2005 MERCEDES-BENZ SPRINTER Service Repair Manual

WARNING: USE EXTREME CAUTION WHEN ENGINE
IS OPERATING. DO NOT PUT YOUR HANDS NEAR
PULLEYS, BELTS, OR FAN. DO NOT WEAR LOOSE
CLOTHES.
(4) Start engine and inspect for leaks (Refer to 14 -
FUEL SYSTEM - DIAGNOSIS AND TESTING).
FUEL TEMPERATURE SENSOR
DESCRIPTION
The fuel temperature sensor is located in the fuel
return line directly down stream of the fuel rail pres-
sure control valve. The sensor measures the temper-
ature of the fuel in the return pipe between the rail
and the pre-heating valve. The sensor ranges from -
40ÉF (- 40C) to 284ÉF (140ÉC). If the engine is cold,
the actual value sent will read ambient temperature.
The value rises after the engine has been started.
OPERATION
An negative temperature coefficient (NTC) resistor
integrated in the fuel temperature sensor alters it's
electrical resistance in line with the fuel temperature
(the resistance drops as the temperature rises). If
fuel temperature has reached 248ÉF and engine
speed is above 2000 rpm, a pumping element of the
high pressure fuel injection pump is switched off and
engine output is reduced.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the sensor wiring harness connector
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION -
WARNING).
(3) Remove the fuel temperature sensor from the
fuel rail (Fig. 17).
INSTALLATION
(1) Clean sealing surfaces.
(2) Install new seal on sensor (Fig. 17).
(3) Screw the sensor into the fuel rail and tighten
to 18 lbs.ft. (25 N´m)(Refer to 14 - FUEL SYSTEM/
FUEL INJECTION - WARNING) . (Fig. 17)
(4) Connect negative battery cable.
INLET AIR TEMPERATURE
SENSOR
DESCRIPTION
The inlet air temperature sensor is located
between the charge air pipe and the charge air dis-
tribution of the cylinders. The inlet air temperature
sensor measures the temperature of the air as it is
supplied to the cylinders and transmits the value to
the ECM. This is required in order to determine the
density of the air being supplied for the combustion
process. The value range is from minus 40ÉF up to
302ÉF (minus 40ÉC to 150ÉC).
OPERATION
The Negative Temperature Coefficient (NTC)
resister located within the inlet air temperature sen-
sor alters it's resistance in line with the charge air
temperature. If the engine is cold, the value equals
ambient temperature. For a temperature of 68ÉF
(20ÉC) the resistance is approximately 6000 ohms.
For a temperature of 104ÉF (40ÉC) the resistance is
approximately 2600 ohms (Fig. 18).
Fig. 17 FUEL TEMPERATURE SENSOR
1 - FUEL RAIL
2 - FUEL TEMPERATURE SENSOR
3 - HARNESS CONNECTOR
4 - SEAL
VAFUEL INJECTION 14 - 29
FUEL PRESSURE SOLENOID (Continued)

REMOVAL
(1) Disconnect the negative battery cable.
(2) Unplug the wiring harness connector at the
inlet air temperature sensor.
(3) Press together the sensor locking arms and
remove the sensor from the charge air pipe (Fig. 19).
INSTALLATION
(1) Position the inlet air temperature sensor above
the charge air pipe access hole.
(2) Press together the sensor locking tabs, seat the
sensor to the pipe and release tabs (Fig. 19).
(3) Connect negative battery cable.
MANIFOLD AIR FLOW (MAF)
SENSOR
DESCRIPTION
The Mass Air Flow (MAF) Sensor is located in the
air intake port between the air filter and the turbo-
charger (Fig. 20). The MAF sensor uses semiconduc-
tor technology throughout, and is used to calculate
the air mass flowing past it per time unit. This mass
is important for determining the exhaust gas recircu-
lation rate. The MAF sensor sends a corresponding
signal to the ECM, which evaluates the signal to
adjust the exhaust gas recirculation valve.
OPERATION
The ECM uses the mass air flow (MAF) sensor to
measure air density. The temperature resistor located
at the front of the MAF sensor measures the temper-
ature of the inlet air. By varying the voltage, the
electronic circuit regulates the temperature of the
heating resistor in the rear so that it is 320É F
(160ÉC) higher than the temperature of the intake
air. The temperature at the heating resistor is mea-
sured by a sensor resistor in-between.
Fig. 18 INLET AIR TEMPERATURE SENSOR
1 - INLET AIR TEMPERATURE SENSOR
2 - PIPE
Fig. 19 INLET AIR TEMPERATURE
1 - INLET AIR TEMPERATURE SENSOR
2 - HARNESS CONNECTOR
3 - CHARGE AIR PIPE
Fig. 20 MASS AIR FLOW (MAF) SENSOR
14 - 30 FUEL INJECTIONVA
INLET AIR TEMPERATURE SENSOR (Continued)

