battery MERCEDES-BENZ SPRINTER 2006 Service Manual

(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 IIItscan 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
VAFUEL INJECTION 14 - 33

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
14 - 34 FUEL INJECTIONVA

(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 DRBIIIt(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
VAFUEL INJECTION 14 - 35

INJECTOR CLASSIFICATION PROCEDURE
(1) Turn ignition switch ªONº.
(2) Using a DRB IIItand select ENGINE then
MISCELLANEOUS.
(3) Select LEARN INJECTORS.
(4) Using the up and down arrows, scroll to the
appropriate injector.
(5) Using the right and left arrows, set injector to
proper classification.
(6) Once injectors are classified, cycle ignition to
complete.
CLEANING FUEL INJECTORS
NOTE: Before cleaning the injector recesses, seal
the injector holes in the injector recesses with the
appropriate pin to prevent debris from falling into
the recesses and entering the motor.
(1) Seal the injector holes inside the cylinder head
recesses.
(2) Wipe out injector recesses with a non-woven
cloth, then clean with a cylinder brush.
(3) Clean the bottom of the cylinder recess with a
round brush.
(4) Blow out the recess and clean again with a
non-woven cloth and cover over.
(5) Perform these steps for each injector recess.
NOTE: DO NOT clean the tip of the injector with a
wire brush. Use a non - woven cloth.
(6) Clean injector body with a wire brush.
(7) Clean injector tips with a non-woven cloth.
NOTE: Do Not apply antiseize lubricant to the injec-
tor nozzle area.
(8) Grease injector body with anti seize lubricant.
NOTE: Always replace the seals that seal off the
injectors at the cylinder head to the combustion
chamber and replace the retaining screws.
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.
NOTE: When removing injectors, the seal rings and
retaining stretch bolts must always be replaced.
Coat the injector body with the anti-seize com-pound before installing. Keep lubricant away from
the injector nozzle.
(1) Disconnect negative battery cable.
(2) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(3) Remove the fuel return hose locking clamps at
the injector and remove return hose.
(4) Disconnect the injector electrical connector
(Fig. 13).
NOTE: Counterhold injection lines with wrench
socket at threaded connections of injectors.
(5) Disconnect fuel injector high pressure line (Fig.
13).
(6) Remove fuel injector retaining bolt and tension
claw, then remove the injector and seal (Fig. 13).
NOTE: If injectors are tight, remove with extraction
claw in place of tensioning claw. If extraction claw
contacts cylinder head cover, remove cylinder head
cover. If necessary, remove injectors with threaded
adaptor and discard injector.
(7) Remove injectors (Fig. 13).
(8) Clean injectors and recesses (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION/FUEL INJEC-
TOR - STANDARD PROCEDURE).Fig. 13 FUEL INJECTOR REMOVAL / INSTALLATION
1 - FUEL INJECTOR RETURN LINE
2 - RETAINING CLIP
3 - INJECTOR HIGH PRESSURE LINE
4 - INJECTOR SEAL
5 - FUEL INJECTOR
6 - TENSIONING CLAW
7 - SPECIAL TOOLS #8938 AND # 8937
14 - 38 FUEL INJECTIONVA

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.
NOTE: When removing injectors, the seal rings and
retaining stretch bolts must always be replaced.
Coat the injector body with the anti-seize com-
pound before installing. Keep lubricant away from
the injector nozzle.
(1) Clean injectors and recesses (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION/FUEL INJEC-
TOR - STANDARD PROCEDURE).
(2) Coat injector body with anti seize lubricant
then install injectors with new seals.
(3) Install tensioning claws with new screws at
injectors. Tighten screws in two stages, 7 N´m (62
lbs. in.) then 90É (Fig. 13).
NOTE: If locking clamp has been pulled off at injec-
tor, the locking clamp must be replaced.
(4) Position fuel return line at injectors and secure
locking clamps (Fig. 13).
NOTE: Counterhold injection lines with wrench
socket at threaded connections of injectors. DO
NOT over tighten.
(5) Install high pressure injection lines (Refer to
14 - FUEL SYSTEM/FUEL DELIVERY/FUEL LINES
- INSTALLATION).
(6) Reconnect injector electrical connectors (Fig.
13).
(7) Connect negative battery cable.
NOTE: Fuel Injectors have different flow rates.
When injectors are removed, re-enter all injector six
digit codes.
(8) Program all injector codes into the ECM using
the scan tool.
(9) Start engine, allow to run, turn engine off and
inspect for leaks (Refer to 14 - FUEL SYSTEM -
WARNING).
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.(10) Install engine cover (Refer to 9 - ENGINE -
INSTALLATION)..
FUEL PRESSURE SENSOR
DESCRIPTION
The fuel rail pressure sensor measures the current
fuel rail pressure and supplies an appropriate voltage
signal to the ECM. The non-constant fuel system
pressure influences the position of the internal dia-
phragm. This results in a variation in the electrical
resistance which is analyzed by the ECM.
OPERATION
The fuel rail pressure sensor measures the current
fuel rail pressure and sends a voltage signal to the
ECM. The ECM then actuates the fuel rail pressure
control valve until the desired rail pressure is
achieved.
REMOVAL
(1) (Refer to 14 - FUEL SYSTEM/FUEL INJEC-
TION - WARNING) Disconnect the negative battery
cable.
(2) Remove the mixing housing.
(3) Unplug the sensor (Fig. 14).
(4) Counter-hold the threaded connection at the
fuel rail and unscrew the sensor (Fig. 14).
Fig. 14 FUEL RAIL PRESSURE SENSOR
1 - WIRING CONNECTOR
2 - FUEL RAIL PRESSURE SENSOR
3 - SEALING RING
4 - FUEL RAIL
VAFUEL INJECTION 14 - 39

