2006 MERCEDES-BENZ SPRINTER sensor

If a high-pressure line connection is leaking, coun-
terhold and tighten the connection to specification
then perform this procedure again (Refer to 14 -
FUEL SYSTEM - STANDARD PROCEDURE).
Replace any damaged, restricted or leaking high-
pressure fuel lines with the correct replacement
line.
CAUTION: The high-pressure fuel lines cannot con-
tact each other or other components. Do not
attempt to weld high-pressure fuel lines or to repair
lines that are damaged. Only use the recommended
lines when replacement of high-pressure fuel line is
necessary.
DIAGNOSIS AND TESTING - AIR IN FUEL SYS-
TEM
Air will enter the fuel system whenever fuel supply
lines, separator filters, injection pump, high-pressure
lines or injectors are removed or disconnected. Air
trapped in the fuel system can result in hard start-
ing, a rough running engine, engine misfire, low
power, excessive smoke and fuel knock.
Inspect the fuel system from the fuel tank to the
injectors for loose connections (Refer to 14 - FUEL
SYSTEM - WARNING). Leaking fuel is an indicator
of loose connections or defective seals. Air can also
enter the fuel system between the fuel tank and the
fuel pump. Inspect the fuel tank module and fuel
lines for damage that might allow air into the sys-
tem.With the DRBIIItconnected to the vehicle, select
Engine and the select Sensor Display. Page down to
view Fuel Pressure Set Point and Actual Fuel Pres-
sure. Start the engine and observe the Fuel Pressure
Set Point and the Actual Fuel Pressure. If the Actual
Fuel Pressure Oscillates above and below the Fuel
Pressure Set Point in a regular cycle, inspect the fuel
system for air intrusion.
If the Actual Fuel Pressure gradually drops below
the Fuel Pressure Set Point then spikes well above
the Fuel Pressure Set Point, replace the fuel pres-
sure soleniod (Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/FUEL PRESSURE SOLENOID -
REMOVAL), and recheck.
DIAGNOSIS AND TESTING - INJECTOR LEAK
QUANTITY
WARNING: REVIEW THE HIGH PRESSURE FUEL
SYSTEM WARNING BEFORE BEGINNING SERVICE
(Refer to 14 - FUEL SYSTEM - WARNING).
CRANKING TEST
NOTE: If an injector is found to be out of specifica-
tion, repeat this test procedure after the injector
replacement. Hydraulic flow will take the path of
least resistance and multiple failures may be identi-
fied.
Perform this test with the engine at operating tem-
perature, when possible. This test will assist in
determining a defective or internally leaking injec-
tor(s) is present by measuring the amount of fuel
return.
(1) Turn the ignition off.
(2) Remove the engine cover (Refer to 9 - ENGINE
- REMOVAL).
(3) Disconnect the fuel return hoses at the top of
the injectors.
(4) Pinch off the fuel return line at the banjo bolt
fitting of the fuel rail.
(5) Disconnect the fuel rail solenoid and camshaft
position sensor.
(6) Install the test vials onto the injectors and
secure with the return hose clips (Fig. 2).
Fig. 1 Typical Test for Leaks with Cardboard
1 - HIGH-PRESSURE LINE
2 - CARDBOARD
3 - FITTING
14 - 2 FUEL SYSTEMVA

STANDARD PROCEDURE - LOW PRESSURE
FUEL PUMP TEST
NOTE: Assure fuel tank quantity and proper fuel
gauge operation. Assure that the fuel pump fuse or
relay is not open. Capture any fuel spillage and
store in appropriately marked containers.
NOTE: When the ignition switch is turned to the ON
position the fuel pump will begin to run for 20±30
seconds and then it stops.
The low pressure pump draws fuel out of the fuel
tank module and pushes the fuel towards the fuel fil-
ter. If the pressure reading is below specification,
look for damaged or leaking fuel lines or a restricted
fuel filter. If no problem is found with the fuel sys-
tem replace the low pressure fuel pump.
(1) Disconnect the negative battery cable.
