2006 MERCEDES-BENZ SPRINTER warning light

the status of the driver side front seat belt. This
audible warning occurs independent of the visual
warning provided by the EMIC ªSeatbeltº indicator.
²Lights-On Warning- The EMIC chime tone
generator will generate repetitive chime tones at a
fast rate when either front door is opened with the
ignition switch in any position except On, and the
exterior lights are turned On. The EMIC uses inter-
nal programming and hard wired inputs from the left
(lighting) control stalk of the multi-function switch,
the ignition switch, and both front door jamb
switches to determine the current status of these
switches. This chime will continue to sound until the
exterior lighting is turned Off, until the ignition
switch is turned to the On position, or until both
front doors are closed, whichever occurs first.
²Key-In-Ignition Warning- The EMIC chime
tone generator will generate repetitive chime tones at
a fast rate when the key is in the ignition lock cylin-
der, the ignition switch is in any position except On,
and either front door is opened. The EMIC uses
internal programming and hard wired inputs from
the key-in ignition switch, the ignition switch, and
both front door jamb switches to determine the cur-
rent status of these switches. The chime will con-
tinue to sound until the key is removed from the
ignition lock cylinder, until the ignition switch is
turned to the On position, or until both front doors
are closed, whichever occurs first.
²Audible Turn Signal/Hazard Warning Sup-
port- The EMIC contactless relay will generate
repetitive clicks at a slow rate during normal turn
signal/hazard warning operation, or at a fast rate
when a turn signal lamp bulb or circuit is inopera-
tive, in concert with the operation of the turn signal
indicators in the cluster. These clicks are designed to
emulate the sound of the opening and closing of the
contact points in a conventional electromechanical
turn signal or hazard warning flasher. The EMIC
uses a hard wired input received from the turn sig-
nal relay in the fuse block beneath the steering col-
umn through the turn signal or hazard warning
switch circuitry of the multi-function switch to deter-
mine when to flash the turn signal indicators and
activate the contactless relay on the cluster electronic
circuit board. The turn signal clicks will continue to
sound until the turn signal switch is turned Off, or
until the ignition switch is turned to the Off position,
whichever occurs first. The hazard warning clicks
will continue to sound until the hazard warning
switch is turned Off.
The EMIC provides chime service for all available
features in the chime warning system. The EMIC relies
upon its internal programming and hard wired inputs
from the front door ajar switches, the key-in ignition
switch, the ignition switch, the seat belt switch, and the
turn signal/hazard warning (multi-function) switches.
The EMIC relies upon electronic message inputsreceived from other electronic modules over the CAN
data bus network to provide chime service for the low
engine oil level warning. Upon receiving the proper
inputs, the EMIC activates the chime tone generator or
the contactless relay to provide the audible warning to
the vehicle operator. The internal programming of the
EMIC determines the priority of each chime request
input that is received, as well as the rate and duration
of each tone that is to be generated. See the owner's
manual in the vehicle glove box for more information on
the features provided by the chime warning system.
The hard wired chime warning system inputs to
the EMIC, as well as other hard wired circuits for
this system may be diagnosed and tested using con-
ventional diagnostic tools and procedures. However,
conventional diagnostic methods may not prove con-
clusive in the diagnosis of the EMIC, the CAN data
bus network, or the electronic message inputs used
by the EMIC to provide chime warning system ser-
vice. The most reliable, efficient, and accurate means
to diagnose the EMIC, the CAN data bus network,
and the electronic message inputs for the chime
warning system requires the use of a diagnostic scan
tool. Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - CHIME WARNING
SYSTEM
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-
tem. Failure to take the proper precautions could
result in accidental airbag deployment.
The hard wired chime warning system inputs to
the ElectroMechanical Instrument Cluster (EMIC),
as well as other hard wired circuits for this system
may be diagnosed and tested using conventional
diagnostic tools and procedures. However, conven-
tional diagnostic methods may not prove conclusive
in the diagnosis of the EMIC, the Controller Area
Network (CAN) data bus network, or the electronic
message inputs used by the EMIC to provide chime
warning system service. The most reliable, efficient,
and accurate means to diagnose the EMIC, the CAN
data bus network, and the electronic message inputs
for the chime warning system requires the use of a
diagnostic scan tool. Refer to the appropriate diag-
nostic information.
