Page 185 of 1232

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
Page 186 of 1232

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)
Page 187 of 1232

nosed using conventional diagnostic tools and meth-
ods. For proper diagnosis of the instrument cluster
circuitry that controls the fuel gauge, a DRBIIItscan
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 gearselector 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 DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
HIGH BEAM INDICATOR
DESCRIPTION
A high beam indicator is standard equipment on
all instrument clusters. The high beam indicator is
located near the lower edge of the instrument cluster,
to the left of the multi-function indicator display. The
high beam indicator consists of the International
Control and Display Symbol icon for ªHigh Beamº
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
blue Light Emitting Diode (LED) behind the cutout
in the opaque layer of the overlay causes the icon to
appear silhouetted against a blue field 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 high beam indicator is serviced as a
unit with the instrument cluster.
OPERATION
The high beam indicator gives an indication to the
vehicle operator whenever the headlamp high beams
are illuminated. This indicator is controlled by a
transistor on the instrument cluster circuit board
based upon cluster programming and a hard wired
input from the multi-function switch. The high beam
indicator Light Emitting Diode (LED) is completely
controlled by the instrument cluster logic circuit, and
that logic will allow this indicator to operate when-
ever the instrument cluster receives battery current
on the fused B(+) circuit. Therefore, the LED can be
illuminated regardless of the ignition switch position.
The LED only illuminates when it is provided a path
to ground by the instrument cluster transistor. The
instrument cluster will turn on the high beam indi-
cator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the high beam indicator is
illuminated by the cluster for about two seconds as a
bulb test.
VAINSTRUMENT CLUSTER 8J - 17
FUEL GAUGE (Continued)
Page 188 of 1232

²High Beams On Input- Each time the cluster
receives a high beam headlamps-on input from the
multi-function switch, the high beam indicator will
be illuminated. The indicator remains illuminated
until the cluster receives a high beam headlamps-off
input from the multi-function switch.
The instrument cluster continually monitors the
multi-function switch input to determine whether the
high beam indicator should be illuminated or extin-
guished. The multi-function switch and the multi-
function switch input circuit to the instrument
cluster can be diagnosed using conventional diagnos-
tic tools and methods. For proper diagnosis of the
instrument cluster circuitry that controls the high
beam indicator, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
LOW FUEL INDICATOR
DESCRIPTION
A low fuel indicator is standard equipment on all
instrument clusters. The low fuel indicator is located
directly below the low end of the fuel gauge scale.
The low fuel indicator consists of a small triangular
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 triangle 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 low fuel indicator is serviced as a
unit with the instrument cluster.
OPERATION
The low fuel indicator gives an indication to the
vehicle operator when the level of fuel in the fuel
tank becomes 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 fuel level sen-
sor in the fuel tank. The low fuel 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 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 low fuel indi-
cator for the following reasons:²Bulb Test- Each time the ignition switch is
turned to the On position the low fuel indicator is
illuminated for about two seconds as a bulb test.
²Fuel Level Sensor Input- Each time the clus-
ter receives an input from the fuel level sensor indi-
cating that the fuel level has reached about 12 liters
(3 gallons) or less, the low fuel indicator is illumi-
nated. The indicator remains illuminated until the
cluster receives an input from the fuel level sensor
indicating that the fuel level is above 12 liters (3 gal-
lons), or until the ignition switch is turned to the Off
position, whichever occurs first.
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-
nosed using conventional diagnostic tools and meth-
ods. For proper diagnosis of the instrument cluster
circuitry that controls the fuel gauge, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
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-
8J - 18 INSTRUMENT CLUSTERVA
HIGH BEAM INDICATOR (Continued)
Page 189 of 1232

