
(10) Pinch off rubber heater line hoses at front of
vehicle.
(11) Loosen hose clamps at front of heater lines
and allow them to hang from vehicle.
(12) Remove rear A/C lines from vehicle.
(13) Remove nylon wedge holding lines into rear
block (Fig. 14).INSTALLATION - REAR HEATER LINES
(1) Install line into underbody straps.
(2) Install line into front hose and install hose
clamp.
(3) Connect quick fitting at rear of line.
(4) Lower vehicle.
(5) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
INSTALLATION - REAR AIR CONDITIONING
LINES
(1) Before installation, replace all O-rings and gas-
kets. Coat all sealing surfaces with approved wax-
free refrigerant oil.
(2) Install A/C line into rear block with nylon
wedge.
(3) Install A/C lines into five underbody brackets.
(4) Connect forward compression fittings.
(5) Install bolt at sealing block to rear A/C hous-
ing.
(6) Install ABS harness into clips.
(7) Install heater hoses into underbody brackets.
(8) Install lines into front hoses and install hose
clamps.
(9) Lower vehicle.
(10) Evacuate and recharge system.
(11) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
Fig. 14 UNDERBODY LINE WEDGES
1 - O-RING
2 - DISCHARGE LINE
3 - NYLON WEDGE
4 - SEALING BLOCK
5 - VISE
6 - SUCTION LINE
RSPLUMBING - REAR24 - 107
UNDERBODY LINES (Continued)

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

INSTALLATION
(1) Install both flexible coolant lines to the heater
unit and install clamps.
(2) Install flexible coolant lines to the coolant pipes
and install clamps.
(3) Install heater unit into vehicle(Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/HEATER UNIT - INSTALLATION).
(4) Lower vehicle.
(5) Refill cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(6) Verify operation of heater unit.
HEATER PIPES - DIESEL
SUPPLEMENTAL HEATER
REMOVAL
CAUTION: Allow cooling system to cool completely
before removing radiator cap or draining cooling
system. Injury could result is system is opened
while system coolant is hot and under pressure.
NOTE: Steel heater lines from engine compartment
to heater unit are part of an assembly that includes
the air intake pipe. If the heater lines or air intake
pipe require removal or replacement the entire
assembly must be removed or replaced.
(1) Open hood.
(2) Drain the cooling system(Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) Remove clamps from both the EGR cooler and
the lower heater port. Separate hoses from the mat-
ing plumbing port. (Fig. 1).
(4) Remove retaining nut from heater line under
hood bracket.(5) Elevate vehicle on a lift.
NOTE: When supporting vehicle care should be
taken not to damage the heater exhaust tube.
(6) Remove clamps from heater lines to the rubber
connection nearest the tubes. Separate the hoses
from the tube assembly leaving the rubber hose
attached to the supplemental heater.
(7) Remove heater unit intake pipe from heater-
(Refer to 24 - HEATING & AIR CONDITIONING/
CABIN HEATER/INLET HOSE - REMOVAL) (Fig.
2).
(8) Remove heater pipe assembly retaining screws
and remove assembly from vehicle.
INSTALLATION
(1) With vehicle on a lift position the heater pipe
assembly and install the retaining screws.
(2) Install the heater unit intake pipe to the
heater unit(Refer to 24 - HEATING & AIR CONDI-
TIONING/CABIN HEATER/INLET HOSE - INSTAL-
LATION).
(3) Connect heater hoses to the heater unit and
tighten the clamps.
(4) Install heater unit intake pipe to heater uni-
t(Refer to 24 - HEATING & AIR CONDITIONING/
CABIN HEATER/INLET HOSE - INSTALLATION).
(5) Lower vehicle on lift.
(6) Install retaining nut to heater line under hood
bracket and tighten.
(7) Connect heater lines to heater hoses at heater
core and EGR port. Position spring clamps onto the
installed hoses.
(8) Refill cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(9) Close hood.
24a - 2 HEATING & AIR CONDITIONINGRG
HEATER HOSES - DIESEL SUPPLEMENTAL HEATER (Continued)

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)