8B - 2 CHIME/BUZZERVA

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 oil
maintenance indicator option, the EMIC electronic
circuit board includes a second dedicated micropro-
cessor. This second microprocessor evaluates various
data including time, mileage, and driving conditionsto 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
²Constant Engine Speed (ADR) Indicator
²Coolant Low Indicator
²Electronic Stability Program (ESP) Indica-
tor
²High Beam Indicator
²Low Fuel Indicator
²Malfunction Indicator Lamp (MIL)
²Multi-Function Indicator (LCD)
²Park Brake Indicator
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

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.
The EMIC modules for this model are serviced only
as complete units. The EMIC module cannot be
adjusted or repaired. If a gauge, an LED indicator,
the multi-fuction indicator LCD unit, an electronic
tone generator, the electronic circuit board, the cir-
cuit board hardware, the cluster overlay, the cluster
housing, the cluster hood, the cluster lens, or the
cluster rear cover are damaged or faulty, the entire
EMIC module must be replaced.
OPERATION
The ElectroMechanical Instrument Cluster (EMIC)
is designed to allow the vehicle operator to monitor
the conditions of many of the vehicle components and
operating systems. The gauges, meters and indicators
in the EMIC provide valuable information about the
powertrain, fuel and emissions systems, cooling sys-
tem, lighting systems, safety systems and many
other convenience items. The EMIC is installed in
the instrument panel so that all of these monitors
can be easily viewed by the vehicle operator when
driving, while still allowing relative ease of access for
service. The microprocessor-based EMIC hardware
and software uses various inputs to control the
gauges and indicators visible on the face of the clus-
ter. Some of these inputs are hard wired, but many
are in the form of electronic messages that are trans-
mitted by other electronic modules over the Control-
ler Area Network (CAN) data bus network. (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/COMMUNICATION - OPERATION).
The EMIC microprocessor smooths the input data
using algorithms to provide gauge readings that are
accurate, stable and responsive to operating condi-
tions. These algorithms are designed to provide
gauge readings during normal operation that are con-
sistent with customer expectations. However, when
abnormal conditions exist such as high coolant tem-
perature, the algorithm can drive the gauge pointer
to an extreme position and the microprocessor can
sound a chime through the on-board audible tone
generator to provide distinct visual and audible indi-
cations of a problem to the vehicle operator. The
instrument cluster circuitry also provides audible
turn signal and hazard warning support by emulat-
ing the ªtickingº sound associated with a conven-
tional electro-mechanical flasher using a contactless
relay. The relay will also provide an indication of a
turn signal failure by sounding at double the usual
frequency. Each audible warning is provided to the
vehicle operator to supplement a visual indication.
The EMIC circuitry operates on battery current
received through a non-switched fused B(+) circuit,
and on a fused ignition switch output circuit. TheEMIC circuitry is grounded through a ground circuit
and take out of the frame wire harness with an eye-
let terminal connector that is secured to a stud by a
nut at a ground location on the dash panel just for-
ward of the instrument cluster. Separate switched
ground inputs from the key-in ignition switch and
the front door jamb switches provide wake-up signals
to the EMIC circuitry. This arrangement allows the
EMIC to provide some features regardless of the igni-
tion switch position, while other features will operate
only with the ignition switch in the On position.
Proper diagnosis and testing of the EMIC, the
CAN data bus, the data bus electronic message
inputs to and outputs from the EMIC, as well as the
retrieval or erasure of a Diagnostic Trouble Code
(DTC) requires the use of a diagnostic scan tool.
Refer to the appropriate diagnostic information. See
the owner's manual in the vehicle glove box for more
information on the features, use and operation of the
EMIC.
GAUGES
All gauges receive battery current through the
EMIC circuitry only when the instrument cluster
detects the ignition switch is in the On position. With
the ignition switch in the Off position, battery cur-
rent is not supplied to any gauges and the EMIC cir-
cuitry is programmed to move all of the gauge
needles back to the low end of their respective scales.
Therefore, the gauges do not accurately indicate any
vehicle condition unless the ignition switch is in the
On position.