(2) Connect a fuel gauge to the low pressure fuel
supply to the high pressure pump (Fig. 4).(3) Connect negative battery cable.
(4) Turn the ignition to the ON position and
observe the fuel gauge reading (Fig. 5).
(5) The fuel pressure should be 4.0 to 4.5 bar (58 -
65 psi) If the fuel pressure is below specification,
Fig. 3 WATER IN FUEL SENSOR
1 - WIF SENSOR
2 - WIF DRAIN
3 - FUEL FILTER
4 - FUEL SUPPLY FROM TANK
5 - FUEL SUPPLY TO HIGH PRESSURE PUMP
Fig. 4 FUEL GAUGE CONNECT AT HIGH PRESSURE
PUMP
1 - FUEL SUPPLY FITTING
2 - ADAPTOR
3 - FUEL GAUGE HOSE
4 - HIGH PRESSURE PUMP
5 - FUEL RETURN FITTING
Fig. 5 FUEL PRESSURE TEST AT HIGH PRESSURE
PUMP
14 - 4 FUEL SYSTEMVA

FUEL DELIVERY
TABLE OF CONTENTS
page page
FUEL DELIVERY
DESCRIPTION..........................6
OPERATION............................7
STANDARD PROCEDURE
STANDARD PROCEDURE - DRAINING
FUEL TANK - DIESEL...................8
FUEL CONTAMINATION.................8
SPECIFICATIONS
TORQUE.............................9
SPECIAL TOOLS
FUEL SYSTEM........................9
FUEL DRAIN TUBES
DIAGNOSIS AND TESTING - FUEL SUPPLY
RESTRICTIONS.......................10
FUEL FILTER
DESCRIPTION.........................10
REMOVAL.............................10
INSTALLATION.........................11
FUEL LINES
REMOVAL - HIGH PRESSURE LINES........11
INSTALLATION - HIGH PRESSURE LINES....12
FUEL RAIL PRESSURE SENSOR
DESCRIPTION.........................12
OPERATION...........................12
REMOVAL.............................12
INSTALLATION.........................13
FUEL PUMP
DESCRIPTION
DESCRIPTION - HIGH PRESSURE PUMP . . . 13
DESCRIPTION - LOW PRESSURE PUMP . . . 13OPERATION
OPERATION.........................13
OPERATION - LOW PRESSURE PUMP.....16
REMOVAL - HIGH PRESSURE PUMP........17
INSTALLATION - HIGH PRESSURE PUMP....17
FUEL PUMP MODULE
DESCRIPTION.........................18
REMOVAL.............................18
INSTALLATION.........................20
FUEL QUANTITY CONTROL VALVE
DESCRIPTION.........................21
OPERATION...........................21
REMOVAL.............................21
INSTALLATION.........................21
FUEL RAIL
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................22
FUEL TANK
DESCRIPTION.........................23
REMOVAL.............................25
INSTALLATION.........................26
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION.........................28
REMOVAL.............................29
INSTALLATION.........................29
WATER IN FUEL SENSOR
DESCRIPTION.........................30
OPERATION...........................30
FUEL DELIVERY
DESCRIPTION
Fuel is collected in the fuel tank. The fuel is drawn
in by the fuel pump module in the tank and distrib-
uted to the fuel filter and onto the high pressure fuel
pump. From there the fuel is distributed onto the
fuel rail and then to the various injectors. Any fuel
not needed flows back to the fuel tank through the
cooler lines and mixes with the cool fuel in the fuel
pump module bowl to be used again (Fig. 1).
14 - 6 FUEL DELIVERYVA

OPERATION
There are several modes of operation for the Com-
mon Rail Diesel Injection System.
Pre-injection The purpose of the pre-injection func-
tion is to reduce noise and pollutants. The coolant
temperature, charge air temperature and atmo-
spheric pressure are use to correct the quantity of
pilot injection. The quantity of pilot injection now
determined is deducted from the quantity of main
injection in order to establish whether sufficient
quantity is available for the following main injection.
