fuel pressure MERCEDES-BENZ SPRINTER 2005 Service Repair Manual

MAINTENANCE - WITH ASSYST MAINTENANCE
COMPUTER
ASSYST provides information on the best possible
timing for maintenance work.
NOTE: The engine manufacturer strongly recom-
mends the use of synthetic engine oils, such as
TMobil 1 SAE 0W-40.
When the next maintenance service is due, this
will be indicated in the multi-function display with
the wrench icon symbol displayed in km/miles or
days.
²One wrench icon showing indicates Oil Service
is necessary.
²Two wrench icons showing indicates Mainte-
nance Service is necessary ± displayed in km/miles or
days.
If the display shows the number of days, a clock
symbol will also appear in the multi-function display.
You should have the maintenance performed
within the stated period/distance.
The service indicator should be reset after an oil
service and/or maintenance service has been per-
formed.
REGULAR CHECK-UPS
To maintain the safe operation of the vehicle, it is
recommended that the following tasks be performed
on a regular basis (i.e. weekly or whenever the vehi-
cle is refueled). Check:
²Engine oil level
²Brake system, clutch mechanism ± fluid level
²Battery ± acid level
²Windshield washer system and headlamp clean-
ing system ± fluid level
²Mechanical assemblies (e. g. engine, transmis-
sion, etc.) ± check for leaks
²Condition of tires and tires pressures
²All exterior lights
SPECIAL MAINTENANCE REQUIREMENTS
If bodies built by manufacturers other than
DaimlerChrysler Corporation are fitted to the vehi-
cle, the maintenance requirements and lubrication
intervals specified by the body manufacturer must be
adhered to, in addition to all standard maintenance
requirements.
Brake Fluid
Only use brake fluids approved by the manufac-
turer (DOT 4 plus).
Coolant
Corrosion inhibitor/antifreeze concentration in the
coolant should be checked before the onset of winter
(once year in countries with high prevailing temper-
atures).Replace the coolant every five years or 100,000
miles.
Dust Filter for Heating/Ventilation Replace-
ment
The dust filter and the tailgate interior filter are to
be renewed during routine maintenance service. If
operating conditions are dusty, these filters should be
renewed more frequently.
ENGINE OIL CHANGE AND FILTER REPLACEMENT
At the minimum, change the engine oil and oil fil-
ter once a year ± even if the vehicle mileage per year
is extremely low. For standard oil service schedules
refer to the chapter oil service and maintenance ser-
vice.
Once a Year
Select the viscosity of the engine oil (SAE classes)
according to the outside air temperature.
Only use engine oil approved by DaimlerChrysler
Corporation if following the ASSYST system guide-
lines.
If the fuel used has a sulphur content exceeding
0.05% by weight, the service intervals should be split
in half.
SCOPE OF WORK FOR MAINTENANCE SERVICE
Oil Service
²Engine:
Oil change and filter replacement
Check fluid levels of the following system,
refill as necessary.
²If fluid is lost, trace and eliminate cause ± as a
separate order.
²Power-assisted steering
Lubrication work:
²Trailer tow hitch (original equipment)
Maintenance
²ASSYST maintenance computer reset
Function check
²Signalling system, warning and indicator lamps
²Headlamps, exterior lighting
²Windshield wipers, windshield washer system
Check for leaks and damage.
²Check for abrasion points and ensure that lines
are correctly routed!
²All lines and hoses, sensor cables
²Rubber boots on front axle drive shafts, rubber
boots on front axle suspension ball joints, shock
absorbers
Check fluid levels for the following systems,
correct as necessary.
NOTE: Should there be a loss of fluid which cannot
be explained by regular use, trace and eliminate the
cause.
0 - 8 LUBRICATION & MAINTENANCEVA
MAINTENANCE SCHEDULES (Continued)

²Engine cooling system. Check corrosion inhibi-
tor/antifreeze, refill as necessary.