All of the EMIC gauges are air core magnetic
units. Two fixed electromagnetic coils are located
within each gauge. These coils are wrapped at right
angles to each other around a movable permanent
magnet. The movable magnet is suspended within
the coils on one end of a pivot shaft, while the gauge
needle is attached to the other end of the shaft. One
of the coils has a fixed current flowing through it to
maintain a constant magnetic field strength. Current
flow through the second coil changes, which causes
changes in its magnetic field strength. The current
flowing through the second coil is changed by the
EMIC circuitry in response to messages received over
the CAN data bus. The gauge needle moves as the
movable permanent magnet aligns itself to the
changing magnetic fields created around it by the
electromagnets.
Proper diagnosis and testing of the gauges, the
CAN data bus and the electronic data bus message
inputs to the EMIC that control each gauge require
the use of a diagnostic scan tool. Refer to the appro-
priate diagnostic information. Specific operation
details for each gauge may be found elsewhere in
this service information.
VAINSTRUMENT CLUSTER 8J - 5

GROUNDS
The EMIC receives and supplies a ground path to
several switches and sensors through the following
hard wired circuits:
²Ambient Temperature Sensor Return
(Optional)
²Fuel Level Sensor Return
²Ground
Refer to the appropriate wiring information for
additional details.
COMMUNICATION
The EMIC has provisions for the following commu-
nication circuits:
²CAN Data Bus - High
²CAN Data Bus - Low
²Diagnostic Serial Communication Interface
(SCI) Data Bus Line
Refer to the appropriate wiring information for
additional details.
DIAGNOSIS AND TESTING - INSTRUMENT
CLUSTER
The hard wired inputs to and outputs from the
instrument cluster may be diagnosed and tested
using conventional diagnostic tools and procedures.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
If the instrument cluster is completely inoperative,
be certain to check the fused B(+) circuit fuses and
wiring for the instrument cluster. If the cluster gen-
eral illumination is inoperative, be certain to check
the instrument lighting fuse and the input circuit to
the instrument cluster from the exterior lighting cir-
cuitry of the multi-function switch on the steering
column.
Conventional diagnostic methods may not prove
conclusive in the diagnosis of the instrument cluster.
In order to obtain conclusive testing of the instru-
ment cluster, the Controller Area Network (CAN)
data bus network and all of the electronic modules
that provide inputs to or receive outputs from the
instrument cluster must also be checked. The most
reliable, efficient, and accurate means to diagnose
the instrument cluster, the CAN data bus network,
and the electronic modules that provide inputs to or
receive outputs from the instrument cluster requires
the use of a diagnostic scan tool and the appropriate
diagnostic information. The diagnostic scan tool can
provide confirmation that the CAN data bus network
is functional, that all of the modules are sending and
receiving the proper electronic messages over the
CAN data bus, and that the instrument cluster isreceiving the proper hard wired inputs and respond-
ing with the proper hard wired outputs needed to
perform its many functions.
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-
tem. Failure to take the proper precautions could
result in accidental airbag deployment.
STANDARD PROCEDURE
CLUSTER PROGRAMMING
NOTE: After replacing the Instrument Cluster (IC)
according to the service procedures, determine the
optional equipment on the vehicle by accessing the
sales code information using the Vehicle Identifica-
tion Number (VIN) on DealerCONNECT.
(1) Using the DRBIIIt, selectMISCELLANEOUS
FUNCTIONSin the Instrument Cluster (IC) section.
(2) SelectMODULE SERVICE REPLACE-
MENT.
(3) Following the prompts on the DRBIIIt, enter
the correct parameters that are applicable to the
vehicle. Use the sales code information and visual
inspection to obtain the correct parameters.
CAUTION: Do not lock down the instrument cluster
until the following steps are followed or the instru-
ment cluster may be irreversibly damaged.
(4) After entering the proper parameters into the
IC, turn the ignition switch to the OFF position for
30 seconds, then turn the ignition switch ON.
(5) Test drive the vehicle for at least 10 minutes
before proceeding.
(6) Check ALL modules for any parameterization
DTCs. If any parameterization DTCs are present, one
or more parameters entered into the IC are incorrect.
Verify all parameters entered using the sales code
information and visual inspection of the vehicle.
(7) If the parameters entered are verified as cor-
rect and parameterization DTCs are still present,
refer to the appropriate diagnostic information.
(8) If no parameterization DTCs are present, lock
down the IC.
