(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)
INSTALLATION
UNDERBODY HEATER TUBES
(1) Position the underbody heater tubes onto the
vehicle underbody.
(2) Install the underbody heater tubes into the
underbody line retaining straps.
(3) Install the bolts that secure the retaining
straps to the vehicle underbody. Tighten the screws
securely.
(4) Connect the rubber hoses at the front of the
underbody heater tubes to the rear heater extension
tubes.
(5) Using spring tension clamp pliers, compress
and slide the clamps that secure the heater hoses
over the extension tubes. Release the clamp when it
is correctly positioned over the tube.
(6) Connect the rear underbody heater tube quick
connections to the rear heater core extension tubes.
(7) Lower the vehicle.
(8) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
UNDERBODY REFRIGERANT LINES
(1) If removed, install the underbody refigerant
lines into the underbody refrigerant line sealing plate
and install the nylon wedges that secure the refrig-
erant lines to the sealing plate.
(2) Position the underbody refrigerant lines onto
the vehicle underbody.
(3) Install the underbody refrigerant lines into the
underbody line retaining straps.
(4) Install the bolts that secure the retaining
straps to the vehicle underbody. Tighten the screws
securely.(5) Remove the tape or plugs from the rear under-
body refrigerant line fittings and the rear evaporator
extension line ports.
(6) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them onto the underbody
refrigerant line fittings.
(7) Connect the underbody refrigerant lines to the
rear evaporator extension line tapping plate.
(8) Install the bolt or nut (depending on applica-
tion) that secures the underbody refrigerant line
sealing plate to the rear evaporator extension line
tapping plate. Tighten the bolt or nut to 23 N´m (17
ft. lbs.).
(9) Remove the tape or plugs from the front liquid
and suction line extension tubes and the underbody
refrigerant line fittings.
(10) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them onto the underbody
refrigerant line fittings.
(11) Connect the underbody refrigerant line fit-
tings to the front liquid and suction line extension
tubes. Tighten the fittings to 23 N´m (17 ft. lbs.).
(12) Position the exhaust system and install it to
the exhaust hanger rubber isolators (Refer to 11 -
EXHAUST SYSTEM - DESCRIPTION).
(13) Lower the vehicle.
(14) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT - STANDARD PROCEDURE - REFRIGER-
ANT SYSTEM EVACUATE).
(15) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT - STANDARD PROCEDURE - REFRIGER-
ANT SYSTEM CHARGE).
24 - 112 PLUMBING - REARRS
UNDERBODY LINES (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)
(6) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(7) Verify function of the cabin heater.
EXHAUST TUBE
REMOVAL
WARNING: THERE IS A POTENTIAL DANGER OF
SKIN BURNS AS THE SUPPLEMENTAL CABIN
HEATER AND ITS COMPONENTS MAY BE VERY
HOT. MAKE SURE THE CABIN HEATER IS
ALLOWED TO COOL DOWN BEFORE ANY SERVICE
WORK ON THE CABIN HEATER SYSTEM IS
ATTEMPTED.
(1) Raise and support the vehicle. Take note of the
location of the flexible section of the cabin heater
exhaust tube.
(2) Remove the exhaust clamp at the flexible pipe
and steel pipe connection (Fig. 3).
(3) Remove the clamp at the flexible pipe connec-
tion and the cabin heater 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).
INSTALLATION
(1) Install the flexible exhaust pipe to the cabin
heater. Tighten the mounting clamp securely.
(2) Position the steel exhaust pipe to the flexible
exhaust. Tighten the mounting clamp securely.
(3) Loosely install the three exhaust pipe screws
and adjust pipe placement as required. Tighten the
screws securely.
(4) Install the clamp that secures the steel exhaust
pipe to the flexible exhaust pipe. Tighten the clamp
securely.
(5) Check exhaust end placement of the exhaust
pipe and make any final adjustments.
(6) Lower the vehicle.
Fig. 3 Cabin Heater Exhaust System
1 - MOUNTING SCREWS (3)
2 - STEEL HEATER EXHAUST PIPE
3 - EXHAUST CLAMP (2)4 - FLEXIBLE HEATER EXHAUST PIPE
5 - CABIN HEATER AND SHIELD
6 - EXHAUST PIPE MOUNTING CLIPS (3) (IF EQUIPPED)
24 - 116 CABIN HEATERRS
AIR INTAKE PIPE (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)