2005 MERCEDES-BENZ SPRINTER engine

INSTRUMENT CLUSTER
TABLE OF CONTENTS
page page
INSTRUMENT CLUSTER
DESCRIPTION..........................2
OPERATION............................5
DIAGNOSIS AND TESTING - INSTRUMENT
CLUSTER............................7
REMOVAL.............................7
INSTALLATION..........................9
ABS INDICATOR
DESCRIPTION..........................9
OPERATION............................9
AIRBAG INDICATOR
DESCRIPTION.........................10
OPERATION...........................10
AMBIENT TEMPERATURE INDICATOR
DESCRIPTION.........................11
OPERATION...........................11
BRAKE/PARK BRAKE INDICATOR
DESCRIPTION.........................11
OPERATION...........................12
BRAKE WEAR INDICATOR
DESCRIPTION.........................12
OPERATION...........................12
CHARGING INDICATOR
DESCRIPTION.........................13
OPERATION...........................13
CLOCK
DESCRIPTION.........................13
OPERATION...........................14
COOLANT LOW INDICATOR
DESCRIPTION.........................14
OPERATION...........................14
ENGINE TEMPERATURE GAUGE
DESCRIPTION.........................15
OPERATION...........................15
FUEL FILTER CLOGGED INDICATOR
DESCRIPTION.........................15
OPERATION...........................15
FUEL GAUGE
DESCRIPTION.........................16
OPERATION...........................16
GEAR SELECTOR INDICATOR
DESCRIPTION.........................17
OPERATION...........................17
HIGH BEAM INDICATOR
DESCRIPTION.........................17
OPERATION...........................17LOW FUEL INDICATOR
DESCRIPTION.........................18
OPERATION...........................18
LOW OIL LEVEL INDICATOR
DESCRIPTION.........................18
OPERATION...........................18
MAINTENANCE INDICATOR
DESCRIPTION.........................19
OPERATION...........................19
MALFUNCTION INDICATOR LAMP (MIL)
DESCRIPTION.........................20
OPERATION...........................20
MULTI-FUNCTION INDICATOR
DESCRIPTION.........................20
OPERATION...........................21
ODOMETER
DESCRIPTION.........................21
OPERATION...........................22
SEATBELT INDICATOR
DESCRIPTION.........................22
OPERATION...........................22
SPEEDOMETER
DESCRIPTION.........................23
OPERATION...........................23
TACHOMETER
DESCRIPTION.........................23
OPERATION...........................24
TRACTION CONTROL INDICATOR
DESCRIPTION.........................24
OPERATION...........................24
TRACTION CONTROL MALFUNCTION
INDICATOR
DESCRIPTION.........................25
OPERATION...........................25
TURN SIGNAL INDICATOR
DESCRIPTION.........................25
OPERATION...........................25
WAIT-TO-START INDICATOR
DESCRIPTION.........................26
OPERATION...........................26
WASHER FLUID INDICATOR
DESCRIPTION.........................27
OPERATION...........................27
WATER-IN-FUEL INDICATOR
DESCRIPTION.........................27
OPERATION...........................28
VAINSTRUMENT CLUSTER 8J - 1

INSTRUMENT CLUSTER
DESCRIPTION
The instrument cluster for this model is an Elec-
troMechanical Instrument Cluster (EMIC) that is
located above the steering column opening in the
instrument panel, directly in front of the driver (Fig.
1). The remainder of the EMIC, including the mounts
and the electrical connections, are concealed within
the instrument panel behind the cluster bezel and
beneath the instrument panel top cover for the clus-
ter. The instrument cluster includes analog gauges,
meters, indicators, and acoustic signal transmitters.
The EMIC module also incorporates a multi-func-
tion indicator that consists of a digital Liquid Crystal
Display (LCD) unit for displaying odometer/trip
odometer information, an electronic digital clock,
engine oil level information, automatic transmission
gear selector position (PRNDL), and certain diagnos-
tic information. The multi-function indicator also has
four push button switches, which provide the vehicle
operator with an interface to adjust certain inputs to
the instrument cluster and to select from multiple
display options. If the vehicle is equipped with the
appropriate options, the multi-function indicator also
provides an outside ambient temperature indicator
display and an Active Service SYStem (ASSYST)
engine oil maintenance indicator to display engine oil
level and maintenance reminders.