Because the incoming air has a cooling effect, the
greater the amount of air that flows in, then the
higher the voltage of the heating resistor. The heat-
ing resistor is therefore a measure of mass of air
flowing past. If a temperature change occurs as a
result of a increase or reduction of air flow, the ECM
corrects the voltage at the heating resistor until the
temperature difference is again achieved. This con-
trol voltage is use by the ECM as a unit measure for
metered air mass.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Detach the air hose at the Manifold Air Flow
(MAF) sensor
(3) Unplug the MAF wiring harness connector.
(4) Remove the screws retaining the MAF sensor
to the air cleaner housing, and remove MAF sensor.
INSTALLATION
(1) Position the MAF sensor to air cleaner housing
and install the retaining screws (Fig. 21).
(2) Connect the air intake hose to the MAF sensor
and tighten clamp.
(3) connect the MAF wiring harness connector.
(4) Connect negative battery cable.
Fig. 21 MANIFOLD AIR FLOW SENSOR
1 - WIRING HARNESS
2 - AIR INTAKE HOSE
3 - CLAMP
4 - MAF SENSOR
5 - AIR CLEANER HOUSING
VAFUEL INJECTION 14 - 31
MANIFOLD AIR FLOW (MAF) SENSOR (Continued)

STEERING
TABLE OF CONTENTS
page page
STEERING
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - POWER
STEERING SYSTEM....................2COLUMN...............................5
GEAR..................................8
LINKAGE..............................10
PUMP.................................12
STEERING
DESCRIPTION
CAUTION: Mopar ATF+4 Automatic Transmission
fluid or equivalent is to be used in the power steer-
ing system. No other power steering or automatic
transmission fluid is to be used in the system.
Damage may result to the power steering pump and
system if any other fluid is used, and do not over-
fill.
Power steering systems consist of:
²Steering column
²Rack and pinion steering gear
²Belt driven hydraulic steering pump
²Pump pressure and return hoses
²Oil Cooler
OPERATION
The steering column shaft is attached to the gear
pinion. The rotation of the pinion moves the gear
rack from side-to-side. This lateral action of the rack
pushes and pulls the tie rods to change the direction
of the front wheels (Fig. 1).
Power assist is provided by an engine mounted
hydraulic pump which supplies hydraulic fluid pres-
sure to the steering gear.
Fig. 1 STEERING COMPONENTS
1 - POWER STEERING PUMP ASSEMBLY
2 - RESERVOIR
3 - HOSES
4 - TIE ROD ENDS
5 - MOUNTING BOLTS
6 - RACK & PINION
VASTEERING 19 - 1