VAINSTRUMENT CLUSTER 8J - 7

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 ECM
indicating 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 messageinputs to the instrument cluster, or the instrument
cluster circuitry that controls the engine coolant tem-
perature gauge, a diagnostic scan tool is required.
Refer to the appropriate diagnostic information.
ESP INDICATOR
DESCRIPTION
An Electronic Stability Program (ESP) indicator is
standard equipment on all instrument clusters, but is
only functional on vehicles equipped with the
optional ESP system. The ESP indicator is located
near the lower edge of the instrument cluster, to the
right of the multi-function indicator display. The ESP
indicator consists of a stencil-like cutout of the text
ªESPº 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 text to appear in amber through the
translucent outer layer of the overlay when the indi-
cator is illuminated from behind by the LED, which
is soldered onto the instrument cluster electronic cir-
cuit board. The ESP indicator is serviced as a unit
with the instrument cluster.
OPERATION
The ESP indicator gives an indication to the vehi-
cle operator when the ESP system is faulty or inop-
erative. This indicator is controlled by a transistor on
the instrument cluster circuit board based upon clus-
ter programming and electronic messages received by
the cluster from the Controller Antilock Brake (CAB)
over the Controller Area Network (CAN) data bus.
The ESP indicator Light Emitting Diode (LED) is
completely 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 ESP indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the ESP indicator is illu-
minated by the cluster for about two seconds as a
bulb test.
²ESP Lamp-On Message- Each time the clus-
ter receives a lamp-on message from the CAB, the
ESP indicator will be illuminated. The indicator
remains illuminated until the cluster receives a
lamp-off message from the CAB, or until the ignition
switch is turned to the Off position, whichever occurs
first.
8J - 16 INSTRUMENT CLUSTERVA

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. The instrument cluster
applies a fuel tank characteristic curve and fuel tank
reserve valve setting to the fuel level sensor input,
which must be configured when the cluster is initial-
ized. These characteristics determine the algorithm
the cluster uses to display the fuel level data on the
fuel gauge and the control for the low fuel warning
indicator. As the fuel level decreases, the resistance
through the fuel level sensor increases. The fuel level
sensor and the fuel level sense circuit to the instru-
ment cluster can be diagnosed using conventional
diagnostic tools and methods. For proper diagnosis of
the instrument cluster circuitry that controls the fuel
gauge, a diagnostic scan tool is required. Refer to the
appropriate diagnostic information.
GEAR SELECTOR INDICATOR
DESCRIPTION
An electronic automatic transmission gear selector
indicator is standard equipment on all instrument
clusters. The gear selector indicator information is
displayed in the center of the multi-function indicator
Liquid Crystal Display (LCD) located near the lower
edge of the instrument cluster, directly below the
speedometer. The gear selector indicator displays the
following characters as they are selected: ªP,º ªR,º
ªN,º ªD,º ª4,º ª3,º ª2,º and ª1.º Respectively, these
characters represent the currently selected park,
reverse, neutral, drive, fourth gear, third gear, second
gear, and first gear positions of the transmission gear
selector lever on the instrument panel.
The indications of the gear selector indicator are
not visible unless the multi-function indicator LCD is
illuminated and the engine is running. When illumi-
nated, each indication appears as a dark character
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 concert with the cluster general illumina-
tion lighting using the ª+º (plus) and ª2º (minus)
multi-function indicator push buttons. The gear
selector indicator is serviced as a unit with the
instrument cluster.
OPERATION
The electronic gear selector indicator gives an indi-
cation to the vehicle operator of the transmission
gear that is currently selected with the automatic
transmission gear selector lever. This indicator is
controlled by the instrument cluster circuit board
based upon cluster programming and electronic mes-
sages received from the Transmission Control Module
(TCM) over the Controller Area Network (CAN) data
bus. The gear selector indicator information is dis-
played by the multi-function indicator Liquid Crystal
Display (LCD) unit on the instrument cluster elec-
tronic circuit board. The multi-function indicator
LCD is completely controlled by the instrument clus-
ter logic circuit, and that logic will only allow the
gear selector indicator information to be displayed
when the instrument cluster detects that the ignition
switch is in the On position. Therefore, the gear
selector indicator will always be off when the ignition
switch is in any position except On.