The EMIC gauges and indicators are visible
through a dedicated opening in the cluster bezel on
the instrument panel and are protected by a clear
plastic cluster lens (Fig. 2) that is secured by eightintegral latches to the molded black plastic cluster
hood. Four, black plastic multi-function indicator
switch push buttons protrude through dedicated
holes in a rectangular black plastic switch bezel that
is integral to the cluster lens and located near the
lower edge of the cluster directly below the multi-
function indicator LCD unit. The cluster hood serves
as a visor and shields the face of the cluster from
ambient light and reflections to reduce glare. The
cluster hood has eight integral latches that engage
eight integral latch tabs on the cluster rear cover,
sandwiching the cluster housing unit between the
hood and the rear cover. The cluster hood also has
two integral pivot loops molded into its underside
that engage two pairs of molded pivot hooks that are
integral to the top of the instrument panel base
structure. These pivots allow the cluster to be rolled
rearward to ease service access to the wire harness
connectors at the back of the cluster.
The rear of the cluster housing and the EMIC elec-
tronic circuitry are protected by the molded plastic
rear cover. A mounting ear at each upper corner of
the rear cover are used to secure the EMIC to the
molded plastic instrument panel base unit with two
screws. The rear cover includes clearance holes for
the two cluster connector receptacles on the cluster
electronic circuit board. The connector receptacles on
the back of the cluster electronic circuit board con-
nect the EMIC to the vehicle electrical system
through two take outs with connectors from the vehi-
cle wire harness. The EMIC rear cover includes a
molded mounting tab and a latch feature that
secures the RKE/immobilizer module to the back of
the cluster. The RKE/immobilizer module is con-
nected to the vehicle electrical system through a sep-
Fig. 1 Instrument Cluster
1 - COVER
2 - BEZEL
3 - INSTRUMENT CLUSTER
4 - STEERING WHEEL
5 - MULTI-FUNCTION SWITCH
6 - SPEED CONTROL SWITCH
Fig. 2 Instrument Cluster Components
1 - LENS
2 - HOOD
3 - CLUSTER HOUSING
4 - REAR COVER
8J - 2 INSTRUMENT CLUSTERVA

arate take out and connector of the vehicle wire
harness.
Located between the rear cover and the cluster
hood is the cluster housing. The molded plastic clus-
ter housing serves as the carrier for the cluster elec-
tronic circuit board and circuitry, the cluster
connector receptacles, the gauges, a Light Emitting
Diode (LED) for each cluster indicator and general
illumination lamp, the multi-function indicator LCD
unit, electronic tone generators, the cluster overlay,
the gauge pointers, the multi-function indicator
switches and the four switch push buttons.
The cluster overlay is a laminated plastic unit. The
dark, visible, outer surface of the overlay is marked
with all of the gauge dial faces and graduations, but
this layer is also translucent. The darkness of this
outer layer prevents the cluster from appearing clut-
tered or busy by concealing the cluster indicators
that are not illuminated, while the translucence of
this layer allows those indicators and icons that are
illuminated to be readily visible. The underlying
layer of the overlay is opaque and allows light from
the LED for each of the various indicators and illu-
mination lamps behind it to be visible through the
outer layer of the overlay only through predeter-
mined cutouts. A rectangular opening in the overlay
at the base of the speedometer provides a window
through which the illuminated multi-function indica-
tor LCD unit can be viewed.
Several versions of the EMIC module are offered
on this model. These versions accommodate all of the
variations of optional equipment and regulatory
requirements for the various markets in which the
vehicle will be offered. The microprocessor-based
EMIC utilizes integrated circuitry, Electrically Eras-
able Programmable Read Only Memory (EEPROM)
type memory storage, information carried on the
Controller Area Network (CAN) data bus, along with
several hard wired analog and multiplexed inputs to
monitor systems, sensors and switches throughout
the vehicle.
In response to those inputs, the hardware and soft-
ware of the EMIC allow it to control and integrate
many electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the CAN data bus. (Refer
to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/COMMUNICATION - DESCRIPTION -
CAN BUS).
