacuum source
at least 75 mm (3 in.) away from the exhaust line.
RSCABIN HEATER24 - 113

The supplemental cabin heater only operates when
the engine is running, the mileage exceeds 8 kilome-
ter (5 mph) and the fuel tank volume exceeds 1/8 of a
tank. The supplemental heater control module moni-
tors blower speed and combustion during its start-up.
The cabin heater should operate if the coolant tem-
perature is below 40É C (104É F).
AUTOMATIC TEMPERATURE CONTROL
SYSTEM
The automatic temperature control (ATC) system
will activate the supplemental cabin heater based on
engine coolant temperature and interior component
settings. The cabin heater can operate in a full or
partial load range as well as an idle mode all depen-
dent on the engine coolant temperature. The cabin
heater will also turn off if the A/C-heater tempera-
ture control is lowered to less than the lower set
point. The cabin heater can take up to three minutes
to completely shut down when either the heater tem-
perature is set below the lower set point or the vehi-
cle ignition is shut down.
NOTE: Do not apply a strong vacuum source such
as a garage ventilation system directly on the sup-
plemental cabin heater exhaust line. Too strong of a
vacuum can prevent the supplemental cabin heater
from starting. If required, place the vacuum source
at least 75 mm (3 in.) away from the exhaust line.
The supplemental cabin heater only operates when
the engine is running, the mileage exceeds 8 kilome-ter (5 mph) and the fuel tank volume exceeds 1/8 of a
tank. The supplemental heater control module moni-
tors blower speed and combustion during its start-up.
The cabin heater should operate if the coolant tem-
perature is below 40É C (104É F).
WARNING
WARNING: DO NOT OPERATE THE DIESEL SUP-
PLEMENTAL CABIN HEATER IN AN ENCLOSED
AREA SUCH AS A GARAGE THAT DOES NOT HAVE
EXHAUST VENTILATION FACILITIES. ALWAYS VENT
THE CABIN HEATER EXHAUST WHEN OPERATING
THE CABIN HEATER. ALLOW THE DIESEL SUPPLE-
MENTAL CABIN HEATER TO COOL BEFORE PER-
FORMING ANY SERVICE PROCEDURES TO THE
CABIN HEATER. VERIFY THAT ALL DIESEL SUP-
PLEMENTAL CABIN HEATER FUEL LINES ARE
SECURELY FASTENED TO THEIR RESPECTIVE
COMPONENTS BEFORE PERFORMING ANY SER-
VICE PROCEDURES TO THE CABIN HEATER. FAIL-
URE TO FOLLOW THESE INSTRUCTION MAY
RESULT IN PERSONAL INJURY OR DEATH.
DIAGNOSIS AND TESTING
SUPPLEMENTAL CABIN HEATER
Refer to the Symptoms Diagnosis table for basic
checks of the diesel fueled supplemental cabin heater.
SYMPTOMS DIAGNOSIS
Symptom Possible Causes
Smell of diesel fuel. Check cabin heater system integration in vehicle's fuel system. Check
fuel lines for leakage, kinks or obstructions. If OK, Inspect the inlet
muffler, drain as necessary. Re-test the cabin heater and re-inspect.
Inspect the exhaust tube and cabin heater for the presence of external
fuel. If presence of external fuel is observed on the heater unit or in the
exhaust tube or after draining and testing. Remove the cabin heater
from vehicle and repair or replace components as required.
Heater does not achieve full load
operation.Check cabin heater operation with DRBIIITscan tool and replace
components as required.
Continuous white smoke from heater
exhaust during combustion operation.Check cabin heater operation with DRBIIITscan tool and replace
components as required. White smoke is typical in extreme weather
conditions.
Heater can not be switched off. Check cabin heater operation with DRBIIITscan tool and replace
components as required.
Heater does not operate. Diagnosis cabin heater control module using the DRBIIITscan tool and
the procedures listed in Vehicle Performance under Cabin Heater
Diagnosis in Group 18.
24 - 114 CABIN HEATERRS
CABIN HEATER (Continued)

Symptom Possible Causes
Loss of coolant (Leakage) or heater
develops smoke during combustion
operation and exhaust has an
extremely sweet smell.Inspect coolant hoses for leakage, kinks or loose hose connection.
