Mercedes-Benz Sprinter / Dodge Sprinter. Service manual — part 419

(2) Position the sensor (Fig. 3) and install the fas-

teners.

(3) Connect the negative battery cable.

BOOST PRESSURE SENSOR

DESCRIPTION

The boost pressure sensor is mounted to the charge

air pipe (Fig. 4). The sensor allows the ECM to mon-
itor intake air down stream of the turbocharger.

OPERATION

When the intake manifold pressure is high due to

turbo boost, sensor voltage output is 2.0-4.7 volts.
The sensor receives a 5-volts reference from the
ECM. Sensor ground is also provided by the ECM.
The ECM uses boost pressure combined with intake
air temerature to determine the volume of air enter-
ing the engine (Fig. 4).

DIAGNOSIS AND TESTING - BOOST PRESSURE
SENSOR

If the boost pressure sensor fails, the ECM records

a DTC into memory and continues to operate the
engine in one of the three limp-in modes. When the
ECM is operating in this mode, a loss of power will
be present, as if the turbocharger was not operating.
The best method for diagnosing faults with the boost
pressure sensor is with the DRB III

t scan tool. Refer

to the Diesel Powertrain Diagnostic Manual for more
information.

Refer to On-Board Diagnostics in Emissions Con-

trol System for a list of Diagnostic Trouble Codes
(DTC’s) for certain fuel system components.

REMOVAL

(1) Disconnect the negative battery cable.
(2) Unplug the electrical connector.
(3) Remove the sensor retaining bolts, remove the

sensor (Fig. 5) and O-ring.

INSTALLATION

(1) Inspect boost pressure sensor O-ring for cuts or

abrasions, replace as necessary.

(2) Position the boost pressure sensor above access

hole in the charge air pipe and push down to fit flush
(Fig. 21).

(3) Install the bolts and tighten to 44 lbs. in. (5

N·m) (Fig. 21).

(4) Reconnect the sensor electrical connector (Fig.

21).

(5) Connect negative battery cable

CAMSHAFT POSITION SEN-
SOR

DESCRIPTION

The camshaft position sensor is mounted on the

cylinder head cover toward the rear of the engine.
The camshaft sensor (Fig. 6) utilizes a non contact
method on one segment of the camshaft to record the
camshaft position. When the ECM receives the signal
from this sensor, it can then detect TDC of cylinder
number one. The signal from the camshaft sensor is
only required during engine starting. Injection timing

Fig. 4 BOOST PRESSURE SENSOR

Fig. 5 BOOST PRESSURE AND INLET AIR

TEMPERATURE SENSORS

1 - CHARGE AIR DUCT
2 - INTAKE AIR TEMPERATURE SENSOR
3 - BOOST PRESSURE SENSOR

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is synchronized by means of the camshaft signal and
the crankshaft signal.

OPERATION

On the camshaft sensor’s signal line, a high signal

correspons to a voltage of 0-5V. If the segment
machined into the exhaust camshaft sprocket is posi-
tioned opposite the camshaft sensor, the camshaft
signal is low, approximately 0V. This signal is used
by the engine control module (ECM) for detecting
ignition TDC of cylinder 1 as the engine rotates. If no
signal is supplied by the camshaft position sensor,
the vehicle will not start because cylinder order can
not be detected.

REMOVAL

(1) Disconnect negative battery cable.
(2) Remove engine cover
(3) Disconnect camshaft position sensor electrical

connector (Fig. 7).

(4) Remove retaining bolt and remove sensor (Fig.

7).

INSTALLATION

(1) Install camshaft position sensor and tighten

bolt (Fig. 8).

(2) Reconnect electrical connector (Fig. 8).

Fig. 6 CAMSHAFT POSITION SENSOR

Fig. 7 CAM POSITION SENSOR

1 - WIRING HARNESS CONNECTOR
2 - CAM POSITION SENSOR
3 - O-RING
4 - CYLINDER HEAD COVER

Fig. 8 CAM POSITION SENSOR

1 - WIRING HARNESS CONNECTOR
2 - CAM POSITION SENSOR
3 - O-RING
4 - CYLINDER HEAD COVER

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(3) Install engine cover.
(4) Reconnect negative battery cable.