The TCM continually monitors the transmission
range sensor, then sends the proper gear selector
indicator position messages to the instrument cluster.
For proper diagnosis of the transmission range sen-
sor, the TCM, the CAN data bus, or the electronic
message inputs to the instrument cluster that control
the gear selector indicator, a diagnostic scan tool is
8J - 18 INSTRUMENT CLUSTERVA

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 instrument cluster applies a fuel
tank characteristic curve and fuel tank reserve valve
setting to the fuel level sensor input, which must be
configured when the cluster is initialized. These
characteristics determine the algorithm the cluster
uses to display the fuel level data on the fuel gauge
and the control for the low fuel warning indicator.
The fuel level sensor and the fuel level sense circuit
to the instrument cluster can be diagnosed using con-
ventional diagnostic tools and methods. For proper
diagnosis of the instrument cluster circuitry that con-
trols the fuel gauge, a diagnostic scan tool is
required. Refer to the appropriate diagnostic infor-
mation.
LOW OIL LEVEL INDICATOR
DESCRIPTION
A low oil level indicator is standard equipment on
all instrument clusters. The low oil level indicator is
located near the lower edge of the instrument cluster,
to the left of the multi-function indicator display. The
low oil level indicator consists of the International
Control and Display Symbol icon for ªEngine Oilº
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. 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 translu-
cent outer layer of the overlay when the indicator is
illuminated from behind by the LED, which is sol-
dered onto the instrument cluster electronic circuit
board. The low oil level indicator is serviced as a unit
with the instrument cluster.
OPERATION
The low oil level indicator gives an indication to
the vehicle operator when the engine oil level is low.
This indicator is controlled by a transistor on the
instrument cluster electronic circuit board based
upon cluster programming and electronic messages
received by the cluster from the Engine Control Mod-
ule (ECM) over the Controller Area Network (CAN)
data bus. The low oil level indicator Light Emitting
Diode (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 toground by the instrument cluster transistor. The
instrument cluster will turn on the low oil level indi-
cator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the low oil level indicator
is illuminated for about two seconds as a bulb test.
²Engine Oil Level Low Message- Once the
engine has been started, each time the cluster
receives a message from the ECM indicating that the
engine oil level is at or near the ªMinimumº mark on
the dipstick, the low oil level indicator is illuminated.
The indicator remains illuminated briefly at first, but
will remain illuminated for longer periods as subse-
quent messages indicate that the oil level has
dropped further. Eventually, the indicator will
remain illuminated solid until the engine oil level is
corrected, or until the ignition switch is turned to the
Off position, whichever occurs first.
The instrument cluster also supplements the oil
level indicator by displaying an engine oil icon along
with alpha-numeric messages in the multi-function
indicator Liquid Crystal Display (LCD) advising the
vehicle operator how much oil is required to correct
the engine oil level, and when the ªMaximumº engine
oil level has been exceeded. See the owner's manual
in the vehicle glove box for more information on this
feature.
The ECM continually monitors the engine oil level
and temperature sensor to determine the engine oil
level. The ECM then sends the proper engine oil
level messages to the instrument cluster. If the
instrument cluster turns on the indicator after the
bulb test, even after the engine oil level is sufficient,
it may indicate that the engine or the engine oiling
system requires service. For proper diagnosis of the
engine oil level and temperature sensor, the ECM,
the CAN data bus, or the electronic message inputs
to the instrument cluster that control the low oil
level indicator, a diagnostic scan tool is required.
Refer to the appropriate diagnostic information.
MAINTENANCE INDICATOR
DESCRIPTION
An Active Service SYSTem (ASSYST) engine oil
maintenance indicator is optional equipment on all
instrument clusters. In vehicles so equipped, a sec-
ond, dedicated ASSYST microprocessor is integral to
the cluster electronic circuit board. The ASSYST indi-
cations are displayed and can be toggled with the
clock indication on the right side of the multi-func-
tion indicator Liquid Crystal Display (LCD) located
near the lower edge of the instrument cluster,
directly below the speedometer. The ASSYST displays
include numeric values combined with several icons
to indicate actual engine oil level, and reminders in
time (days) or distance (miles or kilometers) until the
8J - 20 INSTRUMENT CLUSTERVA

The ECM continually monitors the fuel and emis-
sions system circuits and sensors to decide whether
the system is in good operating condition. The ECM
then sends the proper lamp-on or lamp-off messages
to the instrument cluster. If the instrument cluster
turns on the MIL after the bulb test, it may indicate
that a malfunction has occurred and that the fuel
and emissions systems may require service. For
proper diagnosis of the fuel and emissions systems,
the ECM, the CAN data bus, or the electronic mes-
sage inputs to the instrument cluster that control the
MIL, a diagnostic scan tool is required. Refer to the
appropriate diagnostic information.
