2006 MERCEDES-BENZ SPRINTER ECU

CAUTION: Use only the specified O-rings as they
are made of a special material for the R-134a sys-
tem. The use of any other O-rings may allow the
connection to leak intermittently during vehicle
operation.
(4) Lubricate the male fitting and O-rings, and the
inside of the female fitting with clean R-134a refrig-
erant oil. Use only refrigerant oil of the type recom-
mended for the compressor in the vehicle.
(5) Fit the female half of the coupler fitting over
the male half of the fitting.
(6) Push together firmly on the two halves of the
coupler fitting until the garter spring in the cage on
the male half of the fitting snaps over the flanged
end on the female half of the fitting.
(7) Ensure that the spring-lock coupler is fully
engaged by trying to separate the two coupler halves.
This is done by pulling the refrigerant lines on either
side of the coupler away from each other.
(8) Reinstall the secondary retaining clip over the
spring-lock coupler cage.
(9) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(10) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
UNDERBODY LINES
REMOVAL
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
NOTE: The underbody refrigerant lines for the
optional rear A/C system are serviced in five sec-
tions. Two sections are connected the A/C compres-
sor. Two sections of the underbody suction line
(low-side) are connected together by a tapping
block with an O-ring seal. The underbody A/C dis-
charge line uses a spring-lock type refrigerant line
coupler with an O-ring seal.
DISCHARGE LINE
(1) Remove the cover from the rear A/C evaporator
housing (Refer to 24 - HEATING & AIR CONDI-TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - REMOVAL).
(2) Recover the refrigerant from the rear refriger-
ant system (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Raise and support the vehicle.
(4) Using the proper A/C line disconnect tool, dis-
connect the underbody discharge line spring-lock cou-
pler from the compressor section of the underbody
discharge line and remove and discard the O-ring
seal (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING/REFRIGERANT LINE COUPLER -
REMOVAL) (Fig. 39).
(5) Disconnect the underbody discharge line from
the rear A/C discharge line and remove and discard
the O-ring seal.
(6) Install plug in, or tape over all of the opened
discharge line fittings.
(7) Disengage the fuel lines from the retaining clip
located near the transmission and position the fuel
lines out of the way.
(8) Remove the screws and brackets that secure
the discharge line to the underneath of the vehicle.
(9) Support transmission with a suitable lifting
device and remove the rear transmission crossmem-
ber (Refer to 13 - FRAME & BUMPERS/FRAME/
REAR CROSSMEMBER-TRANSMISSION -
REMOVAL).
(10) Remove the underbody discharge line from
the vehicle. Push the discharge line forward and over
the transmission, then pull it rearward to remove.
(11) If necessary, remove the bolt that secures the
compressor section of the underbody discharge line to
the A/C compressor and remove and discard the
O-ring seal. Make sure to plug in, or tape over the
opened discharge line fitting and compressor port.
24 - 100 PLUMBINGVA

SUCTION LINE - FRONT SECTION
(1) Remove the cover from the rear A/C evaporator
housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - REMOVAL).
(2) Recover the refrigerant from the rear refriger-
ant system (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Raise and support the vehicle.
(4) Disconnect the connection of the front section
of the underbody suction line from the compressor
section of the underbody suction line and remove and
discard the O-ring seal (Fig. 40).
(5) Remove the bolt that secures the connection of
the front section of the underbody suction line to the
rear section of the underbody suction line.
(6) Disconnect the front section of the underbody
suction line from the rear section and remove and
discard the O-ring seal.
(7) Install plug in, or tape over all of the opened
suction line fittings.
(8) Remove the screws and brackets that secure
the front section of the underbody suction line to the
underneath of the vehicle and remove the front sec-
tion of the suction line.(9) If necessary, remove the bolt that secures the
compressor section of the underbody suction line to
the A/C compressor and remove and discard the
O-ring seal. Make sure to plug in, or tape over the
opened underbody suction line fitting and compressor
port.
Fig. 39 Underbody Discharge Line
1 - UNDERBODY DISCHARGE LINE
2 - FUEL LINES
3 - REAR A/C DISCHARGE
4 - REAR TRANSMISSION CROSSMEMBER5 - SCREW AND BRACKET (2)
6 - DISCHARGE LINE-COMPRESSOR SECTION
7 - RETAINING CLIP
VAPLUMBING 24 - 101