²Hydraulic brake system
²Battery
²Windshield washer system
Engine
²Fuel filter renewal
²Air cleaner with maintenance indicator:
²Check degree of contamination.
²Air cleaner filter element renewed as necessary.
Chassis and body
²Trailer coupling:
Check operation, play and retaining fixtures
²Secondary rubber springs:
Visual check
²Tire pressures:
Correct as necessary, including spare tire
²Check thickness of brake pads
²Brake test
²Check condition of steering mechanism
²Heating/ventilation dust filter renewal
ADDITIONAL MAINTENANCE WORK
Automatic transmission once only at 80,000
miles/128000 km
Oil and filter change
During every second maintenance service
Air cleaner without maintenance indicator:
Air cleaner filter element renewal
Check poly-V-belt for wear and signs of damage
During every 6th maintenance service
Rear axle
ADDITIONAL MAINTENANCE WORK AFTER YEARS
Every 3 years
Air cleaner filter element renewal (note installa-
tion date)
Every 5 years or 100,000 miles
Coolant renewal
Note coolant composition
INTERNATIONAL SYMBOLS
DESCRIPTION
DaimlerChrysler Corporation uses international
symbols to identify engine compartment lubricant
and fluid inspection and fill locations (Fig. 3).
Fig. 3 INTERNATIONAL SYMBOLS
VALUBRICATION & MAINTENANCE 0 - 9
MAINTENANCE SCHEDULES (Continued)

NOTE: Capture any residual coolant that may flow.
(5) Remove coolant temperature sensor (Fig. 7).
INSTALLATION
WARNING: RISK OF INJURY TO SKIN AND EYES
FROM SCALDING WITH HOT COOLANT. RISK OF
POISONING FROM SWALLOWING COOLANT. DO
NOT OPEN COOLING SYSTEM UNLESS COOLANT
TEMPERATURE IS BELOW 90ÉC (194ÉF). OPEN CAP
SLOWLY TO RELEASE PRESSURE. STORE COOL-
ANT IN SUITABLE AND APPROPRIATELY MARKED
CONTAINER. WEAR PROTECTIVE GLOVES,
CLOTHES AND EYE WEAR.
(1) Position and install coolant temperature sensor
(Fig. 7).
(2) Connect coolant temperature sensor electrical
connector (Fig. 7).
(3) Refill coolant system to proper level with
proper mixture of coolant (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).(4) Install engine cover (Refer to 9 - ENGINE -
INSTALLATION).
(5) Connect negative battery cable.
WARNING: USE EXTREME CAUTION WHEN ENGINE
IS OPERATING. DO NOT STAND IN A DIRECT LINE
WITH FAN. DO NOT PUT YOUR HANDS NEAR PUL-
LEYS, BELTS OR FAN. DO NOT WEAR LOOSE
CLOTHES.
(6) Start engine and inspect for leaks.
ENGINE COOLANT
THERMOSTAT
REMOVAL
WARNING: RISK OF INJURY TO SKIN AND EYES
FROM SCALDING WITH HOT COOLANT. RISK OF
POISONING FROM SWALLOWING COOLANT. DO
NOT OPEN COOLING SYSTEM UNLESS COOLANT
TEMPERATURE IS BELOW 90ÉC (194ÉF). OPEN CAP
SLOWLY TO RELEASE PRESSURE. STORE COOL-
ANT IN SUITABLE AND APPROPRIATELY MARKED
CONTAINER. WEAR PROTECTIVE GLOVES,
CLOTHES AND EYE WEAR.
NOTE: Inspect condition of all clamps and hoses,
replace as necessary.
(1) Disconnect negative battery cable.
(2) Drain engine coolant (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(3) Unplug connector, pull off locking element and
pull out coolant temperature sensor.
(4) Detach air intake hose at charge air distribu-
tion pipe.
(5) Detach coolant hoses at thermostat housing.