MULTI - FUNCTION INDICA-
TOR
DESCRIPTION
A multi-function indicator is standard equipment
on all instrument clusters. The multi-function indica-
tor is located near the lower edge of the instrument
cluster, directly below the speedometer. The multi-
function indicator consists of a Liquid Crystal Dis-
play (LCD) unit and four push button-controlled
switches that are soldered onto the instrument clus-
ter electronic circuit board. The LCD is visible
through a large rectangular cutout in the instrument
cluster overlay, while the four switch push buttons
extend through a black plastic switch bezel located
on the cluster lens directly below the LCD. The four
multi-function indicator push buttons allow the vehi-
cle operator to configure and adjust several of the
display features. The buttons are labeled from left to
right: ªmiº (miles) or ªkmº (kilometers), an icon
depicting an analog clock face (clock), ª2º (minus),
and ª+º (plus).
The multi-function indicator LCD displays both
alpha-numeric characters and numerous icons to pro-
vide information to the vehicle operator. The indica-
tions of the multi-function indicator are not visible
when the LCD is not illuminated. When illuminated
the indications appear as dark characters and icons
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 concert with the cluster general illumina-
tion lighting using the ª+º (plus) and ª2º (minus)
multi-function indicator push buttons. The multi-
function indicator LCD unit and push button
switches are serviced as a unit with the instrument
cluster.
OPERATION
The multi-function indicator has several display
capabilities including odometer, trip odometer, clock,engine oil level data, gear selector indicator
(PRNDL), certain diagnostic information and, on
vehicles so equipped, an optional Active Service SYS-
Tem (ASSYST) engine oil maintenance indicator and
an optional outside ambient temperature indicator.
The multi-function indicator is completely controlled
by the instrument cluster logic circuit, and that logic
will allow this indication to be viewed whenever the
multi-function indicator Liquid Crystal Display
(LCD) is activated. Therefore, the indicator remains
functional regardless of the ignition switch position.
With the ignition switch in the Off or Accessory posi-
tions and the key removed from the ignition lock cyl-
inder, the display is activated when the park lamps
are turned On or, for about thirty seconds after any
one of the multi-function indicator switch push but-
tons is depressed. Otherwise, the display unit is
active for about thirty seconds after the key is
inserted into the ignition lock cylinder, and inactive
about thirty seconds after the key is removed from
the ignition lock cylinder.
The multi-function indicator ªmiº (miles) or
ªkmº(kilometers) switch push button is used to con-
trol the odometer/trip odometer display modes. The
multi-function indicator clock switch push button is
used to control the clock/outside temperature display
modes. The multi-function indicator ª+º (plus) and
ª2º (minus) switch push buttons are used to adjust
the cluster general illumination dimming level, the
clock, and other cluster settings. See the owner's
manual in the vehicle glove box for more information
on the features, use, operation and setting proce-
dures for the various standard and optional multi-
function indicator displays.
Proper testing of the multi-function indicator LCD
unit, the CAN data bus and the electronic data bus
message inputs to the instrument cluster that control
some of the multi-function indicator functions
requires the use of a diagnostic scan tool. Refer to
the appropriate diagnostic information. Additional
details for the odometer/trip odometer, the clock, the
gear selector indicator, the ambient temperature indi-
cator and the ASSYST warning and reminder func-
tions of the multi-function indicator may be found
elsewhere in this service information.
ODOMETER
DESCRIPTION
An odometer and trip odometer are standard
equipment in all instrument clusters. The odometer
and trip odometer values are displayed on the left
side of the multi-function indicator Liquid Crystal
Display (LCD). The LCD is soldered onto the cluster
electronic circuit board and is visible through a win-
dow with a clear lens located near the lower edge of
8J - 22 INSTRUMENT CLUSTERVA