2006 MERCEDES-BENZ SPRINTER engine coolant

INSTALLATION
(1) Install the electric coolant pump and mounting
bracket onto the body studs.
(2) Install the two bracket retaining nuts. Tighten
the nuts to 5 N´m (45 in. lbs.).
(3) Using a twisting motion gently install both
hoses onto the electric coolant pump.
(4) Tighten both hose clamps securely.
(5) Connect the wire harness connector to the elec-
tric coolant pump.
(6) Reconnect the negative battery cable.
(7) Fill the engine cooling system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE - COOLING SYSTEM FILL).
HEATER CORE
DESCRIPTION
The heater core is mounted into the HVAC hous-
ing, located behind the instrument panel (Fig. 14).
The heater core is a heat exchanger made of rows of
tubes and fins. The heater core tubes are attached to
the heater core by using O-ring seals and bolts.
The heater core is serviced by removing and disas-
sembling the HVAC housing.
OPERATION
Engine coolant is circulated through the heater
hoses to the heater core whenever the heater water
valve is cycled open by the ATC A/C-heater control.
As the coolant flows through the heater core, heat
removed from the engine is transferred to the heater
core fins and tubes. Air directed through the heater
core picks up the heat from the heater core fins. The
heater water valve controls the heater output air
temperature by controlling the amount of heated
engine coolant flowing through the heater core. The
blower motor speed controls the volume of air flowing
through the HVAC housing.
The heater core cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (ground) cable, then wait two
minutes for the system capacitor to discharge
before performing further diagnosis or service. This
is the only sure way to disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
Fig. 13 Electric Coolant Pump
1 - HEATER HOSE
2 - HOSE CLAMP (2)
3 - HEATER HOSE
4 - ELECTRIC COOLANT PUMP
5 - WIRE HARNESS CONNECTOR
6 - NUT (2)
Fig. 14 Front Heater Core
1 - HEATER CORE
2 - BOLT (3)
3 - HEATER CORE TUBES
4 - O-RING SEALS
24 - 76 PLUMBINGVA

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.
(1) Remove the heater housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(2) Disassemble the HVAC housing to access the
heater core (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION/HVAC HOUSING - DIS-
ASSEMBLY).
(3) Lift the heater core out of the lower half of the
HVACr housing (Fig. 15).
(4) If necessary, remove the three heater core tube
retaining bolts and the heater core tube assembly
from the heater core.
(5) Remove the heater core tube seals and discard
as required.INSTALLATION
(1) If the heater core tube assembly was removed
from the heater core, lubricate two new rubber
O-ring seals with clean engine coolant and install
them onto the heater core fitting.
(2) If required, connect the heater core tube
assembly to the heater core and install the three
retaining bolts. Tighten the bolts to 5 N´m (45 in.
lbs.).
(3) Install the heater core into the bottom half of
the HVAC housing.
(4) Assemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
NOTE: If the heater core is being replaced, flush the
cooling system (Refer to 7 - COOLING - STANDARD
PROCEDURE - COOLING SYSTEM CLEANING/RE-
VERSE FLUSHING).
(5) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
LIQUID LINE
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 A/C liquid line is serviced in two sec-
tions. The front section connects between the A/C
condenser and the receiver/drier and includes the
high side service port and the A/C pressure sensor
on the fitting for the receiver/drier. The rear section
connects between the receiver/drier and the A/C
expansion valve.
FRONT SECTION
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
(2) Disconnect and isolate they negative batter
cable.
(3) Remove the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL).
Fig. 15 HVAC Housing
1 - SCREW (12)
2 - UPPER HOUSING
3 - A/C EVAPORATOR
4 - EVAPORATOR O-RING SEAL (2)
5 - EVAPORATOR GASKET
6 - VENTILATION HOUSING GASKET
7 - LOWER HOUSING
8 - WIRING HARNESS
9 - BOLT (3)
10 - HEATER CORE
11 - HEATER CORE TUBE ASSEMBLY
12 - HEATER CORE TUBE GASKET
13 - HEATER CORE TUBE O-RING SEAL (2)
VAPLUMBING 24 - 77