(6) Remove bracket for fuel line.
(7) Unscrew cap at oil filter housing.
(8) Remove thermostat housing (Fig. 8).
(9) Clean all sealing surfaces.
Fig. 7 ENGINE COOLANT TEMPERATURE SENSOR
1 - RETAINING CLAMP
2 - ENGINE COOLANT TEMPERATURE SENSOR
VAENGINE 7 - 15
ENGINE COOLANT TEMP SENSOR (Continued)

INSTALLATION
(1) Clean all sealing surfaces.
(2) Position and install thermostat housing with
new gasket (Fig. 8). Tighten bolts to 9N´m (80
lbs.in.).
NOTE: Inspect condition of all clamps and hoses,
replace as necessary.
(3) Install cap at oil filter housing.
(4) Connect coolant hoses and vent hose (Fig. 8).
(5) Install bracket for fuel line (Fig. 8).
(6) Attach air intake hose at charge air distribu-
tion pipe.
(7) Close coolant drain.
(8) Connect negative battery cable.
(9) Fill coolant system to proper level with appro-
priate coolant mixture (Refer to 7 - COOLING/EN-
GINE/COOLANT - STANDARD PROCEDURE).
WARNING: USE EXTREME CAUTION WHEN ENGINE
IS OPERATING. DO NOT STAND IN DIRECT LINE
WITH FAN. DO NOT PUT YOUR HANDS NEAR PUL-
LEYS, BELTS OR FAN. DO NOT WEAR LOOSE
CLOTHES.
(10) Start engine and inspect for leaks.
FAN DRIVE VISCOUS CLUTCH
REMOVAL
(1) For fan drive viscous clutch removal refer to
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
INSTALLATION
(1) For fan drive viscous clutch installation refer to
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
RADIATOR
REMOVAL
WARNING: RISK OF INJURY TO SKIN AND EYES
FROM SCALDING WITH HOT COOLANT. RISK OF
POISONING FROM SWALLOWING COOLANT. DO
NOT OPEN COOLING SYSTEM UNLESS COOLANT
TEMPERATURE IS BELOW 90ÉC (194ÉF). OPEN CAP
SLOWLY TO RELEASE PRESSURE. STORE COOL-
ANT IN SUITABLE AND APPROPRIATELY MARKED
CONTAINER. WEAR PROTECTIVE GLOVES,
CLOTHES AND EYE WEAR.
NOTE: Capture all residual fluid spillage and store
in suitably marked containers. Inspect condition of
all clamps and hoses, replace as necessary.
(1) Drain coolant from radiator only(Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE).
(2) Remove headlamp.
(3) Remove front cross member together with front
grille.
(4) Remove front bumper.
(5) Evacuate air conditioning.
(6) Remove A/C condenser.
(7) Detach charge air hose at turbocharger (Fig. 9).
(8) Detach charge air hose at air intake pipe (Fig.
9).
(9) Detach air intake pipe at the body (Fig. 9).
(10) Detach coolant hoses at the coolant reservoir
(Fig. 9).
(11) Unplug wiring connector at coolant level sen-
sor (Fig. 9).
(12) Drain steering gear oil from reservoir of
power steering pump.
(13) Detach the hydraulic oil hose at reservoir of
power steering pump.
(14) Detach the hydraulic oil hose at hydraulic oil
line.
Fig. 8 THERMOSTAT HOUSING ASSEMBLY
1 - O-RING
2 - CLAMP
3 - COOLANT TEMPERATURE SENSOR
4 - FUEL LINE W/BRACKET
5 - THERMOSTAT HOUSING ASSEMBLY
6 - COOLANT HOSE
7 - CLAMP
8 - COOLANT HOSE
9 - GASKET
7 - 16 ENGINEVA
ENGINE COOLANT THERMOSTAT (Continued)

DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP
Remove cap from radiator. Be sure that sealing
surfaces are clean. Moisten rubber gasket with water
and install the cap on pressure tester (tool 7700 or
an equivalent) (Fig. 12).