(9) Tighten the hose and tube assembly to the toe-
board cross member at two locations.
(10) Install the second hose to the underbody hose
and tube assembly.
(11) Connect the rubber fuel hose between the
body tube assembly and the fuel pump nipple at the
body tube joint. Close the fuel fill cap.
(12) Remove the heater unit support device from
under the vehicle.
(13) Lower vehicle from lift.
(14) Refill cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(15) Verify function of the cabin heater.
SUPPLEMENTAL DIESEL
HEATER WIRING
REMOVAL
(1) Elevate vehicle on a lift taking note of the
exhaust tube flexible section.
(2) Unplug connector from vehicle wiring harness
to cabin heater harness.
(3) Unplug connector from cabin heater harness to
dosing pump connector.
(4) Unplug two connectors from cabin heater har-
ness to cabin heater controller connectors.
(5) Remove two wiring harness connectors from
underbody.
(6) Remove two wiring harness connectors from
cabin heater shield.
(7) Carefully route the cabin heater harness to the
left side between the cabin heater unit and the cabin
heater shield.
INSTALLATION
(1) Carefully route the cabin heater harness from
the left side of the cabin heater between the cabin
heater unit and the cabin heater shield.
(2) Install the two wiring harness retaining con-
nectors to the cabin heater shield.
(3) Route the wiring harness along the underside
of the vehicle and install the two wiring harness
retaining connectors.
(4) Plug the two connectors from the cabin heater
harness to the cabin heater controller.
(5) Plug the connector to the cabin heater harness
to the dosing pump connector.
(6) Plug the connector from the vehicle wiring har-
ness to the cabin heater harness.
(7) Lower the vehicle.
(8) Verify function of the cabin heater.
AIR INTAKE PIPE
REMOVAL
NOTE: Heater air intake tube is part of an assembly
that includes the heater cooling intake and return
pipes. If heater air intake tube requires removal or
replacement the entire assembly will require remov-
al/replacement.
(1) Drain cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(2) Remove clamps from the 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 heater air
intake muffler connection(Refer to 24 - HEATING &
AIR CONDITIONING/CABIN HEATER/INLET
MUFFLER - REMOVAL).
(4) Remove the clamp at the flexible tube to steel
tube connection (Fig. 7).
(5) Remove the two retaining screws and remove
pipe assembly (Fig. 8).
Fig. 7 FLEXIBLE AIR INTAKE LINE
1 - HEATER UNIT AND SPLASH SHIELD
2 - DOSING PUMP
3 - DOSING PUMP FUEL LINE
4 - FLEXIBLE INTAKE LINE
5 - CLAMP
6 - STEEL INTAKE PIPE
RGHEATING & AIR CONDITIONING24a-11
HEATER UNIT (Continued)

INSTALLATION
(1) Install the air intake pipe assembly and install
the two retaining screws. Tighten the screws to 7 Nm
( 5 ft. lbs.).
(2) Attach the steel tube to the flexible tube and
position and then tighten the retaining clamp.
(3) Install the flexible tube to the heater air intake
muffler and install and tighten the retaining clamp.
(4) Install the heater tubes to the lower heater
connection and the lower EGR cooler connection and
tighten the retaining clamps.
(5) Lower the vehicle.
(6) Refill the cooling system(Refer to 7 - COOLING
- STANDARD PROCEDURE).
(7) Verify function of the heater unit.
Fig. 8 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 - 12 HEATING & AIR CONDITIONINGRG
AIR INTAKE PIPE (Continued)

