HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
PLUMBING - FRONT
WARNING...............................1
HEATER HOSES - DIESEL SUPPLEMENTAL
HEATER
REMOVAL...............................1
INSTALLATION............................2
HEATER PIPES - DIESEL SUPPLEMENTAL
HEATER
REMOVAL...............................2
INSTALLATION............................2
REFRIGERANT
DIAGNOSIS AND TESTING..................4
DIAGNOSIS & TESTING - REFRIGERANT
CHARGE LEVEL 2.5L DIESEL...............4
DIESEL SUPPLEMENTAL HEATER - DCHA
DESCRIPTION............................5
OPERATION.............................6
DIAGNOSIS AND TESTING..................6
DIESEL SUPPLEMENTAL HEATER - DCHA....6
EXHAUST TUBE
REMOVAL...............................6INSTALLATION............................7
FUEL DOSING PUMP
DESCRIPTION............................7
OPERATION.............................7
REMOVAL...............................7
INSTALLATION............................8
FUEL LINE
STANDARD PROCEDURE...................8
CLEANING.............................8
REMOVAL...............................8
INSTALLATION............................9
HEATER UNIT
REMOVAL..............................10
INSTALLATION...........................10
SUPPLEMENTAL DIESEL HEATER WIRING
REMOVAL..............................11
INSTALLATION...........................11
AIR INTAKE PIPE
REMOVAL..............................11
INSTALLATION...........................12
PLUMBING - FRONT
WARNING
WARNING:: DO NOT OPERATE DCHA IN AN
ENCLOSED AREA SUCH AS A GARAGE THAT
DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA'S EXHAUST WHEN
OPERATING THE DCHA. FAILURE TO FOLLOW
THESE INSTRUCTION MAY RESULT IN PERSONAL
INJURY OR DEATH.
ALLOW THE DCHA ASSEMBLY TO COOL BEFORE
PERFORMING A COMPONENT INSPECTION/RE-
PAIR/REPLACEMENT. FAILURE TO FOLLOW THESE
INSTRUCTIONS MY RESULT IN PERSONAL INJURY.
VERIFY THAT ALL DCHA FUEL LINES ARE
SECURELY FASTENED TO THEIR RESPECTIVE
COMPONENTS BEFORE THIS PROCEDURE.
HEATER HOSES - DIESEL
SUPPLEMENTAL HEATER
REMOVAL
(1) Elevate vehicle on a lift taking note of the
exhaust tube flexible section.
(2) Drain cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Lower heater unit from vehicle(Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/HEATER UNIT - REMOVAL).
NOTE: Complete removal of cabin heater from vehi-
cle is not required, lowering unit allows easier
access to coolant line clamps.
(4) Remove clamps from both flexible coolant line
ends.
(5) Remove both lines from vehicle.
NOTE: If either line is damaged it is recommended
that both flexible lines be replaced.
RGHEATING & AIR CONDITIONING24a-1
ProCarManuals.com
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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OPERATION
The supplemental heater unit is activated via the
temperature slide control or knob on the vehicle HVAC
control unit. If the control slide or knob is moved to or
above the upper set point the heater is activated. The
unit can operate in a full or partial load range as well
as an idle mode all dependent on the engine coolanttemperature. The heater unit will also turn off if the
HVAC temperature control is lowered to less than the
lower set point. The heater unit can take up to three
minutes to completely shut down when either the
heater temperature is set below the lower set point or
the vehicle ignition is shut down.
DIAGNOSIS AND TESTING - DIESEL SUPPLEMENTAL HEATER - DCHA
The following table lists possible fault symptoms of
diesel fueled heaters.
SYMPTOM POSSIBLE CAUSES
Smell of diesel fuel Check 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 unit and re-inspect. Inspect the
exhaust tube and heater unit for the presence of external fuel. If a
volume is observed on the unit or in the exhaust tube or after draining
and testing. Remove heater unit from vehicle and repair or replace
components as required.
Heater does not achieve full load
operation.Check heater operation with DRB-III and replace components as
required.
Continuous white smoke from heater
exhaust during combustion operation.Check heater operation with DRB-III and replace components as
required. White smoke is typical in extreme weather conditions.
Heater can not be switched off. Check heater operation with DRB-III and replace components as
required.
Heater does not operate. Diagnosis cabin heater ECU using the DRB-III and the procedures
listed in Vehicle Performance under Cabin Heater Diagnosis in Group
18.
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 unit should be inspected and components
should be replaced as required.
Loss of fuel (dripping). Check heater system integration in vehicles fuel system. Check fuel
line connection for leakage. If OK there is an internal leak and unit
should be inspected and replaced as required.