Operate the tester pump and observe the gauge
pointer at its highest point. The cap release pressure
should be 124 to 145 kPa (18 to 21 psi). The cap is
satisfactory when the pressure holds steady. It is also
good if it holds pressure within the 124 to 145 kPa
(18 to 21 psi) range for 30 seconds or more. If the
pointer drops quickly, replace the cap.CAUTION: Radiator pressure testing tools are very
sensitive to small air leaks, which will not cause
cooling system problems. A pressure cap that does
not have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to tool. Turn tool upside
down and recheck pressure cap to confirm that cap
needs replacement.
WATER PUMP
REMOVAL
WARNING: RISK OF INJURY TO SKIN AND EYES
FROM SCALDING WITH HOT COOLANT. RISK OF
POISONING FROM SWALLOWING COOLANT. DO
NOT OPEN COOLING SYSTEM UNLESS COOLANT
TEMPERATURE IS BELOW 90ÉC (194ÉF). OPEN CAP
SLOWLY TO RELEASE PRESSURE. STORE COOL-
ANT IN SUITABLE AND APPROPRIATELY MARKED
CONTAINER. WEAR PROTECTIVE GLOVES,
CLOTHES AND EYE WEAR.
NOTE: Inspect condition of all clamps and hoses,
replace as necessary.
(1) Disconnect the negative battery cable.
(2) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(3) Remove viscous fan clutch.
(4) Detach fuel lines from the brackets at the
water pump.
(5) Detach the coolant hoses at the water pump
(Fig. 13).
Fig. 12 Pressure Testing Radiator Pressure Cap -
Typical
1 - PRESSURE CAP
2 - TYPICAL COOLING SYSTEM PRESSURE TESTER
VAENGINE 7 - 19
RADIATOR PRESSURE CAP (Continued)

(2) Connect the wire harness connectors to the
central timer module.
(3) Install the screws that secure the central timer
module. Tighten the screws securely.
(4) Route the seat belt latch wire lead through the
hole in the closeout panel and position the panel
beneath the driver seat cushion
(5) Install the screws that secure the closeout
panel beneath the driver seat cushion. Tighten the
screws securely.
(6) Connect the wire harness connector to the seat
belt latch connector.
(7) Slide the driver seat to back to its original posi-
tion.
(8) Reconnect the negative battery cable.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to
the Hydraulic Control Unit (HCU) and operates the
ABS system.
REMOVAL
(1) Remove the negative battery cable from the
battery.
(2) Pull up on the CAB harness connector release
and remove connector.
(3) Remove the CAB mounting bolts.
(4) Remove the CAB from the HCU.
INSTALLATION
(1) Install CAB to the HCU.
(2) Install mounting bolts. Tighten to 2 N´m (16 in.
lbs.).
(3) Install the wiring harness connector to the
CAB and push down on the release to secure the con-
nector.
(4) Install negative battery cable to the battery.
ENGINE CONTROL MODULE
DESCRIPTION
The electronic control module (ECM) is mounted to
the left lower dash panel and consists of an electronic
printed circuit board which is designed as a multi-
layer board assembly fitted on both sides. The rout-
ing of the five wiring harness connectors at the ECM
connectors are split into interfering cables and sensi-
tive cables in order to achieve improved electromag-
netic compatibility. The ECM stores engine specific
data, monitors the connected sensor and analyzes
their measurement (Fig. 2).