Inspect the exhaust tube assembly for continuous flow, if OK there is an
internal heater leak and cabin heater should be inspected and
components should be replaced as required.
Loss of fuel (dripping). Check cabin heater system integration in vehicles fuel system. Check
fuel line connection for leakage. If OK there is an internal leak and
cabin heater should be inspected and replaced as required.
AIR INTAKE PIPE
REMOVAL
NOTE: The air intake tube for the supplemental
cabin heater is part of an assembly that includes
the heater cooling intake and return pipes. If the
cabin heater air intake tube requires removal or
replacement the entire cabin heater assembly will
require removal or replacement.
(1) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(2) Remove clamps from the cabin heater tubes at
the lower heater port and the lower EGR connector
which are located under the hood.
(3) Remove the retaining clamp at the cabin
heater air intake muffler connection (Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/INLET MUFFLER - REMOVAL).
(4) Remove the clamp at the flexible tube to steel
tube connection (Fig. 1).(5) Remove the two retaining screws and remove
pipe assembly (Fig. 2).
INSTALLATION
(1) Install the air intake pipe assembly and install
the two retaining screws. Tighten the screws to 7
N´m (62 in. lbs.).
(2) Attach the steel tube to the flexible tube and
position and then tighten the retaining clamp
securely.
(3) Install the flexible tube to the cabin heater air
intake muffler and install and tighten the retaining
clamp securely.
(4) Install the cabin heater tubes to the lower
heater connection and the lower EGR cooler connec-
tion and tighten the retaining clamps.
(5) Lower the vehicle.
Fig. 1 Flexible Air Intake Line
1 - CABIN HEATER AND SPLASH SHIELD
2 - DOSING PUMP
3 - DOSING PUMP FUEL LINE
4 - FLEXIBLE AIR INTAKE LINE
5 - CLAMP
6 - STEEL INTAKE PIPE
Fig. 2 Cabin Heater 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
RSCABIN HEATER24 - 115
CABIN HEATER (Continued)

NOTE: Verify that there is more than 1/8 of a tank of
fuel in the vehicle's fuel tank before performing this
procedure. Add fuel, if necessary.
NOTE: Failure to prime the dosing pump after drain-
ing the supplemental cabin fuel line will prevent
cabin heater activation during the first attempt to
start the cabin heater. This will also set a diagnostic
trouble code (DTC) in the cabin heater control's
memory. Do not perform the Dosing Pump Priming
procedure if an attempt was made to start the cabin
heater without priming the dosing pump first. This
will put excess fuel in the cabin heater and cause
smoke to emit from the cabin heater exhaust pipe
when cabin heater activation occurs.
(7) Connect the DRBIIItscan tool to the diagnos-
tic link connector.
(8) Turn the ignition to the ON position.
NOTE: Do not activate the dosing pump prime more
than one time. This will put excess fuel in the sup-
plemental cabin heater and cause smoke to emit
from the cabin heater exhaust pipe when cabin
heater activation occurs.
NOTE: A clicking noise heard coming from the dos-
ing pump indicates that the pump is operational.
(9) With the DRBIIItscan tool in Cabin Heater,
select System Tests and Dosing Pump Prime. Allow
the dosing pump to run for the full 45 second cycle
time. When the 45 second cycle is complete, press
Page Back on the DRBIIItscan tool key pad to exit
the Dosing Pump Prime. The Dosing Pump Priming
procedure is now complete.
HEATER HOSES
REMOVAL
(1) Raise and support the vehicle. Take note of the
location of the flexible section of the cabin heater
exhaust tube.
(2) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
NOTE: Complete removal of the supplemental cabin
heater from vehicle is not required, lowering the
cabin heater allows easier access to coolant line
clamps.(3) Lower the supplemental cabin heater from the
vehicle (Refer to 24 - HEATING & AIR CONDITION-
ING/CABIN HEATER/HEATER UNIT - REMOVAL).
(4) Remove the clamps from both flexible coolant
line ends.
NOTE: It is recommended that both flexible cabin
heater coolant lines be replaced if either cabin
heater coolant line is damaged.
(5) Remove both coolant lines from vehicle.
INSTALLATION
(1) Install both flexible coolant lines to the supple-
mental cabin heater and install the clamps.