INSTALLATION
(1) (Refer to 14 - FUEL SYSTEM/FUEL INJEC-
TION - WARNING) Install the sealing ring on to the
sensor (Fig. 14).
(2) Screw the sensor in to the fuel rail. Counter-
hold the threaded connection and tighten the sensor
to 18 lbs. ft. (25 N´m.) (Fig. 14).
(3) Connect the wiring harness to the sensor.
(4) Install the mixing housing.
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) Connect negative battery cable.
FUEL PRESSURE SOLENOID
DESCRIPTION
The fuel pressure solenoid is attached to the rear
of the fuel rail. A sealing metal disc seals the valve to
the rail. The seal is not serviceable and looses it's
sealing properties upon removal of the solenoid.
Therefore, the solenoid must be replaced when ever
it is removed from the rail. The solenoid controls and
maintains the rail pressure constant along with a
control current transmitted by the engine control
module (ECM) (Fig. 15).
OPERATION
High pressure which is present in the fuel rail
flows to the ball seat of the pressure solenoid (Fig.
16). The specified pressure required by the system is
built up in the rail by the fuel pressure solenoid
building up a magnetic force which corresponds to
this specific pressure by means of a control current
from the electronic control module (ECM) (Fig. 16).
This magnetic force equals a certain outlet cross sec-
tion at the ball seat of the valve. The rail pressure is
altered as a result of the quantity of fuel which flows
off (Fig. 16). The current fuel pressure is signaled by
the fuel rail pressure sensor to the engine control
module (ECM). The controlled fuel flows back along
the return fuel line, into the tank.
In a de-energized state, the fuel pressure solenoid
is closed as the spring force presses the ball into the
ball seat (Fig. 16). When driving, the fuel pressure
solenoid is constantly open (Fig. 16). When engine is
started, the fuel pressure solenoid is held closed by
magnetic force (Fig. 16). When driving, the pressure
of the fluid counteracts the magnetic force of the coil
and the slight spring force (Fig. 16).
Fig. 15 FUEL PRESSURE SOLENOID
1 - FUEL PRESSURE SENSOR
2 - FUEL RAIL
3 - FUEL PRESSURE SOLENOID
Fig. 16 FUEL PRESSURE SOLENOID OPERATION
1 - BALL SEAT
2 - SPRING FORCE
3 - MAGNETIC FORCE
4 - COIL
5 - FUEL PRESSURE SOLENOID
6 - HIGH PRESSURE SUPPLY
14 - 40 FUEL INJECTIONVA

STANDARD PROCEDURE - FUEL PRESSURE
SOLENOID TEST
(1) Disconnect the large fuel rail return hose at
the banjo fitting and clamp it off. Attach a jumper
hose to the banjo fitting and direct the hose into a
test vial. Crank the engine for 10 seconds (Fig. 17).
If return fuel is present in the test vial, replace the
fuel pressure solenoid.
REMOVAL
Review the high pressure fuel system warning before
beginning repair (Refer to 14 - FUEL SYSTEM - WARNING)
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.
(2) Remove fuel rail (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION/FUEL INJECTOR - REMOVAL).
(3) Clamp fuel rail securely in vise with protective
jaws.
NOTE: Once removed, the solenoid must always be
replaced.
(4) Counterhold and unscrew the fuel pressure
solenoid and discard the sealing ring (Fig. 18).
INSTALLATION
Review the high pressure fuel system warning before
beginning repair (Refer to 14 - FUEL SYSTEM - WARNING)
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: There is a special tightening procedure
for the fuel rail solenoid that must be followed
along with the proper use of a torque wrench.
Therefore the fuel rail must be removed before
installing the fuel pressure solenoid. Attention must
be paid to the sealing ring before assembly. If the
sealing ring is damaged when assembling, this
could result in a not so visible leak.
NOTE: Observe the alignment of the pressure sole-
noid. The electrical connection must point in the
same direction as the connection of the injection
line at the fuel rail.
(1) Screw the fuel pressure solenoid with new seal-
ing disc to the fuel rail until hand tight (Fig. 18).
(2) Tighten the fuel rail solenoid as follows :
Fig. 17 CHECKING FUEL RAIL PRESSURE
SOLENOID LEAKAGE
1 - CLAMP RUBBER FUEL RETURN HOSES
2 - ATTACH SEPARATE RUBBER FUEL HOSE
3 - CONTAINER TO MEASURE FUEL LEAKAGE
4 - DISCONNECT RUBBER RETURN HOSE
Fig. 18 FUEL PRESSURE SOLENOID
1 - FUEL PRESSURE SOLENOID
2 - METAL SEALING DISC
3 - FUEL RAIL
4 - VISE
VAFUEL INJECTION 14 - 41