DIAGNOSIS AND TESTING - POWER STEERING SYSTEM
There is some noise in all power steering systems. One of the most common is a hissing sound evident at a
standstill parking. Or when the steering wheel is at the end of it's travel. Hiss is a high frequency noise similar
to that of a water tap being closed slowly. The noise is present in all valves that have a high velocity fluid passing
through an orifice. There is no relationship between this noise and steering performance.
STEERING NOISE
CONDITION POSSIBLE CAUSES CORRECTION
OBJECTIONAL HISS OR
WHISTLE1. Steering intermediate shaft to dash panel
seal.1. Check and repair seal at dash
panel.
2. Noisy valve in power steering gear. 2. Replace steering gear.
RATTLE OR CLUNK 1. Gear mounting bolts loose. 1. Tighten bolts to specification.
2. Loose or damaged suspension
components.2. Inspect and repair suspension.
3. Internal gear noise. 3. Replace steering gear.
4. Pressure hose in contact with other
components.4. Reposition hose.
5. Loose or damaged intermediate shaft or
column.5. Inspect and repair or replace.
CHIRP OR SQUEAL 1. Loose belt. 1. Adjust or replace.
WHINE OR GROWL 1. Low fluid level. 1. Fill to proper level.
2. Pressure hose in contact with other
components.2. Reposition hose.
3. Internal pump noise. 3. Replace pump.
4. Air in fluid 4. Check for lekas, Evacuate air
from P/S system.
SUCKING AIR SOUND 1. Loose return line clamp. 1. Replace clamp.
2. O-ring missing or damaged on hose
fitting.2. Replace o-ring.
3. Low fluid level. 3. Fill to proper level.
4. Air leak between pump and reservoir. 4. Repair as necessary.
5. Reservoir cap not installed correctly. 5. Install reservoir cap correctly.
SCRUBBING OR
KNOCKING1. Wrong tire size. 1. Verify tire size.
19 - 2 STEERINGVA
STEERING (Continued)

BINDING AND STICKING
CONDITION POSSIBLE CAUSE CORRECTION
DIFFICULT TO TURN WHEEL
STICKS OR BINDS1. Low fluid level. 1. Fill to proper level.
2. Tire pressure. 2. Adjust tire pressure.
3. Steering components (ball
joints/tie rod ends).3 Inspect and repair as necessary.
4. Loose belt. 4. Adjust or replace.
5. Low pump pressure. 5. Pressure test and replace if
necessary.
6. Column shaft coupler binding. 6. Replace coupler.
7. Steering gear worn. 7. Replace gear.
8. Pump seized / Stuck valve 8. Replace pump.
INSUFFICIENT ASST. OR POOR RETURN TO CENTER
CONDITION POSSIBLE CAUSE CORRECTION
HARD TURNING OR MOMENTARY
INCREASE IN TURNING EFFORT1. Tire pressure. 1. Adjust tire pressure.
2. Low fluid level. 2. Fill to proper level.
3. Loose belt. 3. Adjust or replace.
4. Low pump pressure. 4. Pressure test and repair as
necessary.
5. Internal gear leak. 5. Replace gear.
STEERING WHEEL DOES NOT
WANT TO RETURN TO CENTER
POSITION1. Tire pressure. 1. Adjust tire pressure.
2. Wheel alignment. 2. Align front end.
3. Lack of lubrication. 3. Inspect and lubricate suspension
compnents.
4. High friction in steering gear. 4. Replace gear.
VASTEERING 19 - 3
STEERING (Continued)

LOOSE STEERING AND VEHICLE LEAD
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE PLAY IN STEERING
WHEEL1. Worn or loose suspension or
steering components.1. Inspect and repair as necessary.
2. Worn or loose wheel bearings. 2. Inspect and repair or adjust
bearings.
3. Steering gear mounting. 3. Tighten gear mounting bolts to
specification.
4. Gear out of adjustment. 4. Replace gear.
5. Worn or loose steering coupler. 5. Inspect and replace as
necessary.
VEHICLE PULLS OR LEADS TO
ONE SIDE.1. Tire Pressure. 1. Adjust tire pressure.
2. Radial tire lead. 2. Rotate tires.
3. Brakes dragging. 3. Repair as necessary.
4. Wheel alignment. 4. Align front end.
19 - 4 STEERINGVA
STEERING (Continued)