Besides typical instrument cluster gauge and indi-
cator support, the electronic functions and features
that the EMIC supports or controls include the fol-
lowing:
²Active Service System- In vehicles equipped
with the Active Service SYSTem (ASSYST) engine oilmaintenance indicator option, the EMIC electronic
circuit board includes a second dedicated micropro-
cessor. This second microprocessor evaluates various
data including time, mileage, and driving conditions
to calculate the required engine oil service intervals,
and provides both visual and audible alerts to the
vehicle operator when certain engine oil maintenance
services are required.
²Audible Warnings- The EMIC electronic cir-
cuit board is equipped with an audible tone generator
and programming that allows it to provide various
audible alerts to the vehicle operator, including buzz-
ing and chime tones. An audible contactless elec-
tronic relay is also soldered onto the circuit board to
produce audible clicks that is synchronized with turn
signal indicator flashing to emulate the sounds of a
conventional turn signal or hazard warning flasher.
These audible clicks can occur at one of two rates to
emulate both normal and bulb-out turn or hazard
flasher operation. (Refer to 8 - ELECTRICAL/
CHIME/BUZZER - DESCRIPTION).
²Panel Lamps Dimming Control- The EMIC
provides a hard wired 12-volt Pulse-Width Modulated
(PWM) output that synchronizes the dimming level
of all panel lamps dimmer controlled lamps with that
of the cluster general illumination lamps and multi-
function indicator.
The EMIC houses four analog gauges and has pro-
visions for up to nineteen indicators (Fig. 3). The
EMIC includes the following analog gauges:
²Coolant Temperature Gauge
²Fuel Gauge
²Speedometer
²Tachometer
The EMIC includes provisions for the following
indicators (Fig. 3):
²Airbag (SRS) Indicator
²Antilock Brake System (ABS) Indicator
²Brake Indicator
²Brake Wear Indicator
²Charging Indicator
²Clogged Fuel Filter Indicator
²Coolant Low Indicator
²High Beam Indicator
²Low Fuel Indicator
²Malfunction Indicator Lamp (MIL)
²Multi-Function Indicator (LCD)
²Seatbelt Indicator
²Traction Control (ASR) Indicator
²Traction Control (ASR) Malfunction Indica-
tor
²Turn Signal (Right and Left) Indicators
²Washer Fluid Indicator
²Wait-To-Start Indicator
²Water-In-Fuel Indicator
VAINSTRUMENT CLUSTER 8J - 3
INSTRUMENT CLUSTER (Continued)

Except for the indications provided within the
multi-function indicator LCD unit, each indicator in
the EMIC is illuminated by a dedicated LED that is
soldered onto the EMIC electronic circuit board.
Cluster illumination is accomplished by dimmable
LED back lighting, which illuminates the gauges for
visibility when the exterior lighting is turned on. The
cluster general illumination LED units are also sol-
dered onto the EMIC electronic circuit board. The
LED units are not available for service replacement
and, if damaged or faulty, the entire EMIC must be
replaced.
Hard wired circuitry connects the EMIC to the
electrical system of the vehicle. These hard wired cir-cuits are integral to the vehicle wire harnesses,
which are routed throughout the vehicle and retained
by many different methods. These circuits may be
connected to each other, to the vehicle electrical sys-
tem and to the EMIC through the use of a combina-
tion of soldered splices, splice block connectors, and
many different types of wire harness terminal con-
nectors and insulators. Refer to the appropriate wir-
ing information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, further details on wire harness routing
and retention, as well as pin-out and location views
for the various wire harness connectors, splices and
grounds.