²Tighten the nut to 60 N´m (44 ft. lbs.)
²Loosen the nut 90 degrees.
²Retighten the nut to 80 N´m (59 ft. lbs.).
(3) Install fuel rail (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION/FUEL INJECTOR - INSTALLA-
TION).
(4) Connect negative battery cable.
(5) Start engine, allow to warm, turn engine off
and inspect for leaks (Refer to 14 - FUEL SYSTEM -
DIAGNOSIS AND TESTING).
FUEL TEMPERATURE SENSOR
DESCRIPTION
The fuel temperature sensor is integrated in the
high pressure fuel pump next to the fuel quantity
valve. The sensor detects the temperature of the fuel
and supplies that information to the ECM. The sen-
sor 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). The
ECM uses this reading to calculate optimum engine
performance under all driving conditions. If the fuel
is to warm, the rail pressure in the system is low-
ered. The controller quantity of the pressure regulat-
ing valve is reduced and the fuel temperature is
lowered.
REMOVAL
NOTE: Capture and properly store all fluid seepage
in appropriately marked containers.
(1) Disconnect the negative battery cable.
(2) Remove the fuel temperature sensor from the
high pressure pump (Fig. 19).
INSTALLATION
(1) Clean sealing surfaces.
(2) Install new seal on sensor.
(3) Screw the sensor into the high pressure pump
and tighten to 18 lbs.ft. (25 N´m) (Fig. 19)
(4) Connect negative battery cable.
(5) Start engine, allow to warm, shut engine off
and inspect for leaks (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION - WARNING).
INTAKE AIR TEMPERATURE
SENSOR
DESCRIPTION
The intake air temperature sensor is located
between the charge air pipe and the charge air dis-
tribution of the cylinders. The intake 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).
Fig. 19 HIGH PRESSURE FUEL PUMP
1 - HIGH PRESSURE PUMP
2 - FUEL SUPPY TO FUEL RAIL
3 - FUEL SUPPLY LINE
4 - FUEL RETURN LINE
5 - FUEL TEMPERATURE SENSOR
6 - FUEL QUANTITY CONTROL VALVE
7 - OIL LEVEL INDICATOR
8 - VACUUM PUMP
14 - 42 FUEL INJECTIONVA

OPERATION
The Negative Temperature Coefficient (NTC)
resister located within the intake air temperature
sensor 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 resis-
tance is approximately 3300 ohms (Fig. 20).
REMOVAL
(1) Disconnect the negative battery cable.
(2) Unplug the wiring harness connector at the
intake air temperature sensor.
(3) Press together the sensor locking arms and
remove the sensor from the charge air pipe (Fig.
21).
INSTALLATION
(1) Position the intake 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. 21).
(3) Connect negative battery cable.
INTAKE AIR PRESSURE SEN-
SOR
DESCRIPTION
An absolute pressure sensor is mounted to the air
cleaner housing. The sensor is used by the ECM to
adjust for changes in altitude and for air intake
obstructions due to a clogging air cleaner.
OPERATION
The ECM uses the intake air pressure sensor to
monitor the intake pressure. Monitoring this pres-
sure allows better control of the variable geometry
turbocharger to suit the driving environment and
preserve turbocharger durability.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the sensor electrical connector.
(3) Remove the air intake pressure sensor.
Fig. 20 INLET AIR TEMPERATURE SENSOR
1 - INTAKE AIR TEMPERATURE SENSOR
2 - PIPE
Fig. 21 BOOST PRESSURE AND INLET AIR
TEMPERATURE SENSORS
1 - CHARGE AIR DUCT
2 - INTAKE AIR TEMPERATURE SENSOR
3 - BOOST PRESSURE SENSOR
VAFUEL INJECTION 14 - 43

INSTALLATION
(1) Positon the pressure sensor in the air cleaner
cover and install the fasteners (Fig. 22).
(2) Connect the electrical connector (Fig. 22).
(3) Connect the 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. 23). 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.
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 sen-
sor.
Fig. 22 AIR CLEANER HOUSING
1 - AIR FLOW SENSOR
2 - GASKET
3 - AIR INTAKE HOSE
4 - AIR CLEANER HOUSING
5 - AIR CLEANER ELEMENT
6 - AIR INTAKE PRESSURE SENSOR
7 - AIR CLEANER HOUSING COVER
Fig. 23 MASS AIR FLOW (MAF) SENSOR
14 - 44 FUEL INJECTIONVA