(12) Install the plastic routing clip retainer onto
the A/C suction line.
(13) Reconnect the negative battery cable.
(14) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(15) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
WATER VALVE
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Partially drain the engine cooling system
(Refer to 7 - COOLING/ENGINE/COOLANT - STAN-
DARD PROCEDURE - DRAINING COOLING SYS-
TEM).
(3) Disconnect the wire harness connector from the
heater water valve (Fig. 21).
(4) Loosen the hose clamps from the heater water
valve.
(5) Using a twisting motion gently remove the
heater hoses from the heater water valve.
(6) Remove the bolts that secure the heater water
valve bracket.
(7) Remove the bracket and pulsed water control
valve from the engine compartment.
(8) Turn the bracket slightly and remove the water
valve from the rubber mounts.
(9) If necessary, remove the rubber mounts from
the bracket or water valve.
INSTALLATION
(1) If removed, install the rubber mounts to the
heater water valve or bracket.
(2) Turn bracket slightly to the right and install
the heater water valve to the bracket.
(3) Install the water valve and mounting bracket
into the engine compartment.
(4) Install the two bracket retaining bolts. Tighten
the bolts to 5 N´m (45 in. lbs.).
(5) Using a twisting motion gently install the
heater hoses onto the water valve.
(6) Tighten the hose clamps securely.
(7) Connect the wire harness connector to the
heater water valve.
(8) Reconnect the negative battery cable.
(9) Fill the engine cooling system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE - COOLING SYSTEM FILL).
REARA/CCONDENSER FAN
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the cover from the rear A/C condenser
housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C CON-
DENSER COVER - REMOVAL).
Fig. 21 Heater Water Valve
1 - HEATER WATER VALVE
2 - HOSE CLAMP (3)
3 - HEATER HOSE (3)
4 - RUBBER MOUNT (2)
5 - BOLTS (2)
6 - BRACKET
7 - RUBBER MOUNT
VAPLUMBING 24 - 83

CABIN HEATER
TABLE OF CONTENTS
page page
CABIN HEATER
DESCRIPTION........................104
OPERATION..........................104
DIAGNOSIS AND TESTING
SUPPLEMENTAL CABIN HEATER........104
EXHAUST TUBE
REMOVAL............................105
INSTALLATION........................106
FUEL DOSING PUMP
DESCRIPTION........................106
OPERATION..........................106
REMOVAL............................106
INSTALLATION........................107
FUEL LINE
STANDARD PROCEDURE
CLEANING.........................107REMOVAL............................108
INSTALLATION........................109
HEATER UNIT
REMOVAL
HEATER UNIT.......................110
WIRE HARNESS.....................110
INSTALLATION
HEATER UNIT.......................110
WIRE HARNESS.....................111
INLET HOSE
REMOVAL............................111
INSTALLATION........................112
CABIN HEATER
DESCRIPTION
Vehicles equipped with the diesel engine are also
equipped with a supplemental cabin heater. This
cabin heater is mounted under the vehicle and oper-
ates similar to an oil fired furnace. The heater burns
small amounts of fuel to provide additional heat to
the coolant. Coolant is routed from the engine, to the
supplemental cabin heater and then to the front
heater core. This provides additional heat to the pas-
senger compartment. The supplemental cabin heater
system is interfaced to the vehicles on-board com-
puter systems and DRBIIItdiagnostics.
The supplemental cabin heater has an electronic
control module that monitors the heat output of the
heater. The cabin heater operates at full load (5 kW),
half load or idle mode (no additional heat) depending
on engine coolant temperature.
OPERATION
The supplemental cabin heater is activated by
using the temperature control on the A/C-heater con-
trol. The supplemental cabin heater is activated
when the temperature control is set to/or above the
upper set point. The supplemental cabin heater can
operate in a full or partial load range as well as an
idle mode, all dependent on the engine coolant tem-
perature. The heater unit will also turn off if the
temperature control is set to less than the lower set
point. The supplemental cabin heater can take up to
three minutes to completely shut down when eitherthe heater temperature is set below the lower set
point or the vehicle ignition is turned off.
The supplemental cabin heater only operates when
the engine is running, the mileage exceeds 8 kilome-
ter (5 mph) and the fuel tank volume exceeds 1/8 of a
tank. The heater should start if the coolant temper-
ature is below 40É C (104É F).
NOTE: Do not apply a strong vacuum directly on
the supplemental cabin heater exhaust line. Place
the vacuum within 75 mm (3 inches) of the exhaust
port. Too strong of a vacuum can prevent the heater
from starting. The heater control module monitors
the blower speed and combustion during its start-
up.
DIAGNOSIS AND TESTING
SUPPLEMENTAL CABIN HEATER
Refer to the Symptoms Diagnosis table for basic
checks of the diesel fueled supplemental cabin heater.
24 - 104 CABIN HEATERVA