Its task consists in controlling the following sys-
tems in line with the analysis of the input signals:
²Fuel Supply System
²Injected Quantity Control
²Emission Control System
²Charge Pressure Control
²Cruise Control
²A/C Compressor Shut-Off
²Pre-Heating Output Relay for the Glow Plugs
²Vehicle Theft
²Air Bag
²Monitors inputs/outputs, checks plausibility and
stores faults
²Share information with other control modules
²Diagnosis
If a sensor should fail, provided the fault is not
serious, the ECM will continue to operate the engine
in Limp-Home Mode (emergency mode) using a
default value for the missing signal. The ECM
ensures that continuing to operate the engine will
not cause damage or effect safety,otherwise a Engine
shut-off process will be carried out.Fig. 1 Central Timer Module
1 - DRIVER SEAT
2 - WIRE HARNESS CONNECTOR
3 - SCREW (2)
4 - CLOSEOUT PANEL
5 - CENTRAL TIMER MODULE
6 - WIRE HARNESS CONNECTOR (2)
7 - SCREW (2)
VAELECTRONIC CONTROL MODULES 8E - 3
CENTRAL TIMER MODULE (Continued)

REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the ECM harness connectors (5)
(Fig. 3).
(3) Grasp ECM and pull down firmly to release
ECM from the retaining bracket tensioning springs
(Fig. 3).
INSTALLATION
NOTE: THE ECM MUST BE PROGRAMMED TO SUP-
PORT THE VEHICLE OPTIONS PACKAGE.
(1) Position the ECM into the guide of the retain-
ing bracket (Fig. 3).
(2) Carefully push the ECM in to the bracket until
the bracket tensioning springs engage (Fig. 3).
(3) Connect the ECM wiring harness connectors
(5) (Fig. 3).
(4) Connect negative battery cable.
Fig. 2 ECM
1 - A/C PUSH BUTTON CONTROL 12 - MASS AIR FLOW SENSOR
2 - ECM 13 - CRANKSHAFT POSITION SENSOR
3 - INSTRUMENT CLUSTER 14 - OIL LEVEL, OIL TEMPERATURE AND OIL QUALITY SENSOR
4 - ABS/ASR CONTROLLER 15 - LOW FUEL PRESSURE SENSOR
5 - ANTI-THEFT CONTROLLER 16 - COOLANT TEMPERATURE SENSOR
6 - AIR BAG CONTROLLER 17 - FUEL RAIL PRESSURE SENSOR
7 - IGNITION CYLINDER TRANSCEIVER RING 18 - CAMSHAFT POSITION SENSOR
8 - GLOW PLUG RELAY 19 - CHARGE AIR PRESSURE SENSOR
9 - INTAKE AIR TEMPERATURE SENSOR 20 - FUEL TEMPERATURE SENSOR
10 - KICK DOWN SWITCH 21 - WATER IN FUEL SENSOR
11 - ACCELERATOR PEDAL SENSOR
8E - 4 ELECTRONIC CONTROL MODULESVA
ENGINE CONTROL MODULE (Continued)

²Low and High ATF Temperature.
Upshift
To :1-2 2-3 3-4 4-5
Activated
By
Solenoid:1-2/4-5 2-3 3-4 1-2/4-5
Shift
Point (at
35.2% of
throttle)17.8
km/h
(11.6
mph)32.1
km/h
(19.95
mph)67.5
km/h
(41.94
mph)73.8
km/h
(45.86
mph)
Downshift
From:5-4 4-3 3-2 2-1
Activated
By
Solenoid:1-2/4-5 3-4 2-3 1-2/4-5
Shift
Point55.7
km/h
(34.61
mph)40.5
km/h
(25.17
mph)24.4
km/h
(15.16
mph)15.1
km/h
(9.38
mph)
DOWNSHIFT SAFETY
Selector lever downshifts are not performed if inad-
missible high engine rpm is sensed.
ADAPTATION
To equalize tolerances and wear, an automatic
adaptation takes place for:
²Shift Time.
²Clutch Filling Time.
²Clutch Filling Pressure.
²Torque Converter Lock-Up Control.
Adaptation data may be stored permanently and to
some extent, can be diagnosed.
Driving Style Adaptation
The shift point is modified in steps based on the
information from the inputs. The control module
looks at inputs such as:
²vehicle acceleration and deceleration (calculated
by the TCM).