OPERATION
The engines use Exhaust Gas Recirculation (EGR)
systems. The EGR system reduces oxides of nitrogen
(NOx) in engine exhaust and helps prevent detona-
tion (engine knock). Under normal operating condi-tions, engine cylinder temperature can reach more
than 3000ÉF. Formation of NOx increases proportion-
ally with combustion temperature. To reduce the
emission of these oxides, the cylinder temperature
must be lowered. The system allows a predetermined
amount of hot exhaust gas to recirculate and dilute
the incoming air/fuel mixture. The diluted air/fuel
mixture reduces peak flame temperature during com-
bustion.
REMOVAL
(1) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(2) Remove front wiper unit (Refer to 8 - ELEC-
TRICAL/WIPERS/WASHERS/WIPER MODULE -
REMOVAL).
(3) Disconnect EGR valve vacuum line.
(4) Remove EGR cooler to EGR valve retaining
bolts (Fig. 1).
(5) Remove EGR valve retaining nuts (Fig. 1) and
EGR valve.
INSTALLATION
(1) Clean gasket mating surfaces.
(2) Install EGR valve (Fig. 1). Torque nuts to
32.4N´m.
(3) Connect EGR cooler to EGR valve (Fig. 1).
Torque bolts to 32.4N´m
(4) Install front wiper unit (Refer to 8 - ELECTRI-
CAL/WIPERS/WASHERS/WIPER MODULE -
INSTALLATION).
(5) Install engine cover (Refer to 9 - ENGINE -
INSTALLATION) .
VALVE COOLER
DESCRIPTION
The EGR valve on this engine uses a cooler to cool
the exhaust gases before the returned to the intake
manifold (Fig. 2). The EGR cooler attaches to the
EGR valve and is cooled with engine coolant.
REMOVAL
(1) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(2) Partially drain cooling system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE).
(3) Remove front wiper unit (Refer to 8 - ELEC-
TRICAL/WIPERS/WASHERS/WIPER MODULE -
REMOVAL) .
(4) Disconnect coolant supply and return lines at
EGR cooler (Fig. 2).
(5) Remove EGR cooler to exhaust manifold retain-
ing bolt (Fig. 2).
Fig. 1 EGR COMPONENTS
1 - HOSE CLAMP
2 - COOLANT HOSE
3 - HOSE CLAMP
4 - EGR VALVE RETAINING NUT
5 - E G R VA LV E
6 - COOLANT HOSE
7 - EGR VALVE GASKET
8 - EGR VALVE RETAINING STUDS
9 - EGR COOLER RETAINING BOLT
10 - HOSE CLAMP
11 - HOSE CLAMP
12 - EGR COOLER
13 - EGR COOLER TO EGR VALVE RETAINING BOLT
14 - TURBOCHARGER BRACKET
15 - TURBOCHARGER BRACKET RETAINING BOLT
16 - TURBOCHARGER DOWNPIPE
17 - TURBOCHARGER DOWNPIPE RETAINING NUT
18 - DOWNPIPE GASKET
19 - DOWNPIPE STUD
25a - 4 EXHAUST GAS RECIRCULATIONRG
VALVE (Continued)

(6) Remove EGR cooler to EGR valve retaining
bolts (Fig. 2) and remove cooler.
INSTALLATION
(1) Clean gasket sealing surfaces.
(2) Connect EGR valve cooler and new gasket to
EGR valve (Fig. 2). Torque bolts to 32.4N´m.
(3) Install EGR valve cooler to exhaust manifold
attaching bolt (Fig. 2). Torque bolt to 32.4N´m.
(4) Connect EGR cooler coolant supply and return
hoses to cooler (Fig. 2).
(5) Install front wiper unit (Refer to 8 - ELECTRI-
CAL/WIPERS/WASHERS/WIPER MODULE -
INSTALLATION).
(6) Refill cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(7) Install engine cover (Refer to 9 - ENGINE -
INSTALLATION) .
Fig. 2 EGR COMPONENTS
1 - HOSE CLAMP
2 - COOLANT HOSE
3 - HOSE CLAMP
4 - EGR VALVE RETAINING NUT
5 - E G R VA LV E
6 - COOLANT HOSE
7 - EGR VALVE GASKET
8 - EGR VALVE RETAINING STUDS
9 - EGR COOLER RETAINING BOLT
10 - HOSE CLAMP
11 - HOSE CLAMP
12 - EGR COOLER
13 - EGR COOLER TO EGR VALVE RETAINING BOLT
14 - TURBOCHARGER BRACKET
15 - TURBOCHARGER BRACKET RETAINING BOLT
16 - TURBOCHARGER DOWNPIPE
17 - TURBOCHARGER DOWNPIPE RETAINING NUT
18 - DOWNPIPE GASKET
19 - DOWNPIPE STUD
RGEXHAUST GAS RECIRCULATION25a-5
VALVE COOLER (Continued)