EXHAUST TUBE
REMOVAL
WARNING: THERE IS A POTENTIAL DANGER OF
SKIN BURNS AS THE HEATER AND ITS COMPO-
NENTS MAY BE VERY HOT. MAKE SURE THE
HEATER IS ALLOWED TO COOL DOWN BEFORE
ANY SERVICE WORK IS ATTEMPTED.
WARNING: THERE IS A POTENTIAL DANGER OF
SKIN BURNS AS THE EXHAUST SYSTEM MAY BE
VERY HOT. MAKE SURE THE EXHAUST SYSTEM ISALLOWED TO COOL DOWN BEFORE ANY SERVICE
WORK IS ATTEMPTED ON THE CABIN HEATER.
(1) Elevate vehicle on a lift taking note of the
exhaust tube flexible section.
(2) Remove the exhaust clamp at the flexible pipe
and steel pipe connection (Fig. 4).
(3) Remove the clamp at the flexible pipe connec-
tion and the heater unit housing (if required).
(4) Remove the three screws holding the exhaust
pipe to the body.
(5) Remove the steel exhaust pipe from the vehi-
cle.
(6) Remove the flexible exhaust pipe from the
vehicle (if required).
24a - 6 HEATING & AIR CONDITIONINGRG
DIESEL SUPPLEMENTAL HEATER - DCHA (Continued)
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INSTALLATION
WARNING: DO NOT OPERATE THE DCHA IN AN
ENCLOSED AREA SUCH AS A GARAGE THAT
DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA'S EXHAUST WHEN
OPERATING THE DCHA. FAILURE TO FOLLOW
THESE INSTRUCTIONS MAY RESULT IN PERSONAL
INJURY OR DEATH.
WARNING: ALLOW THE DCHA ASSEMBLY TO
COOL BEFORE PERFORMING A COMPONENT
INSPECTION/REPAIR/REPLACEMENT. FAILURE TO
FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY.
WARNING: VERIFY THAT ALL DCHA FUEL LINES
ARE SECURELY FASTENED TO THEIR RESPECTIVE
COMPONENTS BEFORE PERFORMING THIS PRO-
CEDURE.
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.(1) Install heater fuel supply line to vehicle and
install in fuel line retainers
(2) Install fuel line connection at fuel tank and
tighten connection.
(3) Install fuel line at Dosing Pump and tighten
connection.
(4) Lower vehicle from lift.
NOTE: Failure to prime the Dosing Pump after
draining the DCHA fuel line will prevent DCHA
heater activation during the first attempt to start the
heater. This will also set a Diagnostic Trouble Code
(DCT) in the DCHA Control's memory. do not per-
form the Dosing Pump Priming procedure if an
attempt was made to start the DCHA without prim-
ing the Dosing Pump first. This will put excess fuel
in the DCHA Heater Module and cause smoke to
emit from the DCHA exhaust pipe when heater acti-
vation occurs.
(5) Connect the DRBIIItto the Diagnostic Link
Connector.
(6) Turn the ignition to the on position.
Fig. 6 Dosing Pump Fuel Line
1 - Fuel Line
2 - Retaining Clamps3 - Dosing Pump
4 - Heater Unit Air Intake Pipe
RGHEATING & AIR CONDITIONING24a-9
FUEL LINE (Continued)
ProCarManuals.com
NOTE:Do not activate the Dosing Pump Prime more
than one time. This will put excess fuel in the DCHA
Heater Module an cause smoke to emit from the
DCHA exhaust pipe when heater activation occurs.
NOTE: A clicking noise heard coming from the Dos-
ing Pump indicates that the pump is operational.
(7)
With the DRBIIItin Cabin Heater, select Sys-
tem 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 DRBIIItkey pad to exit the Dosing Pump Prime.
The Dosing Pump priming procedure is now complete.
HEATER UNIT
REMOVAL
WARNING: ALLOW THE DCHA TO COOL BEFORE
PERFORMING A COMPONENT INSPECTION/REPAIR
OR REPLACEMENT. FAILURE TO FOLLOW THESE
INSTRUCTIONS MAY RESULT IN PERSONAL
INJURY.
WARNING: ALLOW THE EXHAUST SYSTEM TO
COOL BEFORE PERFORMING A COMPONENT
INSPECTION/REPAIR OR REPLACEMENT. FAILURE
TO FOLLOW THESE INSTRUCTION MAY RESULT IN
PERSONAL INJURY.
(1) Elevate the vehicle on a hoist/lift taking note of
heater exhaust tube flexible section.
