MERCEDES-BENZ SPRINTER 2005 Service Repair Manual

SYMPTOMS DIAGNOSIS TABLE
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 DRBIIITscan tool and replace components
as required.
Continuous white smoke from heater
exhaust during combustion operation.Check 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 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.
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 ON THE CABIN HEATER SYS-
TEM IS ATTEMPTED.
(1) Raise and support the vehicle while taking note
of the location of the flexible exhaust tube section.
(2) Remove the exhaust clamp at the flexible pipe
and steel pipe connection (Fig. 1).
(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.
VACABIN HEATER 24 - 73
CABIN HEATER (Continued)

FUEL DOSING PUMP
DESCRIPTION
The dosing pump is a combined delivery, dosing
and shut-off system for the fuel supply to the supple-
mental heater from the vehicle fuel tank.
OPERATION
The dosing pump is an electrically operated pump
that receives its operation instructions from the sup-
plemental heater control module. The pump supplies
diesel fuel from the vehicle fuel tank to the supple-
mental 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 heater unit.
NOTE: Position and retain the heater fuel line to
prevent fuel leakage while servicing the dosing
pump.
NOTE: Utilize an approved fuel storage container to
catch any residual fuel.
(3) Disconnect the wiring harness connector to the
fuel pump by depressing the integral spring and pull-
ing the connector away from the pump.
(4) Remove the dosing pump from the rubber iso-
lator.INSTALLATION
(1) Install the dosing pump onto the rubber isola-
tor.
(2) Connect the fuel lines to the dosing pump and
the heater unit.
NOTE: The connectors should point towards the
heater fuel line.
Fig. 1 Diesel 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 - 74 CABIN HEATERVA
EXHAUST TUBE (Continued)

(3) Use aviation style clamps to attach the hose to
the fuel pump nipples (Refer to 24 - HEATING &
AIR CONDITIONING/CABIN HEATER/FUEL LINE
- INSTALLATION).
(4) Connect the wire harness connector to the fuel
pump by depressing the integral spring and pushing
the connector towards the dosing pump. Pull the con-
nector towards the heater to verify the installation.
(5) Verify function of the supplemental heater.
FUEL LINE
STANDARD PROCEDURE - CLEANING
(1) Remove the cabin heater fuel line (Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/FUEL LINE - REMOVAL).
(2) With the cabin heater line removed from the
vehicle, place a shop cloth on the fuel tank end of the
fuel line to catch any residue, then apply a small
amount of air pressure to the other end of the fuel
line.
(3) Check to see if air pressure is coming from the
tank end of the line. If pressure is flowing unre-
stricted the line is clean.(4) If the line shows any signs of being restricted
after air pressure is applied, the fuel line should be
replaced.
(5) Install the cabin heater line (Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/FUEL LINE - INSTALLATION).
(6) Verify function of the heater.
REMOVAL
(1) Raise and support the vehicle while taking note
of the location of the flexible exhaust tube section.
(2) Remove clamps on dosing pump end of fuel line
and separate line from the pump (Fig. 3).
NOTE: Have an approved fuel holding device ready
to capture any diesel fuel that drains from the fuel
line or heater unit.
(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.
Fig. 2 Dosing Pump Fuel Line
1 - FUEL LINE
2 - RETAINING CLAMP3 - DOSING PUMP
4 - HEATER AIR INTAKE PIPE
VACABIN HEATER 24 - 75
FUEL DOSING PUMP (Continued)

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 the 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 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 DRBIIItscan tool to the Diagnos-
tic Link Connector.
(6) Turn the ignition to the ON position.
Fig. 3 Dosing Pump Fuel Line
1 - FUEL LINE
2 - RETAINING CLAMP3 - DOSING PUMP
4 - HEATER AIR INTAKE PIPE
24 - 76 CABIN HEATERVA
FUEL LINE (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 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
REMOVAL
WARNING: ALLOW THE SUPPLEMENTAL HEATER
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) Raise and support the vehicle. Take note of the
location of the flexible exhaust tube section.
(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 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 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 heater exhaust tube flex section
from the exhaust tube by loosening the 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 fasteners which mount
the exhaust tube assembly to the vehicle.
(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 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.
REMOVAL
(1) Raise and support the vehicle while taking note
of the location of the flexible exhaust tube section.
(2) Unplug the wire harness connector from vehi-
cle wiring harness to cabin heater harness.
(3) Unplug the wire harness connector from cabin
heater harness to dosing pump connector.
(4) Unplug the two wire harness connectors from
cabin heater harness to cabin heater controller con-
nectors.
(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.
VACABIN HEATER 24 - 77
FUEL LINE (Continued)