²rate of change as well as the position of the
throttle pedal (fuel injection information from the
ECM).
²lateral acceleration (calculated by the TCM).
²gear change frequency (how often the shift
occurs).
Based on how aggressive the driver is, the TCM
moves up the shift so that the present gear is held a
little longer before the next upshift. If the driving
style is still aggressive, the shift point is modified up
to ten steps. If the driving returns to normal, thenthe shift point modification also returns to the base
position.
This adaptation has no memory. The adaptation to
driving style is nothing more than a shift point mod-
ification meant to assist an aggressive driver. The
shift points are adjusted for the moment and return
to base position as soon as the inputs are controlled
in a more rational manner.
Shift Time Adaptation (Shift Overlap Adaptation, Working
Pressure)
Shift time adaptation is the ability of the TCM to
electronically alter the time it takes to go from one
gear to another. Shift time is defined as the time it
takes to disengage one shift member while another is
being applied. Shift time adaptation is divided into
four categories:
33. Accelerating upshift, which is an upshift under
a load. For shift time adaptation for the 1-2 upshift
to take place, the transmission must shift from 1st to
2nd in six different engine load ranges vs. transmis-
sion output speed ranges.
34. Decelerating upshift, which is an upshift under
no load. This shift is a rolling upshift and is accom-
plished by letting the vehicle roll into the next gear.
35. Accelerating downshift, which is a downshift
under load. This shift can be initiated by the throttle,
with or without kickdown. The shift selector can also
be used.
36. Decelerating downshift, which is accomplished
by coasting down. As the speed of the vehicle
decreases, the transmission downshifts.
Fill Pressure Adaptation (Apply Pressure Adaptation,
Modulating Pressure)
Fill pressure adaptation is the ability of the TCM
to modify the pressure used to engage a shift mem-
ber. The value of this pressure determines how firm
the shift will be.
²If too much pressure is used, the shift will be
hard.
²If too little pressure is used, the transmission
may slip.
The pressure adjustment is needed to compensate
for the tolerances of the shift pressure solenoid valve.
The amount the solenoid valve opens as well as how
quickly the valve can move, has an effect on the pres-
sure. The return spring for the shift member pro-
vides a resistance that must be overcome by the
pressure in order for shift member to apply. These
return springs have slightly different values. This
also affects the application pressure and is compen-
sated for by fill pressure adaptation.
Fill Time Adaptation (Engagement Time Adaptation)
Fill time is the time it takes to fill the piston cav-
ity and take up any clearances for a friction element
VAELECTRONIC CONTROL MODULES 8E - 7
TRANSMISSION CONTROL MODULE (Continued)

ENGINE TEMPERATURE
GAUGE
DESCRIPTION
An engine coolant temperature gauge is standard
equipment on all instrument clusters. The engine
coolant temperature gauge is located in the upper
right corner of the instrument cluster, to the right of
the speedometer. The engine coolant temperature
gauge consists of a movable gauge needle or pointer
controlled by the instrument cluster circuitry and a
fixed 45 degree scale on the cluster overlay that
reads left-to-right from 120É C to 40É C for Canadian
vehicles, or from 250É F to 110É F for United States
vehicles. An International Control and Display Sym-
bol icon for ªEngine Coolant Temperatureº is located
on the cluster overlay, directly below the high end of
the scale. Just to the right of the icon, the nomencla-
ture ªÉCº or ªÉFº confirms the unit of measure for the
gauge readings.
The engine coolant temperature gauge graphics are
white against a black field, except for a single red
graduation at the far left (high) end of the gauge
scale, making them clearly visible within the instru-
ment cluster in daylight. When illuminated from
behind by the panel lamps dimmer controlled cluster
illumination lighting with the exterior lamps turned
On, the white graphics appear amber and the red
graphics appear red. The orange gauge needle is
internally illuminated. Gauge illumination is pro-
vided by Light Emitting Diode (LED) units soldered
onto the instrument cluster electronic circuit board.