(2) Drain 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 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 cross member at two locations.
(6) Disconnect the electrical connector from the
body harness near the toe board cross member and
rail.
(7) Remove the wiring harness from the toe board
cross member(Refer to 24 - HEATING & AIR CON-
DITIONING/CABIN HEATER/HEATER UNIT -
REMOVAL).
(8) Open the fuel fill 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 M8 fasteners at the rail. Take
care to notice that the exhaust tube bracket tab is on
top of the heater bracket.
(10) Remove the heater exhaust tube flex section
from the exhaust tube by loosening the M6 bolt of
the clamp assembly. 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 cross member.
(12) Loosen the remaining M6 and M8 fasteners
which mount the exhaust tube assembly to the vehi-
cle.
(a) Install a suitable cabin heater support device
under the cabin heater and secure the cabin heater
to the device.
(13) Loosen the remaining three M6 fasteners to
the cross members.
(14) Remove the loosened fasteners that support
the heater while supporting the weight of the heater.
(15) Swing the unit mounting bracket from
between the exhaust bracket and rail mounting loca-
tion. Drain any residual coolant from the heater unit.
(16) Lower the cabin heater and remove from the
supporting device and place on a suitable work area.
INSTALLATION
(1) Install the unit mounting bracket between the
exhaust bracket and the rail mounting location.
(2) Install the fasteners that support the heater
while supporting the weight of the heater.
(3) Install the three M6 fasteners to the cross
members. Tighten the M6 fasteners to 7 Nm (5 ft.
lbs.).
(4) Tighten the remaining M6 fasteners to 7 Nm (5
ft. lbs.) and the M8 fasteners to 23 Nm (17 ft. lbs.)
which mount the exhaust tube assembly to the vehi-
cle.
(5) Install the seat hex nut at the heater mounting
flange to the cross members. Tighten to 60 Nm (44 ft.
lbs.)
(6) Install the heater exhaust tube flex section to
the exhaust tube by tightening the M6 bolt of the
clamp assembly. Install the hose to the exhaust tube.
(7) Tighten the two M8 fasteners at the rail to 23
Nm (17 ft. lbs.). Taking care so that the exhaust tube
bracket tab is on the top of the heater bracket.
(8) Install the wiring harness(Refer to 24 - HEAT-
ING & AIR CONDITIONING/CABIN HEATER/
HEATER UNIT - INSTALLATION).
24a - 10 HEATING & AIR CONDITIONINGRG
FUEL LINE (Continued)
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PCV VALVE
DESCRIPTION
The PCV valve contains a spring loaded plunger.
The plunger meters the amount of crankcase vapors
routed into the combustion chamber based on intake
manifold vacuum.
OPERATION
When the engine is not operating or during an
engine backfire, the spring forces the plunger back
against the seat. This prevents vapors from flowing
through the valve (Fig. 8).
When the engine is at idle or cruising, high mani-
fold vacuum is present. At these times manifold vac-
uum is able to completely compress the spring and
pull the plunger to the top of the valve (Fig. 9). In
this position there is minimal vapor flow through the
valve.During periods of moderate intake manifold vac-
uum the plunger is only pulled part way back from
the inlet. This results in maximum vapor flow
through the valve (Fig. 10).
DIAGNOSIS AND TESTING - PCV SYSTEM
INSPECTION
WARNING: APPLY PARKING BRAKE AND/OR
BLOCK WHEELS BEFORE PERFORMING ANY TEST
OR ADJUSTMENT WITH THE ENGINE OPERATING.
(1) With engine idling, remove the hose from the
PCV valve. If the valve is not plugged, a hissing
noise will be heard as air passes through the valve. A
strong vacuum should also be felt when a finger is
placed over the valve inlet.
(2) Install hose on PCV valve. Remove the
make-up air hose from the air plenum at the rear of
the engine. Hold a piece of stiff paper (parts tag)
loosely over the end of the make-up air hose.
(3)
After allowing approximately one minute for
crankcase pressure to reduce, the paper should draw up
against the hose with noticeable force. If the engine
does not draw the paper against the grommet after
installing a new valve, replace the PCV valve hose.
(4)Turn the engine off. Remove the PCV valve from
intake manifold. The valve should rattle when shaken.
(5) Replace the PCV valve and retest the system if
it does not operate as described in the preceding
tests.Do not attempt to clean the old PCV valve.
If the valve rattles, apply a light coating of Loctitet
Pipe Sealant With Teflon to the threads. Thread the
PCV valve into the manifold plenum and tighten to 7
N´m (60 in. lbs.) torque.