INSTALLATION
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 fasteners to the cross mem-
bers. Tighten the M6 fasteners to 7 N´m (62 in. lbs.).
(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 cross members. Tighten the nut to 60
N´m (44 ft. lbs.)
(7) 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.
(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).
(10) Tighten the hose and tube assembly to the
toe-board cross member 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 heater unit support device from
under the vehicle.
(14) Lower the vehicle.
(15) Fill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(16) Verify function of the cabin heater.
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.
INLET HOSE
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 the engine 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. 4).
(5) Remove the two retaining screws and remove
pipe assembly (Fig. 5).
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 heater air intake
muffler and install and tighten the retaining clamp
securely.
24 - 78 CABIN HEATERVA
HEATER UNIT (Continued)

(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 engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(7) Verify function of the heater unit.
Fig. 4 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
Fig. 5 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
VACABIN HEATER 24 - 79
INLET HOSE (Continued)

EMISSIONS CONTROL
EXHAUST GAS RECIRCULATION
TABLE OF CONTENTS
page page
VA LV E
DESCRIPTION..........................1
OPERATION............................1REMOVAL.............................2
INSTALLATION..........................2
VA LV E
DESCRIPTION
Exhaust gas recirculation reduces the quantity of
fresh air supplied to the cylinders per stroke without
having to throttle the air supply. As a result, emis-
sions are reduced. If a quantity of exhaust gas is
mixed with the air that is to be used to burn the fuel
in the cylinders, the oxygen content is reduced,
because the exhaust gas is low in oxygen. The result
is that the combustion rate is reduced, as is the com-
bustion temperature. This reduces the quantity of
NOx that are emitted in the exhaust gas (Fig. 1).
OPERATION
The mass of the air supplied to the cylinders per
stroke is the decisive factor for determining the opti-
mum quantity of exhaust gas for the operating con-
dition. This is calculated from the Mass Air Flow
sensor information.
The ECM evaluates this signal as well as that
from the Charge Air Pressure sensor, and outputs a
PWM signal in accordance with one of the maps
stored in it. The signal is sent to the exhaust gas
recirculation valve. The map is formulated to keep
the NOx as low as possible. The EGR valve is actu-
ated by an electric positioning motor.
Fig. 1 EXHAUST GAS RECIRCULATION
1 - E G R VA LV E
2 -CHARGE AIR PRESSURE SENSOR
3 - EXHAUST MANIFOLD
4 - EGR DUCT IN CYLINDER HEAD
5 - INTAKE MANIFOLD
VAEMISSIONS CONTROL 25 - 1

REMOVAL
(1) Disconnect the negative battery cable.
(2) Lift up on the charge air hose retaining clip at
the mixing chamber and disconnect hose with seal
(Fig. 2).
(3) Disconnect the electrical connector at the EGR
positioner (Fig. 2).
(4) Remove mixing chamber support bracket (Fig.
2).
(5) Remove the mixing chamber retaining bolts
and remove chamber (Fig. 2).
INSTALLATION
(1) Clean all gasket mating surfaces.
(2) Position the mixing chamber to the intake
manifold with a new gasket, install bolts and tighten
to 124 lbs.in (14 N´m) (Fig. 2).
(3) Install the mixing chamber support bracket
and tighten the bolts to 124 lbs.in (14 N´m) (Fig. 2).
(4) Connect the EGR positioner electrical connec-
tor (Fig. 2).
(5) Inspect the seal of the charge air inlet tube,
replace as necessary (Fig. 2).
(6) Seat the charge air tube with gasket into the
mixing chamber and push down on the charge air
tube retaining clip (Fig. 2).
(7) Connect negative battery cable.
Fig. 2 MIXING CHAMBER AND EGR POSITIONER
1 - EGR POSITIONER
2 - GASKET
3 - MIXING CHAMBER
4 - CHARGE AIR HOSE RETAINING CLIP
5 - GASKET
6 - CHARGE AIR HOSE
7 - BRACKET
8 - BOLT
25 - 2 EXHAUST GAS RECIRCULATIONVA
VALVE (Continued)