The rail pressure is chosen sufficiently high so that
a minimum quantity is injected. If the quantity of
main injection is too small the pilot injection is
switched off by the ECM.
The start of actuation of pilot injection is calcu-
lated dependent on operating point, the following
data being taken into account:
Shutting Off Pre-injection The pre-injection is shut
off when:
²The moment of pre-injection is exceeded
²Engine speed too high
²Pre-injected quantity too low
²Main injected quantity too low²Insufficient fuel rail pressure
²Engine is switched off
Calculating Pre-injection Quantity The pre-injec-
tion quantity is calculated on the basis of:
²Engine speed
²Atmospheric pressure
²Coolant temperature
²Boost air temperature
²Fuel rail pressure
Main Injection The purpose of main injection func-
tion is to enable the injection time and injection
period calculated by the ECM. The injection quantity
required by the engine is divided into the per-injec-
tion and main injection quantity. If the main injec-
tion quantity computed by the ECM is too small, no
pre-injection takes place.
Start of Actuation
The start of actuation of main injection is depen-
dent on engine speed and quantity. In addition, it is
corrected depending on the following values:
²Coolant temperature
²Boost air temperature
²Atmospheric pressure
²Pre-injection corrected YES/NO
Fig. 1 FUEL SUPPLY
1 - HIGH PRESSURE FUEL PUMP 8 - FUEL INJECTOR
2 - FUEL FROM LOW PRESSURE PUMP 9 - HIGH PRESSURE FUEL FROM HIGH PRESSURE PUMP
3 - FUEL FILTER 10 - FUEL PRESSURE SOLENOID
4 - LOW PRESSURE FUEL PUMP 11- FUEL RAIL
5 - FUEL TANK 12 - FUEL RAIL PRESSURE SENSOR
6 - RETURN FUEL 13 - FUEL QUANTITY CONTROL VALVE
7 - HIGH PRESSURE FUEL FROM HIGH PRESSURE PUMP 14 - FUEL TEMPERATURE VALVE
VAFUEL DELIVERY 14 - 7

Switching Off Main Injection
Main injection is switched off when:
²Engine speed is too high >4700 - 4800 rpm
²Main injection quantity too low
²Low fuel pressure in fuel rail
²Engine off
²External quantity control
²Deceleration mode
Calculating Main Injection
The quantity of main injection is calculated by:
²Engine speed
²Atmospheric pressure
²Coolant temperature
²Boost air temperature
²Fuel rail pressure
²Boost pressure
Period of Actuation
For calculating the period of actuation of the main
injection it is necessary to know whether a pre-injec-
tion has occurred or not.
The coolant temperature, charge air temperature
and the atmospheric pressure are used for correcting
the main injection quantity. If main injection quan-
tity is less than a minimum quantity which is depen-
dent on fuel rail pressure, no preinjection takes
place. In this case, only main injection is performed.
If the quantity is then still below the minimum
quantity, neither main injection or pre-injection takes
place (deceleration mode).
Deceleration Mode
The purpose of the deceleration mode is to inter-
rupt the operation of the injectors. The ECM deter-
mines the accelerator pedal position from a supplied
signal and it determines the engine speed by the
crank sensor. In the overrun and with the engine
speed above 1600, with the accelerator pedal no
pressed, the injectors are no longer actuated and the
fuel rail pressure is lowered by the pressure regula-
tor valve.
Full Load Injected Quantity
The purpose of the full load injected quantity is to
minimize the formation of smoke. The ECM limits
the fuel rail pressure when the engine is operating at
full load by way of the quantity control valve, and
quantity of fuel injected by the injectors. this mini-
mizes the formation of smoke when accelerating and
driving at constant speeds. If a fault occurs at the
boost pressure control, full load injected quantity is
reduced.
Limiting Maximum Engine Speed
The ECM determines the engine speed based on
the signal supplied by the crankshaft sensor and lim-its this by interrupting the operation of the fuel
injectors.