The engine coolant temperature gauge is serviced as
a unit with the instrument cluster.
OPERATION
The engine coolant temperature gauge gives an
indication to the vehicle operator of the engine cool-
ant temperature. This gauge is controlled by the
instrument cluster circuit board based upon cluster
programming and electronic messages received by
the cluster from the Engine Control Module (ECM)
over the Controller Area Network (CAN) data bus.
The engine coolant temperature gauge is an air core
magnetic unit that receives battery current on the
instrument cluster electronic circuit board when the
instrument cluster detects that the ignition switch is
in the On position. The cluster is programmed to
move the gauge needle back to the low end of the
scale after the ignition switch is turned to the Off
position. The instrument cluster circuitry controls
the gauge needle position and provides the following
features:
²Engine Temperature Normal Message- Each
time the cluster receives a message from the ECMindicating the engine coolant temperature is within
the normal operating range [up to about 120É C (250É
F), the gauge needle is moved to the actual relative
temperature position on the gauge scale.
²Engine Temperature High Message- Each
time the cluster receives a message from the ECM
indicating the engine coolant temperature is high
[above about 120É C (250É F) the gauge needle is
moved into the red warning zone on the gauge scale.
The ECM continually monitors the engine coolant
temperature sensor to determine the engine operat-
ing temperature. The ECM then sends the proper
engine coolant temperature messages to the instru-
ment cluster. If the instrument cluster moves the
engine coolant temperature gauge needle to red area
of the gauge scale, it may indicate that the engine or
the engine cooling system require service. For proper
diagnosis of the engine coolant temperature sensor,
the ECM, the CAN data bus, the electronic message
inputs to the instrument cluster, or the instrument
cluster circuitry that controls the engine coolant tem-
perature gauge, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
FUEL FILTER CLOGGED
INDICATOR
DESCRIPTION
A fuel filter clogged indicator is standard equip-
ment on all instrument clusters. The fuel filter
clogged indicator is located near the left edge of the
instrument cluster, next to the tachometer. The fuel
filter clogged indicator consists of the International
Control and Display Symbol icon for ªFuel Filterº
imprinted within a rectangular cutout in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents the indicator from
being clearly visible when it is not illuminated. An
amber Light Emitting Diode (LED) behind the cutout
in the opaque layer of the overlay causes the icon to
appear silhouetted against an amber field through
the translucent outer layer of the overlay when the
indicator is illuminated from behind by the LED,
which is soldered onto the instrument cluster elec-
tronic circuit board. The fuel filter clogged indicator
is serviced as a unit with the instrument cluster.
OPERATION
The fuel filter clogged indicator gives an indication
to the vehicle operator when the pressure in the fuel
system is low, which could indicate that the fuel filter
is clogged. This indicator is controlled by a transistor
on the instrument cluster circuit board based upon
cluster programming and electronic messages
received by the cluster from the Engine Control Mod-
VAINSTRUMENT CLUSTER 8J - 15

ule (ECM) over the Controller Area Network (CAN)
data bus. The fuel filter clogged indicator Light Emit-
ting Diode (LED) is completely controlled by the
instrument cluster logic circuit, and that logic will
only allow this indicator to operate when the instru-
ment cluster detects that the ignition switch is in the
On position. Therefore, the LED will always be off
when the ignition switch is in any position except
On. The LED only illuminates when it is provided a
path to ground by the instrument cluster transistor.
The instrument cluster will turn on the fuel filter
clogged indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the fuel filter clogged indi-
cator is illuminated by the cluster for about two sec-
onds as a bulb test.
²Fuel Filter Clogged Lamp-On Message-
Each time the cluster receives a lamp-on message
from the ECM, the fuel filter clogged indicator will
be illuminated. The indicator remains illuminated
until the cluster receives a lamp-off message from
the ECM, or until the ignition switch is turned to the
Off position, whichever occurs first.