(2) Install the flexible coolant lines to the coolant
pipes and install the clamps.
(3) Install the supplemental cabin heater into the
vehicle (Refer to 24 - HEATING & AIR CONDITION-
ING/CABIN HEATER/HEATER UNIT - INSTALLA-
TION).
(4) Lower the vehicle.
(5) Fill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(6) Verify operation of the supplemental cabin
heater.
HEATER PIPES
REMOVAL
WARNING: ALLOW THE ENGINE COOLING SYSTEM
TO COOL COMPLETELY BEFORE REMOVING RADI-
ATOR CAP OR DRAINING THE ENGINE COOLING
SYSTEM. PERSONAL INJURY MAY RESULT IF THE
ENGINE COOLING SYSTEM IS OPENED WHILE
ENGINE COOLANT IS HOT AND UNDER PRES-
SURE.
NOTE: Steel heater lines from engine compartment
to the supplemental cabin heater are part of an
assembly that includes the air intake pipe. If the
cabin heater lines or air intake pipe require removal
or replacement the entire cabin heater assembly
will require removal or replacement.
(1) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(2) Remove clamps from both the EGR cooler and
the lower heater port. Separate hoses from the mat-
ing plumbing port (Fig. 6).
RSCABIN HEATER24 - 119
FUEL LINE (Continued)

(7) Connect the heater lines to the heater hoses at
the heater core and EGR port. Position spring clamps
onto the hoses.
(8) Fill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
HEATER UNIT
REMOVAL
WARNING: DO NOT OPERATE THE DIESEL SUP-
PLEMENTAL CABIN HEATER IN AN ENCLOSED
AREA SUCH AS A GARAGE THAT DOES NOT HAVE
EXHAUST VENTILATION FACILITIES. ALWAYS VENT
THE CABIN HEATER EXHAUST WHEN OPERATING
THE CABIN HEATER. ALLOW THE DIESEL SUPPLE-
MENTAL CABIN HEATER TO COOL BEFORE PER-
FORMING ANY SERVICE PROCEDURES TO THE
CABIN HEATER. VERIFY THAT ALL DIESEL SUP-
PLEMENTAL CABIN HEATER FUEL LINES ARE
SECURELY FASTENED TO THEIR RESPECTIVE
COMPONENTS BEFORE PERFORMING ANY SER-
VICE PROCEDURES TO THE CABIN HEATER. FAIL-
URE TO FOLLOW THESE INSTRUCTION MAY
RESULT IN PERSONAL INJURY OR DEATH.(1) Raise and support the vehicle. Take note of the
location of the flexible section of the cabin heater
exhaust tube.
(2) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(3) Carefully open one hose to the underbody tube
assembly and drain the remaining coolant. A salvage
hose is a good idea to control the residual coolant, as
flow will occur from both the cabin heater and the
hose and tube assemblies.
(4) Remove the second hose from the underbody
hose and tube assembly.
(5) Loosen the hose and tube assembly from the
toe-board crossmember at two locations.
(6) Disconnect the electrical connector from the
body harness near the toe-board crossmember and
rail.
(7) Remove the wiring harness from the toe-board
crossmember (Refer to 24 - HEATING & AIR CON-
DITIONING/CABIN HEATER/HEATER UNIT -
REMOVAL).
(8) Open the fuel filler cap. Disconnect the rubber
fuel hose between the body tube assembly and the
fuel pump nipple at the body tube joint. A minimal
amount of fuel may flow from the open port.
NOTE: Utilize an approved fuel storage container to
catch any residual fuel.
(9) Loosen the two fasteners at the rail. Take care
to notice that the exhaust tube bracket tab is on top
of the heater bracket and that there are two spacer
washers installed between the rubber grommets.
(10) Remove the flexible section of the cabin
heater exhaust tube from the exhaust tube by loos-
ening the clamp. Remove the hose from the exhaust
tube. Removal of the rail tube assembly may aid in
this service operation (Refer to 24 - HEATING & AIR
CONDITIONING/CABIN HEATER/EXHAUST TUBE
- REMOVAL).
(11) Remove seat hex nut at the heater mounting
flange to crossmember.
(12) Loosen the remaining fasteners which mount
the exhaust tube assembly to the vehicle.