Fig. 3 Gauges & Indicators
1 - AIRBAG INDICATOR 14 - SEATBELT INDICATOR
2 - TACHOMETER 15 - ABS INDICATOR
3 - LEFT TURN INDICATOR 16 - MULTI-FUNCTION INDICATOR PLUS/MINUS SWITCH PUSH
BUTTONS
4 - SPEEDOMETER 17 - MULTI-FUNCTION INDICATOR (INCLUDES: CLOCK, GEAR
SELECTOR INDICATOR, ODOMETER, TRIP ODOMETER,
ENGINE OIL LEVEL DATA, AMBIENT TEMPERATURE
INDICATOR [OPTIONAL], & ACTIVE SERVICE SYSTEM
[ASSYST] ENGINE OIL MAINTENANCE INDICATOR [OPTIONAL])
5 - TRACTION CONTROL INDICATOR 18 - MULTI-FUNCTION INDICATOR MODE (MILES
[KILOMETERS]/TIME) SWITCH PUSH BUTTONS
6 - RIGHT TURN INDICATOR 19 - COOLANT LOW INDICATOR
7 - ENGINE TEMPERATURE GAUGE 20 - BRAKE INDICATOR
8 - FUEL GAUGE 21 - OIL LEVEL INDICATOR
9 - WAIT-TO-START INDICATOR 22 - BRAKE WEAR INDICATOR
10 - WASHER FLUID INDICATOR (OPTIONAL) 23 - WATER-IN-FUEL INDICATOR
11 - LOW FUEL INDICATOR 24 - CHARGING INDICATOR
12 - TRACTION CONTROL MALFUNCTION INDICATOR 25 - HIGH BEAM INDICATOR
13 - MALFUNCTION INDICATOR LAMP 26 - FUEL FILTER CLOGGED INDICATOR
8J - 4 INSTRUMENT CLUSTERVA
INSTRUMENT CLUSTER (Continued)

INDICATORS
Indicators are located in various positions within
the EMIC and are all connected to the EMIC elec-
tronic circuit board. The ambient temperature indica-
tor (optional), brake indicator, brake wear indicator,
charging indicator, coolant low indicator, high beam
indicator, low fuel indicator, seatbelt indicator, turn
signal indicators, and washer fluid indicator operate
based upon hard wired inputs to the EMIC. The air-
bag (SRS) indicator is normally controlled by a hard
wired input from the Airbag Control Module (ACM);
however, if the EMIC sees an abnormal or no input
from the ACM, it will automatically turn the airbag
indicator On until the hard wired input from the
ACM has been restored. The Malfunction Indicator
Lamp (MIL) is normally controlled by CAN data bus
messages from the Engine Control Module (ECM);
however, if the EMIC loses CAN data bus communi-
cation, the EMIC circuitry will automatically turn
the MIL on until CAN data bus communication is
restored. The EMIC uses CAN data bus messages
from the ECM, the ACM, and the Controller Antilock
Brake to control all of the remaining indicators.
The various EMIC indicators are controlled by dif-
ferent strategies; some receive battery feed from the
EMIC circuitry and have a switched ground, while
others are grounded through the EMIC circuitry and
have a switched battery feed. However, all indicators
are completely controlled by the EMIC microproces-
sor based upon various hard wired and electronic
message inputs. Except for the indications provided
by the multi-function indicator Liquid Crystal Dis-
play (LCD) unit, all indicators are illuminated at a
fixed intensity, which is not affected by the selected
illumination intensity of the EMIC general illumina-
tion lamps.
The hard wired indicator inputs may be diagnosed
using conventional diagnostic methods. However,
proper testing of the EMIC circuitry and the CAN
bus message controlled indicators requires the use of
a DRBIIItscan tool. Refer to the appropriate diag-
nostic information. Specific details of the operation
for each indicator may be found elsewhere in this
service information.
CLUSTER ILLUMINATION
The EMIC has several general illumination lamps
that are illuminated when the exterior lighting is
turned on with the multi-function switch. The illumi-
nation intensity of these lamps is adjusted by a dim-
ming level input received from the multi-function
indicator ª+º (plus) and ª±º (minus) switch push but-
tons that extend through the lower edge of the clus-
ter lens below the right end of the multi-function
indicator. When the exterior lighting is turned Off,
the display is illuminated at maximum brightness.When the exterior lighting is turned On and the
transmission gear selector is in the Park position,
depressing the plus switch push button brightens the
display lighting, and depressing the minus switch
push button dims the display lighting. The EMIC
also provides a Pulse-Width Modulated (PWM) panel
lamps dimmer output that can be used to synchro-
nize the illumination lighting levels of external illu-
mination lamps (up to about 23 to 30 watts) with
that of the EMIC.
The hard wired multi-function switch input and
the EMIC panel lamps dimmer output may be diag-
nosed using conventional diagnostic methods. How-
ever, proper testing of the PWM control of the EMIC
and the electronic dimming level inputs from the
multi-function indicator push buttons requires the
use of a DRBIIItscan tool. Refer to the appropriate
diagnostic information.
INPUT AND OUTPUT CIRCUITS
HARD WIRED INPUTS
The hard wired inputs to the EMIC include the fol-
lowing:
NOTE: Final approved circuit names were not yet
available at the time this information was compiled.