The ECM continually monitors the low fuel pres-
sure sensor located at the inlet of the high pressure
fuel pump to decide whether the fuel system is in
good operating condition. The ECM then sends the
proper lamp-on or lamp-off messages to the instru-
ment cluster. If the ECM sends a lamp-on message
after the bulb test, it indicates that the ECM has
detected a low pressure condition in the fuel system,
which could result from a clogged fuel filter or from
any other restrictions in the fuel delivery system.
The ECM will store a Diagnostic Trouble Code (DTC)
for any malfunction it detects. For proper diagnosis
of the low fuel pressure sensor, the ECM, the CAN
data bus, the electronic message inputs to the instru-
ment cluster, or the instrument cluster circuitry that
controls the fuel filter clogged indicator, a DRBIIIt
scan tool is required. Refer to the appropriate diag-
nostic information.
FUEL GAUGE
DESCRIPTION
A fuel gauge is standard equipment on all instru-
ment clusters. The fuel gauge is located in the lower
right corner of the instrument cluster, to the right of
the speedometer. The fuel gauge consists of a mov-
able gauge needle or pointer controlled by the instru-
ment cluster circuitry and a fixed 45 degree scale on
the cluster overlay that reads left-to-right from ªFº
(or Full) to ªEº (or Empty). An International Control
and Display Symbol icon for ªFuelº is located on thecluster overlay, directly to the left of the low end of
the scale.
The fuel gauge graphics are white against a black
field, making them clearly visible within the instru-
ment cluster in daylight. When illuminated from
behind by the panel lamps dimmer controlled cluster
illumination lighting with the exterior lamps turned
On, the white graphics appear amber. The orange
gauge needle is internally illuminated. Gauge illumi-
nation is provided by Light Emitting Diode (LED)
units soldered onto the instrument cluster electronic
circuit board. The fuel gauge is serviced as a unit
with the instrument cluster.
OPERATION
The fuel gauge gives an indication to the vehicle
operator of the level of fuel in the fuel tank. This
gauge is controlled by the instrument cluster circuit
board based upon cluster programming and a hard
wired input received by the cluster from the fuel
level sensor in the fuel tank. The fuel gauge is an air
core magnetic unit that receives battery current on
the instrument cluster electronic circuit board when
the instrument cluster detects that the ignition
switch is in the On position. The cluster is pro-
grammed to move the gauge needle back to the low
end of the scale after the ignition switch is turned to
the Off position. The instrument cluster circuitry
controls the gauge needle position and provides the
following features:
²Fuel Level Sensor Input (At Ignition On)-
When the cluster detects the ignition switch has been
turned to the On position, the cluster moves the
gauge needle to the proper relative position on the
gauge scale as signaled by the fuel level sensor with-
out any electronic damping.
²Fuel Level Sensor Input (After Ignition On)
- After the ignition switch has been turned to the On
position, the cluster applies an algorithm to the input
from the fuel level sensor to electronically dampen
gauge needle movement against the negative effect
that fuel sloshing within the fuel tank can have on
accurate gauge readings.
²Fuel Level Sensor Input Open- If the fuel
level sensor input to the instrument cluster is an
open circuit, the cluster will move the fuel gauge nee-
dle to the ªEº (Empty) position on the gauge scale,
but the low fuel indicator will not be illuminated.
The fuel level sensor in the fuel tank provides a
hard wired input to the instrument cluster circuitry
through the fuel level sense circuit. The fuel level
sensor is a potentiometer that changes resistance
according to the fuel level. As the fuel level
decreases, the resistance through the fuel level sen-
sor increases. The fuel level sensor and the fuel level
sense circuit to the instrument cluster can be diag-
8J - 16 INSTRUMENT CLUSTERVA
FUEL FILTER CLOGGED INDICATOR (Continued)