SUCTION LINE - REAR SECTION
(1) Remove the cover from the rear A/C evaporator
housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - REMOVAL).
(2) Recover the refrigerant from the rear refriger-
ant system (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Raise and support the vehicle.
(4) Remove the bolt that secures the connection of
the front section of the underbody suction line to the
rear section of the underbody suction line (Fig. 41).
(5) Disconnect the front section of the underbody
suction line from the rear section and remove and
discard the O-ring seal.
(6) Disconnect the rear section of the underbody
suction line from the rear A/C suction line and
remove and discard the O-ring seal.
(7) Install plug in, or tape over all of the opened
suction line fittings.
(8) Remove the screws and brackets that secure
the rear section of the underbody suction line to the
underneath of the vehicle and remove the rear sec-
tion of the suction line.INSTALLATION
DISCHARGE LINE
(1) If the compressor section of the underbody dis-
charge line was removed from the A/C compressor,
remove plugs or tape from the discharge line fitting,
lubricate a new rubber O-ring seal with clean refrig-
erant oil, install it onto the discharge line fitting and
install the bolt that secures the discharge line to the
compressor. Tighten the bolt to 21 N´m (15 ft. lbs.).
(2) Position the underbody discharge line to the
vehicle.
(3) Install the brackets and screws that secure the
underbody discharge line to the underneath of the
vehicle. Tighten the screws to 8 N´m (70 in. lbs.).
(4) Engage the fuel lines to the retaining clips
located near the transmission.
(5) Install the rear transmission crossmember
(Refer to 13 - FRAME & BUMPERS/FRAME/REAR
CROSSMEMBER-TRANSMISSION - INSTALLA-
TION).
(6) Remove the plugs or tape from the discharge
line fittings.
(7) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them onto the discharge
line fittings.
(8) Connect the underbody discharge line spring-
lock coupler to the compressor section of the dis-
charge line and install the secondary retaining clip
(if equipped) (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/REFRIGERANT LINE COU-
PLER - INSTALLATION).
Fig. 40 Underbody Suction Line - Front Section
1 - UNDERBODY SUCTION LINE-FRONT SECTION
2 - BOLT
3 - UNDERBODY SUCTION LINE-REAR SECTION
4 - SUCTION LINE-COMPRESSOR SECTION
5 - SCREW AND BRACKET (2)
Fig. 41 Underbody Suction Line - Rear Section
1 - REAR A/C DISCHARGE LINE
2 - UNDERBODY SUCTION LINE-REAR SECTION
3 - SCREW AND BRACKET (3)
4 - BOLT
5 - UNDERBODY SUCTION LINE-FRONT SECTION
24 - 102 PLUMBINGVA

(9) Connect the rear A/C discharge line to the
underbody discharge line. Tighten the nut to 35 N´m
(26 ft. lbs.).
(10) Lower the vehicle.
(11) Evacuate the rear refrigerant system (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(12) Charge the rear refrigerant system (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
(13) Install the cover onto the rear A/C evaporator
housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - INSTALLATION).
SUCTION LINE - FRONT SECTION
(1) If the compressor section of the underbody suc-
tion line was removed from the A/C compressor,
remove plugs or tape from the suction line fitting,
lubricate a new rubber O-ring seal with clean refrig-
erant oil, install it onto the suction line fitting and
install the bolt that secures the suction line to the
compressor. Tighten the bolt to 21 N´m (15 ft. lbs.).
(2) Position the front section of the underbody suc-
tion line to the vehicle.
(3) Install the brackets and screws that secure the
front section of the underbody suction line to the
underneath of the vehicle. Tighten the screws to 8
N´m (70 in. lbs.).
(4) Remove the plugs or tape from the suction line
fittings.
(5) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them onto the suction line
fittings.
(6) Connect the front section of the underbody suc-
tion line to the compressor section of the suction line.
Tighten the nut to 35 N´m (26 ft. lbs.).
(7) Connect the front section of the underbody suc-
tion line to the rear section of the suction line and
install the retaining bolt. Tighten the bolt to 25 N´m
(18 ft. lbs.).
(8) Lower the vehicle.
(9) Evacuate the rear refrigerant system (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(10) Charge the rear refrigerant system (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
(11) Install the cover onto the rear A/C evaporator
housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - INSTALLATION).SUCTION LINE - REAR SECTION
(1) Position the rear section of the underbody suc-
tion line to the vehicle.
(2) Install the brackets and screws that secure the
rear section of the underbody suction line to the
underneath of the vehicle. Tighten the screws to 8
N´m (70 in. lbs.).
(3) Remove the plugs or tape from the suction line
fittings.
(4) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them onto the suction line
fittings.
(5) Connect the rear section of the underbody suc-
tion line to the front section of the suction line and
install the retaining bolt. Tighten the bolt to 25 N´m
(18 ft. lbs.).
(6) Connect the rear section of the underbody suc-
tion line to the rear A/C suction line. Tighten the nut
to 35 N´m (26 ft. lbs.).
(7) Lower the vehicle.
(8) Evacuate the rear refrigerant system (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(9) Charge the rear refrigerant system (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
(10) Install the cover onto the rear A/C evaporator
housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - INSTALLATION).
VAPLUMBING 24 - 103