²Airbag Indicator Driver
²Ambient Temperature Sensor Signal
(Optional)
²Brake Wear Indicator Sense
²Charging Indicator Driver
²Coolant Level Switch Sense
²Front Door Jamb Switch Sense
²Fuel Level Sensor Signal
²Fused B(+)
²Fused Ignition Switch Output
²High Beam Indicator Driver
²Key-In Ignition Switch Sense
²Left Turn Signal
²Park Brake Switch Sense
²Right Turn Signal
²Seat Belt Switch Sense
²Washer Fluid Switch Sense (Optional)
Refer to the appropriate wiring information for
additional details.
HARD WIRED OUTPUTS
The hard wired outputs of the EMIC include the
following:
NOTE: Final approved circuit names were not yet
available at the time this information was compiled.
²Engine Running Relay Control
²Panel Lamps Driver
8J - 6 INSTRUMENT CLUSTERVA
INSTRUMENT CLUSTER (Continued)

illuminated by the instrument cluster for about two
seconds as a bulb test.
²Brake Wear Sensor Input- Each time the
cluster detects ground on the brake wear sense cir-
cuit (brake wear sensor closed = brake lining wear
limit exceeded) while the ignition switch is in the On
position, the brake wear indicator is illuminated. The
indicator remains illuminated until the brake wear
sense input to the cluster is an open circuit (brake
wear sensor open = brake lining wear within limits),
or until the ignition switch is turned to the Off posi-
tion, whichever occurs first.
A brake wear sensor located at each wheel provides
a hard wired ground input to the instrument cluster
circuitry through the brake wear sense circuit when-
ever the brake linings for that wheel have exceeded
their wear limits. The four normally open brake wear
sensors are connected in parallel between ground and
instrument cluster. The brake wear sensors and their
input circuit to the instrument cluster can be diag-
nosed using conventional diagnostic tools and meth-
ods. For proper diagnosis of the instrument cluster
circuitry that controls the brake wear indicator, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
CHARGING INDICATOR
DESCRIPTION
A charging indicator is standard equipment on all
instrument clusters. The charging indicator is located
near the lower edge of the instrument cluster, to the
left of the multi-function indicator display. The
charging indicator consists of the International Con-
trol and Display Symbol icon for ªBattery Charging
Conditionº imprinted within a rectangular cutout in
the opaque layer of the instrument cluster overlay.
The dark outer layer of the overlay prevents the indi-
cator from being clearly visible when it is not illumi-
nated. A red Light Emitting Diode (LED) behind the
cutout in the opaque layer of the overlay causes the
icon to appear silhouetted against a red 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 charging indicator is ser-
viced as a unit with the instrument cluster.
OPERATION
The charging indicator gives an indication to the
vehicle operator when the electrical system voltage is
too low. This indicator is controlled by a transistor on
the instrument cluster circuit board based upon clus-
ter programming and a hard wired input from the
generator. The charging indicator Light EmittingDiode (LED) is completely controlled by the instru-
ment cluster logic circuit, and that logic will only
allow this indicator to operate when the instrument
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 charging indica-
tor for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position with the engine not run-
ning the charging indicator is illuminated by the
instrument cluster as a bulb test.
²Generator Input- Each time the cluster
detects that the voltage of the generator input is 12.7
volts or lower while the engine is running, the charg-
ing indicator will be illuminated. The indicator
remains illuminated until the cluster detects that the
voltage of the generator input is above 12.7 volts, or
until the ignition switch is turned to the Off position,
whichever occurs first.