CRANKSHAFT POSITION SEN-
SOR

DESCRIPTION

The crankshaft position sensor is located opposite

the teeth on the flywheel and uses a non contact
method to record the position of the crankshaft. The
leading edges of each tooth on the flywheel generate
a positive signal in the position sensor, while the
trailing edges generate a negative signal. When the
crankshaft is rotating, an alternating voltage is pro-
duced as a result.

The period of the signal is the time required by the

crankshaft to turn through the gap between two fly-
wheel teeth. The clearance between the crankshaft
position sensor and the teeth of the flywheel is fixed
by the installation.

Two teeth on the flywheel are missing. The result-

ing signal gap is used by the ECM to detect the TDC
position of cylinder number one.

OPERATION

The clearance between the crankshaft position sen-

sor and the flywheel are fixed by the installation
position. Two teeth on the flywheel are missing. The
resulting gap is used by the ECM to detect DTC of
cylinder number one. The crankshaft position is cal-
culated to an accuracy of a fraction of a degree so
that the start and end of injection can occur at
exactly the right moment. The engine speed signal is
also processed by the ECM from the crankshaft sen-
sor. This signal is then transferred to other control
modules over the CAN bus.

If the crankshaft position sensor fails, the ECM

will stop triggering the injectors, the engine will
stall, the engine warning light may or may not illu-
minate, but the engine will not restart.

REMOVAL

(1) Disconnect the negative battery cable.
(2) Unplug the crankshaft wiring harness connec-

tor.

(3) Remove the crankshaft sensor retaining bolt

and remove sensor (Fig. 9).

INSTALLATION

(1) Position the crankshaft position sensor into the

access hole and install retaining bolt.

(2) Tighten the retaining bolt to 80 lbs. in. (9 N·m)

(Fig. 9).

(3) Connect crankshaft position sensor wiring har-

ness connector (Fig. 9).

(4) Connect negative battery cable.

FUEL INJECTOR

DESCRIPTION

FUEL INJECTOR

There are individual fuel injectors for all five cyl-

inders. Each injector nozzle has seven holes. The fuel
injectors are used to spray fuel into the combustion
chamber. Each injector has a six digit alphanumeric
code on the injector top which must be entered into
to ECM using the DRBIII

t (Fig. 10). Specific moving

parts inside the injector are graphite coated to assist
with the lubrication process.

Fig. 9 CRANKSHAFT POSITION SENSOR

1 - ENGINE BLOCK
2 - WIRING HARNESS CONNECTOR
3 - CRANKSHAFT POSITION SENSOR
4 - STARTER SOLENOID

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OPERATION

The injector operation can be subdivided into four

operating states with the engine running and the
high-pressure pump generating pressure:

• Injector closed (with high pressure applied)

• Injector opens (start of injection)

• Injector opened fully

• Injector closes (end of injection)

Injector closed (with high pressure applied)

With the injector closed (at-rest state), the solenoid

valve is not energized and is therefore closed. With
the bleed orifice closed, the valve spring forces the
armature’s ball onto the bleed-orifice seat. The rail’s
high pressure build up in the valve control chamber,
and the same pressure is also present in the nozzle’s
chamber volume. The rail pressure applied at the
control plunger’s end face, together with the force of
the nozzle spring, maintain the nozzle in the closed

Fig. 10 FUEL INJECTOR

1 - FUEL INJECTOR
2 - NOZZLE
3 - FUEL INLET FITTING
4 - ELECTRICAL CONNECTION

Fig. 11 INJECTOR COMPONENTS

1 - INJECTOR CLOSED (AT-REST STATUS)
2 - ELECTRICAL CONNECTION
3 - TRIGGERING ELEMENT (SOLENOID VALVE)
4 - FUEL INLET (HIGH PRESSURE) FROM THE RAIL
5 - VALVE BALL
6 - BLEED ORIFICE
7 - FEED ORIFICE
8 - VALVE CONTROL CHAMBER
9 - VALVE CONTROL PLUNGER
10 - FEED PASSAGE TO THE NOZZLE
11 - NOZZLE NEEDLE

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