(3) Remove the clamp at the flexible pipe connec-
tion and the supplemental 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 heater
unit. Tighten mounting clamp securely.
(2) Position the steel exhaust pipe to the flexible
exhaust and install and tighten the mounting clamp
securely.
(3) Install the three exhaust pipe screws, adjust
pipe placement as needed and tighten the screws
securely.
(4) Install the clamp to connect the steel exhaust
pipe to the flexible exhaust pipe and tighten clamp
securely.
(5) Check exhaust pipe exhaust end placement and
make any final adjustments.
(6) Lower the vehicle.
FUEL DOSING PUMP
DESCRIPTION
The dosing pump is a combined delivery, dosing
and shut-off system for the fuel supply to the supple-
mental cabin heater from the vehicle fuel tank.
OPERATION
The dosing pump is an electrically operated pump
that receives its operation instructions from the sup-
plemental cabin heater control module. The pump
supplies diesel fuel from the vehicle fuel tank to the
cabin heater.
REMOVAL
NOTE: The dosing pump is serviceable without
removing the component from the vehicle.
(1) Disconnect the rubber hose at the fuel line to
heater fuel pump. Leave the rubber hose on the fuel
line (Refer to 24 - HEATING & AIR CONDITION-
ING/CABIN HEATER/FUEL LINE - REMOVAL)
(Fig. 2).
(2) Disconnect the fuel line between the dosing
pump and the cabin heater unit.
Fig. 1 Cabin Heater Exhaust System
1 - MOUNTING SCREW (3)
2 - STEEL HEATER EXHAUST PIPE
3 - EXHAUST CLAMP (2)4 - FLEXIBLE HEATER EXHAUST PIPE
5 - HEATER SHIELD
6 - EXHAUST PIPE MOUNTING CLIP (3)
24 - 106 CABIN HEATERVA

(3) Remove clamp from the fuel line at the fuel
tank connection and separate the line from the tank.
(4) Remove any retaining clips and remove the
fuel line from vehicle.
INSTALLATION
WARNING: Do not operate the diesel supplemental
cabin heater in an enclosed area such as a garage
that does not have exhaust ventilation facilities.
Always vent the cabin heater exhaust when operat-
ing the cabin heater. Allow the diesel supplemental
cabin heater to cool before performing any service
procedures to the cabin heater. Verify that all diesel
supplemental cabin heater fuel lines are securely
fastened to their respective components before per-
forming any service procedures to the cabin heater.
Failure to follow these warnings may result in pos-
sible personal injury or death.
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 the cabin heater fuel supply line into
vehicle and fuel line retainers.
(2) Install the fuel line connection at the fuel tank
and tighten the connection securely.(3) Install the fuel line at the dosing pump and
tighten the connection securely.
(4) Lower the vehicle.
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.
(5) Connect the DRBIIItscan tool to the diagnos-
tic link connector.
(6) 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.
Fig. 3 Cabin Heater Dosing Pump Fuel Line
1 - FUEL LINE
2 - RETAINING CLAMP3 - DOSING PUMP
4 - HEATER AIR INTAKE PIPE
VACABIN HEATER 24 - 109