The generator provides a hard wired input to the
instrument cluster circuitry on the engine running
(D+) circuit. If the instrument cluster turns on the
indicator while the engine is running, it may indicate
that the charging system requires service. The gener-
ator input circuit to the instrument cluster can be
diagnosed using conventional diagnostic tools and
methods. For proper diagnosis of the charging sys-
tem, or the instrument cluster circuitry that controls
the charging indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
CLOCK
DESCRIPTION
An electronic digital clock is standard equipment
on all instrument clusters. In vehicles equipped with
the optional ambient temperature indicator, the clock
indication can be toggled with the ambient tempera-
ture indication on the right side of the multi-function
indicator Liquid Crystal Display (LCD) located near
the lower edge of the instrument cluster, directly
below the speedometer. The clock provides a 12 hour-
based, digital indication of the current hours and
minutes. The indications of the clock are not visible
when the LCD is not illuminated. When illuminated
the indications appear as dark characters silhouetted
against an amber field. When the exterior lighting is
turned Off, the display is illuminated at maximum
brightness. When the exterior lighting is turned On
the display illumination level can be adjusted in con-
cert with the cluster general illumination lighting
VAINSTRUMENT CLUSTER 8J - 13
BRAKE WEAR INDICATOR (Continued)

using the ª+º (plus) and ª2º (minus) multi-function
indicator push buttons. The clock is serviced as a
unit with the instrument cluster.
OPERATION
The clock gives an indication to the vehicle opera-
tor of the current time. The electronic digital clock is
controlled by the instrument cluster microprocessor
based upon cluster programming. The clock display is
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indication
to be viewed when the multi-function indicator Liq-
uid Crystal Display (LCD) is activated. However, the
clock remains functional regardless of the ignition
switch position.
The vehicle operator can choose to have the
optional ambient temperature indicator displayed
instead of the clock information, but the clock and
ambient temperature indicator cannot be displayed
at the same time. The clock or ambient temperature
indicator display option is selected using the multi-
function indicator clock switch on the instrument
cluster circuit board. This switch is actuated manu-
ally by depressing the clock switch push button that
extends through the lower edge of the cluster lens
below the left end of the multi-function indicator.
Actuating this switch momentarily will toggle the
display between the clock and ambient temperature
indicator modes. Actuating this switch twice within
about one second will cause the display to toggle, but
then automatically revert to the originally selected
mode after about twenty seconds.
See the owner's manual in the vehicle glove box for
more information on the features, use, operation and
setting procedures for the clock. For proper testing of
the instrument cluster circuitry that controls the
clock functions, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
COOLANT LOW INDICATOR
DESCRIPTION
A coolant low indicator is standard equipment on
all instrument clusters. The coolant low indicator is
located near the lower edge of the instrument cluster,
to the left of the multi-function indicator display. The
coolant low indicator consists of the International
Control and Display Symbol icon for ªLow Engine
Coolantº imprinted within a rectangular cutout in
the opaque layer of the instrument cluster overlay.
The dark outer layer of the overlay prevents the indi-
cator from being clearly visible when it is not illumi-
nated. A red Light Emitting Diode (LED) behind the
cutout in the opaque layer of the overlay causes the
icon to appear silhouetted against a red field throughthe 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 coolant low indicator is ser-
viced as a unit with the instrument cluster.
OPERATION
The coolant low indicator gives an indication to the
vehicle operator when the engine coolant level is low.
This indicator is controlled by a transistor on the
instrument cluster circuit board based upon cluster
programming and a hard wired input received by the
cluster from the engine coolant level switch. The cool-
ant low indicator Light Emitting Diode (LED) is com-
pletely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator to
operate when the instrument 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 instru-
ment cluster transistor. The instrument cluster will
turn on the coolant low indicator for the following
reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the coolant low indicator is
illuminated for about two seconds as a bulb test.
²Engine Coolant Level Switch Input- Each
time the cluster detects an appropriate input on the
low coolant fluid level sense circuit (engine coolant
level switch resistance low = engine coolant level low)
while the ignition switch is in the On position, the
coolant low indicator will be illuminated. The indica-
tor remains illuminated until the low coolant fluid
level sense input to the cluster changes (engine cool-
ant level switch resistance high = engine coolant
level full), or until the ignition switch is turned to
the Off position, whichever occurs first. The engine
coolant level switch also features a diagnostic resis-
tor connected in parallel between the switch input
and output to provide the cluster with verification
that the low coolant fluid level sense circuit is not
open or shorted.
The engine coolant level switch integral to the cool-
ant bottle provides a hard wired input to the instru-
ment cluster circuitry through the low coolant fluid
level sense circuit. The engine coolant level switch
and the low coolant fluid level sense circuit to the
instrument cluster can be diagnosed using conven-
tional diagnostic tools and methods. For proper diag-
nosis of the instrument cluster circuitry that controls
the coolant low indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
8J - 14 INSTRUMENT CLUSTERVA
CLOCK (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