(a) Install a suitable support device under the
cabin heater and secure the cabin heater to the
support.
(13) Loosen the remaining three fasteners to the
crossmembers.
(14) Remove the loosened fasteners that support
the cabin heater while supporting the weight of the
heater.
(15) Swing the cabin heater mounting bracket
from between the exhaust bracket and rail mounting
location. Drain any residual coolant from the cabin
heater.
Fig. 7 Cabin Heater 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
RSCABIN HEATER24 - 121
HEATER PIPES (Continued)

EMISSIONS CONTROL
TABLE OF CONTENTS
page page
EMISSIONS CONTROL
DESCRIPTION
VEHICLE EMISSION CONTROL
INFORMATION LABEL...................1
TRIP DEFINITION......................1
DESCRIPTION - MONITORED COMPONENT . 1
NON-MONITORED CIRCUITS.............5
DESCRIPTION - MONITORED SYSTEMS....6HIGH AND LOW LIMITS.................9
OPERATION
SYSTEM.............................9
DRB IIITSTATE DISPLAY TEST MODE.....10
EVAPORATIVE EMISSIONS................11
EXHAUST GAS RECIRCULATION...........22
ON-BOARD DIAGNOSTICS................25
EMISSIONS CONTROL
DESCRIPTION
VEHICLE EMISSION CONTROL INFORMATION
LABEL
All models have a Vehicle Emission Control Infor-
mation (VECI) Label. Chrysler permanently attaches
the label in the engine compartment. It cannot be
removed without defacing information and destroying
the label.
The label contains the vehicle's emission specifica-
tions and vacuum hose routings. All hoses must be
connected and routed according to the label.
TRIP DEFINITION
A ªTripº means vehicle operation (following an
engine-off period) of duration and driving mode such
that all components and systems are monitored at
least once by the diagnostic system. The monitors
must successfully pass before the PCM can verify
that a previously malfunctioning component is meet-
ing the normal operating conditions of that compo-
nent. For misfire or fuel system malfunction, the
MIL may be extinguished if the fault does not recur
when monitored during three subsequent sequential
driving cycles in which conditions are similar to
those under which the malfunction was first deter-
mined.
Anytime the MIL is illuminated, a DTC is stored.
The DTC can self erase only after the MIL has been
extinguished. Once the MIL is extinguished, the
PCM must pass the diagnostic test for the most
recent DTC for 40 warm-up cycles (80 warm-up
cycles for the Fuel System Monitor and the Misfire
Monitor). A warm-up cycle can best be described by
the following:
²The engine must be running²A rise of 40ÉF in engine temperature must occur
from the time when the engine was started
²Engine coolant temperature must crossover
160ÉF
²A ªdriving cycleº that consists of engine start up
and engine shut off.
Once the above conditions occur, the PCM is con-
sidered to have passed a warm-up cycle. Due to the
conditions required to extinguish the MIL and erase
the DTC, it is most important that after a repair has
been made, all DTC's be erased and the repair veri-
fied by running 1±good trip.
DESCRIPTION - MONITORED COMPONENT
There are several components that will affect vehi-
cle emissions if they malfunction. If one of these com-
ponents malfunctions the Malfunction Indicator
Lamp (Check Engine) will illuminate.
Some of the component monitors are checking for
proper operation of the part. Electrically operated
components now have input (rationality) and output
(functionality) checks as well as continuity tests
(opens/shorts). Previously, a component like the
Throttle Position sensor (TPS) was checked by the
PCM for an open or shorted circuit. If one of these
conditions occurred, a DTC was set. Now there is a
check to ensure that the component is working. This
is done by watching for a TPS indication of a greater
or lesser throttle opening than MAP and engine rpm
indicate. In the case of the TPS, if engine vacuum is
high and engine rpm is 1600 or greater and the TPS
indicates a large throttle opening, a DTC will be set.
The same applies to low vacuum and 1600 rpm.
Any component that has an associated limp in will
set a fault after 1 trip with the malfunction present.
Refer to the Diagnostic Trouble Codes Description
Charts in this section and the appropriate Power-
train Diagnostic Procedure Manual for diagnostic
procedures.
RSEMISSIONS CONTROL25-1