(7) 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 UNIT
REMOVAL
HEATER UNIT
WARNING: Do not operate the diesel supplemental
cabin heater in an enclosed area such as a garage
that does not have exhaust ventilation facilities.
Always vent the cabin heater exhaust when operat-
ing the cabin heater. Allow the diesel supplemental
cabin heater to cool before performing any service
procedures to the cabin heater. Verify that all diesel
supplemental cabin heater fuel lines are securely
fastened to their respective components before per-
forming any service procedures to the cabin heater.
Failure to follow these warnings may result in pos-
sible 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 - DRAINING
COOLING SYSTEM).
(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 - WIRE HARNESS).
(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.
(16) Remove the cabin heater from the vehicle.
WIRE HARNESS
(1) Raise and support the vehicle while taking note
of the location of the flexible exhaust tube section.
(2) Disconnect the cabin heater wire harness con-
nector from the vehicle wiring harness.
(3) Disconnect the cabin heater wire harness con-
nector from the dosing pump.
(4) Disconnect the two cabin heater wire harness
connectors from the cabin heater controller.
(5) Remove two wiring harness retainers from the
underbody.
(6) Remove two wiring harness retainers from the
cabin heater shield.
(7) Carefully route the cabin heater wire harness
out the left side between the heater unit and the
heater shield.
INSTALLATION
HEATER UNIT
(1) Install the cabin heater mounting bracket
between the exhaust bracket and the rail mounting
location.
(2) Support the cabin heater and install the fasten-
ers that secure the cabin heater to the mounting
bracket.
(3) Install the three fasteners to the crossmem-
bers. Tighten the M6 fasteners to 7 N´m (62 in. lbs.).
24 - 110 CABIN HEATERVA

(4) Position the two spacer washers between the
body and the rubber grommets for the two mounting
points on the rail.
(5) Tighten the remaining M6 fasteners to 7 N´m
(62 in. lbs.) and the M8 fasteners to 23 N´m (17 ft.
lbs.) which mount the exhaust tube assembly to the
vehicle.
(6) Install the seat hex nut at the heater mounting
flange to the crossmembers. Tighten the nut to 60
N´m (44 ft. lbs.)
(7) Install the flexible section of the cabin heater
exhaust tube to the exhaust tube. Tighten the M6
bolt of the clamp securley. Install the hose to the
exhaust tube.
(8) Tighten the two M8 fasteners at the rail to 23
N´m (17 ft. lbs.). Taking care so that the exhaust
tube bracket tab is on the top of the heater bracket.
(9) Install the wiring harness (Refer to 24 - HEAT-
ING & AIR CONDITIONING/CABIN HEATER/
HEATER UNIT - INSTALLATION - WIRE
HARNESS).
(10) Tighten the hose and tube assembly to the
toe-board crossmember at two locations.
(11) Install the second hose to the underbody hose
and tube assembly.
(12) 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.
(13) Remove the cabin heater support device from
under the vehicle.
(14) Lower the vehicle.
(15) Fill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM FILL).
(16) Verify function of the heater unit.
WIRE HARNESS
(1) Carefully route the cabin heater wire harness
from the left side between the heater unit and the
heater shield.
(2) Install the two wiring harness retainers to the
cabin heater shield.
(3) Route the wiring harness along the underside
of the vehicle and install the two wiring harness
retainers to the underbody.
(4) Connect the two cabin heater wire harness con-
nectors to the cabin heater controller.
(5) Connect the cabin heater wire harness to the
dosing pump.
(6) Connect the cabin heater wire harness connec-
tor to the vehicle wiring harness.
(7) Lower the vehicle.
(8) Verify function of the heater unit.
INLET HOSE
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 - DRAINING
COOLING STSTEM).
(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. 4).
(5) Remove the two retaining screws and remove
pipe assembly (Fig. 5).
Fig. 4 Cabin Heater Flexible Air Intake Line
1 - CABIN HEATER AND SPLASH SHIELD
2 - DOSING PUMP
3 - DOSING PUMP FUEL LINE
4 - FLEXIBLE INTAKE LINE
5 - CLAMP
6 - STEEL INTAKE PIPE
VACABIN HEATER 24 - 111