Fuel Quantity Control
The fuel quantity is controlled separately for each
cylinder by the ECM inline with the firing order.The
ECM detects the operating state which exists at the
engine by means of the sensors. In order adapt the
quantity injected, either the fuel rail pressure can be
adjusted by the fuel solenoid and quantity control
valve or the actuation time of the solenoid valves in
the injectors
Boiling Protection
In order to protect against thermal overload and
along with criteria programmed in the ECM, the
injection quantity is reduced as a function of the cool-
ant temperature and vehicle speed. If the coolant
temperature sensor fails the oil temperature signal
from the oil sensor is used as a suitable value.
Fuel Tank Protection
The fuel rail pressure is lowered in order to protect
the fuel tank from overheating. The fuel temperature
sensor measures the temperature of the fuel being
supplied from the tank, in the high pressure flange.
If the fuel is too warm the fuel rail pressure is fur-
ther reduced by the quantity control valve.
STANDARD PROCEDURE
STANDARD PROCEDURE - DRAINING FUEL
TANK - DIESEL
(1) Position a drain hose into the fuel fill opening.
(2) Drain fuel tank using an approved diesel fuel
draining station.
FUEL CONTAMINATION
If a diesel engine's fuel supply has been contami-
nated with gasoline, the following procedure must be
followed:
(1) Remove all fuel from the fuel tank. (Refer to 14
- FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE-DRAINING FUEL TANK) Use an
appropriate fuel container. Dispose of the contami-
nated fuel using the proper procedures.
CAUTION: Dispose of petroleum based products in
a manner consistent with all applicable Local, State,
Federal, and Provincial regulations.
(2) Remove and clean fuel tank. (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL TANK -
REMOVAL)
(3) Install the fuel tank. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/FUEL TANK - INSTALLA-
TION)
14 - 8 FUEL DELIVERYVA

FUEL DRAIN TUBES
DIAGNOSIS AND TESTING - FUEL SUPPLY
RESTRICTIONS
LOW - PRESSURE LINES
Fuel supply line restrictions can cause starting
problems and prevent engine from accelerating. The
starting problems include; low power and/or white
fog like exhaust.
Test all fuel supply lines for restrictions or block-
age. Flush or replace as necessary.
HIGH - PRESSURE LINES
CAUTION: High pressure lines cannot contact each
other or other components. Do not attempt to weld
high-pressure fuel lines or to repair lines that are
damaged. High pressure lines must be replaced at
each disassembly. Use only recommended lines
when replacement of high-pressure fuel line is nec-
essary.
Restricted (kinked or bent) high-pressure lines can
cause starting problems, poor engine performance,engine mis-fire and white smoke from exhaust (Refer
to 14 - FUEL SYSTEM - WARNING).
FUEL FILTER
DESCRIPTION
The fuel filter was designed for improved high alti-
tude operation and for better re-start after the fuel
tank has been completely emptied. The water drain
plug and water in fuel (WIF) sensor are located on
the top of the filter. Water is drained by using the in-
tank electric fuel pump to generate flow (attach a
hose to the drain plug). The filter has a pressure dif-
ferential of 200±300 mbar (2.9 psi.) when new. When
dirty, the pressure differential rises to 800 mbar (11.6
psi.) (Fig. 2).
REMOVAL
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
CAUTION: DO NOT bend, twist or cut the fuel hose
clamps. The fuel hose clamps through out the fuel
system are reusable when using special tool #9539.
Orginal clamps must be used when servicing the
fuel system.
(1) Disconnect negative battery cable.
(2) Disconnect the water in fuel (WIF) sensor har-
ness connector (Fig. 2).
(3) Release the fuel inlet and outlet hose clamps
using special tool #9539 at the fuel filter (Fig. 2).
(4) Remove fuel filter retaining bracket bolt and
remove fuel filter (Fig. 2).