(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

EXHAUST GAS RECIRCULATION
TABLE OF CONTENTS
page page
EXHAUST GAS RECIRCULATION
DESCRIPTION..........................4
VA LV E
DESCRIPTION..........................5
OPERATION............................6REMOVAL.............................6
INSTALLATION..........................6
VALVE COOLER
DESCRIPTION..........................6
EXHAUST GAS RECIRCULA-
TION
DESCRIPTION
The EGR system can provide up to 35% exhaust
gas recirculation. The EGR operates during all
engine speed and load conditions. At wide open throt-
tle, it provides a 5% recirculation rate. The EGR
shuts down during high engine idle to avoid carbon
build up on the valve. The EGR also deactivates if
the EGR temperature is too high. The EGR also has
a self cleaning function that opens and closes twice
after the engine has been shut off to eliminate soot
deposits.
Apart from the charge air distribution manifold
and the mixing chamber, the intake manifold also
includes a finned EGR cooler. Coolant flows through
the cooler to reduce the temperature of the recircu-
lated gas after it was cooled by running through the
cylinder head. The management of this temperature
significantly reduces emissions (Fig. 1).
25 - 4 EXHAUST GAS RECIRCULATIONVA

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. Exhaust gas is
recirculated during all engine speed and engine load
conditions. As a result, emissions 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 oxy-
gen content is reduced because the exhaust gas is
low in oxygen. The result is that the combustion rate
is reduced, as is the combustion temperature. This
reduces the quantity of NOx that are emitted in the
exhaust gas. (Fig. 2).
The ECM power supply relay has a power off delay
feature. The relay is powered off approximately 15
seconds after the ignition switch is turned off. This
allows for the self-cleaning function of the EGR valve
and a function check of the sensors for diagnosis pur-
poses.
Fig. 1 EGR AND COOLER
1 - EGR VALVE 3 - COOLING FINS
2 - COOLANT PASSAGE 4 - EXHAUST GAS PASSAGE
VAEXHAUST GAS RECIRCULATION 25 - 5

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 and has a self
cleaning function. Every time the ignition switch is
turned off, the valve rotates twice to eliminate any
carbon deposits.
REMOVAL
NOTE: The EGR and EGR Cooler are serviced as an
assembly.
(1) Disconnect the negative battery cable.
(2) Partailly drain the cooling system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE).
(3) Lift up on the charge air hose retaining clip at
the intake manifold and disconnect hose with seal
(4) Disconnect the electrical connector at the EGR
positioner (Fig. 3).(5) Disconnect the EGR cooler hose.
(6) Remove the EGR fasteners and EGR with
cooler assembly (Fig. 3).
INSTALLATION
(1) Clean all gasket mating surfaces.
(2) Position the EGR positioner to the intake man-
ifold with a new gasket, install bolts and tighten to
124 lbs.in (14 N´m) (Fig. 3).
(3) Connect the EGR positioner electrical connec-
tor (Fig. 3).
(4) Inspect the seal of the charge air inlet tube,
replace as necessary (Fig. 3).
(5) Seat the charge air tube with gasket into the
intake manifold and push down on the charge air
tube retaining clip.
(6) Refill the cooling system (Refer to 7 - COOL-
ING/ENGINE/COOLANT - STANDARD PROCE-
DURE).
(7) Connect negative battery cable.
VALVE COOLER
DESCRIPTION
The exhaust gas recirculation (EGR) cooler is an
integrated part of the EGR valve. Coolant flows
around the exhaust gasses, cooling them before they
are remixed with the incoming air and reburned in
the combustion chamber (Fig. 4).
Fig. 2 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
Fig. 3 EGR VALVE
1 - E G R VA LV E
2 - INTAKE MANIFOLD
3 - EGR COOLER HOSE
4 - HARNESS CONNECTOR
25 - 6 EXHAUST GAS RECIRCULATIONVA