Fig. 7 PCV VALVE 2.4L
1 - PCV Valve
Fig. 8 Engine Off or Engine Backfire No Vapor Flow
Fig. 9 High Intake Manifold Vacuum Minimal Vapor
Flow
Fig. 10 Moderate Intake Manifold Vacuum Maximum
Vapor Flow
RSEVAPORATIVE EMISSIONS25-17
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The Task Manager Screen shows both a Requested
MIL state and an Actual MIL state. When the MIL is
illuminated upon completion of a test for a third trip,
the Requested MIL state changes to OFF. However,
the MIL remains illuminated until the next key
cycle. (On some vehicles, the MIL will actually turn
OFF during the third key cycle) During the key cycle
for the third good trip, the Requested MIL state is
OFF, while the Actual MILL state is ON. After the
next key cycle, the MIL is not illuminated and both
MIL states read OFF.
Diagnostic Trouble Codes (DTCs)
With OBD II, different DTC faults have different
priorities according to regulations. As a result, the
priorities determine MIL illumination and DTC era-
sure. DTCs are entered according to individual prior-
ity. DTCs with a higher priority overwrite lower
priority DTCs.
Priorities
²Priority 0 ÐNon-emissions related trouble codes
²Priority 1 Ð One trip failure of a two trip fault
for non-fuel system and non-misfire.
²Priority 2 Ð One trip failure of a two trip fault
for fuel system (rich/lean) or misfire.
²Priority3ÐTwotrip failure for a non-fuel sys-
tem and non-misfire or matured one trip comprehen-
sive component fault.
²Priority4ÐTwotrip failure or matured fault
for fuel system (rich/lean) and misfire or one trip cat-
alyst damaging misfire.
Non-emissions related failures have no priority.
One trip failures of two trip faults have low priority.
Two trip failures or matured faults have higher pri-
ority. One and two trip failures of fuel system and
misfire monitor take precedence over non-fuel system
and non-misfire failures.
DTC Self Erasure
With one trip components or systems, the MIL is
illuminated upon test failure and DTCs are stored.
Two trip monitors are components requiring failure
in two consecutive trips for MIL illumination. Upon
failure of the first test, the Task Manager enters a
maturing code. If the component fails the test for a
second time the code matures and a DTC is set.
After three good trips the MIL is extinguished and
the Task Manager automatically switches the trip
counter to a warm-up cycle counter. DTCs are auto-
matically erased following 40 warm-up cycles if the
component does not fail again.
For misfire and fuel system monitors, the compo-
nent must pass the test under a Similar Conditions
Window in order to record a good trip. A Similar Con-
ditions Window is when engine RPM is within6375RPM and load is within610% of when the fault
occurred.
NOTE: It is important to understand that a compo-
nent does not have to fail under a similar window of
operation to mature. It must pass the test under a
Similar Conditions Window when it failed to record
a Good Trip for DTC erasure for misfire and fuel
system monitors.
DTCs can be erased anytime with a DRBIIIt.
Erasing the DTC with the DRBIIIterases all OBD II
information. The DRBIIItautomatically displays a
warning that erasing the DTC will also erase all
OBD II monitor data. This includes all counter infor-
mation for warm-up cycles, trips and Freeze Frame.
Trip Indicator
TheTripis essential for running monitors and
extinguishing the MIL. In OBD II terms, a trip is a
set of vehicle operating conditions that must be met
for a specific monitor to run. All trips begin with a
key cycle.
Good Trip
The Good Trip counters are as follows:
²Global Good Trip
²Fuel System Good Trip
²Misfire Good Trip
²Alternate Good Trip (appears as a Global Good
Trip on DRBIIIt)
²Comprehensive Components
²Major Monitor
²Warm-Up Cycles
Global Good Trip
To increment a Global Good Trip, the Oxygen sen-
sor and Catalyst efficiency monitors must have run
and passed.
Fuel System Good Trip
To count a good trip (three required) and turn off
the MIL, the following conditions must occur:
²Engine in closed loop
²Operating in Similar Conditions Window
²Short Term multiplied by Long Term less than
threshold
²Less than threshold for a predetermined time
If all of the previous criteria are met, the PCM will
count a good trip (three required) and turn off the
MIL.
Misfire Good Trip
If the following conditions are met the PCM will
count one good trip (three required) in order to turn
off the MIL:
²Operating in Similar Condition Window
²1000 engine revolutions with no misfire
Alternate Good Trip
Alternate Good Trips are used in place of Global
Good Trips for Comprehensive Components and
25 - 24 ON-BOARD DIAGNOSTICSRS
TASK MANAGER (Continued)
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