(5) Separate the WIF sensor from the fuel filter
(Fig. 2)
FUEL LINE WRENCH-9285
FUEL LINE PLIERS-9539
14 - 10 FUEL DELIVERYVA

INSTALLATION
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
CAUTION: DO NOT bend, twist or cut the fuel hose
clamps. The fuel hose clamps through out the fuel
system are reusable when using special tool #9539.
Orginal clamps must be used when servicing the
fuel system.
NOTE: Capture any fuel spillage and dispose of in
appropriately marked container.
(1) Fill new fuel filter with the new diesel fuel
(approximately 0.4 liters)
(2) Carefully seat WIF sensor and tighten bolt to
13 lbs. in. (1.5 N´m) (Fig. 2)
(3) Position fuel filter in bracket and tighten
retaining bolt to 53 lbs. in. (6 N´m) (Fig. 2)
(4) Install fuel lines and re-crimp clamps using
special tool #9539 (Fig. 2).
(5) Connect the WIF wiring harness connector
(Fig. 2).
(6) Connect negative battery cable.(7) Cycle ignition several times to build pressure.
(8) Start engine and inspect for leaks.
FUEL LINES
REMOVAL - HIGH PRESSURE LINES
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
(1) Disconnect negative battery cable.
CAUTION: Counterhold with wrench at threaded
connections of injectors. DO NOT EXCEED the
tightening torque in order to avoid also slackings
the threaded connection.
CAUTION: DO NOT crimp or bend lines.
NOTE: After removing injection lines, seal connec-
tions and ensure cleanliness.
(2) Unscrew union nuts of injection lines.
(3) Remove injection lines (Fig. 3).
Fig. 2 FUEL FILTER
1 - FUEL SUPPLY LINE TO HIGH PRESSURE PUMP
2 - FUEL FILTER
3 - WIF SENSOR
4 - FUEL FILTER DRAIN
VAFUEL DELIVERY 14 - 11

INSTALLATION - HIGH PRESSURE LINES
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
(1) Loosen the fuel rail mounting bolts to install
lines free of stress.
CAUTION: Inspect sealing cone at lines. Replace if
compression points exist. Ensure lines are exactly
located.
(2) Position and install fuel lines (Fig. 3). Tighten
to 22N´m (195 lbs. in.) using a wrench to counterhold
at threaded connection.
(3) Tighten fuel rail to 14N´m (124 lbs. in.).
(4) Connect negative battery cable.
CAUTION: Care must be taken when installing the
engine cover. Assure the proper routing of the fuel
injector return fuel hose to the banjo bolt fitting in
the left rear corner of the cover. Failure to do so
may pinch or damage the hose causing fuel leakage
or a driveability concern.(5) Start engine, run for a few minutes, turn
engine off and inspect for leaks (Refer to 14 - FUEL
SYSTEM - WARNING), (Refer to 14 - FUEL SYS-
TEM - DIAGNOSIS AND TESTING).
FUEL RAIL PRESSURE SEN-
SOR
DESCRIPTION
The fuel rail pressure sensor is attached to the
front of the fuel rail. The sensor supplies the current
fuel rail pressure to the ECM.
OPERATION
Non-constant fuel system pressure influences the
position of a diaphragm inside the sensor. This
results in a variation in the electrical resistance. The
fuel rail pressure sensor supplies the appropriate
voltage signal to the ECM.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the sensor wiring harness connector
(Fig. 4).
NOTE: Place a shop towel underneath the sensor to
capture any fuel spillage.
(3) Unscrew the sensor and discard the seal.
Fig. 3 FUEL RAIL
1 - CAMSHAFT POSITION SENSOR
2 - FUEL INJECTOR
3 - FUEL INJECTOR VALLEY DRAIN
4 - FUEL RAIL PRESSURE CONTROL VALVE
5 - BANJO BOLT
6 - FUEL RAIL
7 - HIGH PRESSURE FUEL LINE
Fig. 4 FUEL RAIL PRESSURE SENSOR
1 - FUEL RAIL PRESSURE SENSOR
2 - FUEL RAIL
3 - COOLANT TEMPERATURE SENSOR
14 - 12 FUEL DELIVERYVA