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 to
ground 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 oper-
ator 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 DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
MAINTENANCE INDICATOR
DESCRIPTION
An Active Service SYSTem (ASSYST) engine oil main-
tenance indicator is optional equipment on all instru-
ment clusters. In vehicles so equipped, a second,dedicated ASSYST microprocessor is integral to the
cluster electronic circuit board. The ASSYST indications
are displayed and can be toggled with the clock indica-
tion 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 speed-
ometer. 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 next required engine oil mainte-
nance is anticipated. ASSYST also provides several
audible indications using the electronic tone generator
on the instrument cluster circuit board to supplement
these visual displays.
The indications of the ASSYST engine oil mainte-
nance indicator are not visible when the LCD is not illu-
minated. When illuminated, the ASSYST 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 illumination lighting using the ª+º (plus)
and ª2º (minus) multi-function indicator push buttons.
The ASSYST engine oil maintenance indicator is ser-
viced as a unit with the instrument cluster.
OPERATION
The ASSYST engine oil maintenance indicator micro-
processor uses numerous criteria besides time and mile-
age to evaluate vehicle maintenance requirements. Time
data is taken from the electronic digital clock integral to
the instrument cluster. Vehicle distance data is obtained
from the Controller Antilock Brake (CAB) over the Con-
troller Area Network (CAN) data bus. Coolant tempera-
ture, engine oil temperature, engine oil level, engine oil
quality, engine speed, and engine load data are obtained
from the Engine Control Module (ECM) over the CAN
data bus. Using all of the available data and internal
programming, the ASSYST microprocessor then calcu-
lates the estimated time and distance to the next
required engine oil maintenance interval. The ASSYST
uses the multi-function indicator LCD to display that
data and, when necessary, issues audible alerts to the
vehicle operator through the electronic tone generator
on the cluster circuit board.
See the owner's manual in the vehicle glove box for
more information on the features, use, operation and
resetting procedures for the ASSYST maintenance
computer. Proper diagnosis and testing of the
ASSYST engine oil maintenance computer, the CAN
data bus and the electronic data bus message inputs
to the EMIC that are used by the ASSYST computer
for its calculations requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
VAINSTRUMENT CLUSTER 8J - 19
LOW OIL LEVEL INDICATOR (Continued)
Page 190 of 1232

MALFUNCTION INDICATOR
LAMP (MIL)
DESCRIPTION
A Malfunction Indicator Lamp (MIL) is standard
equipment on all instrument clusters. The MIL is
located near the lower edge of the instrument cluster, to
the right of the multi-function indicator display. The
MIL consists of the International Control and Display
Symbol icon for ªEngineº imprinted within a rectangu-
lar 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 MIL is serviced as a unit with
the instrument cluster.
OPERATION
The Malfunction Indicator Lamp (MIL) gives an indi-
cation to the vehicle operator when the Engine Control
Module (ECM) has recorded a Diagnostic Trouble Code
(DTC) for an On-Board Diagnostics II (OBDII) emissions-
related circuit or component malfunction. The MIL is
controlled by a transistor on the instrument cluster cir-
cuit board based upon cluster programming and elec-
tronic messages received by the cluster from the ECM
over the Controller Area Network (CAN) data bus. The
MIL 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 posi-
tion. 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 MIL for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the MIL is illuminated as a
bulb test. The indicator will remain illuminated until
the engine is started, or until the ignition switch is
turned to the Off position, whichever occurs first.
²MIL Lamp-On Message- Each time the clus-
ter receives a MIL lamp-on message from the ECM,
the indicator will be illuminated. The indicator will
remain illuminated until the detected fault is
repaired, or until the ignition switch is turned to the
Off position, whichever occurs first. For more infor-
mation on the ECM and the DTC set and reset
parameters, (Refer to 25 - EMISSIONS CONTROL -
OPERATION).²Communication Error- If the cluster receives
no lamp-on or lamp-off message from the ECM, the
MIL is illuminated by the instrument cluster. The
indicator remains controlled and illuminated by the
cluster until a valid lamp-on or lamp-off message is
received from the ECM.
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 DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
MULTI-FUNCTION INDICATOR
DESCRIPTION
A multi-function indicator is standard equipment on
all instrument clusters. The multi-function indicator is
located near the lower edge of the instrument cluster,
directly below the speedometer. The multi-function indi-
cator consists of a Liquid Crystal Display (LCD) unit
and four push button-controlled switches that are sol-
dered onto the instrument cluster 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 vehicle operator to configure and adjust sev-
eral 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 indications
of the multi-function indicator are not visible when the
LCD is not illuminated. When illuminated the indica-
tions 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 illumination 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.
8J - 20 INSTRUMENT CLUSTERVA
Page 191 of 1232

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 DRBIIItscan tool. Refer to the
appropriate diagnostic information. Additional details
for the odometer/trip odometer, the clock, the gear
selector indicator, the ambient temperature indicator
and the ASSYST warning and reminder functions 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 leftside 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
the instrument cluster, directly below the speedome-
ter. However, the odometer and trip odometer infor-
mation are not displayed simultaneously. The ªmiº
(miles) or ªkmº (kilometers) switch on the instrument
cluster circuit board toggles the display between
odometer and trip odometer modes by depressing the
switch push button that extends through the lower
edge of the cluster lens, directly below the multi-
function indicator LCD.
The odometer and trip odometer information is
stored in the instrument cluster memory. This infor-
mation can be increased when the proper inputs are
provided to the instrument cluster, but the informa-
tion cannot be decreased. The odometer can display
values up to 999,999 kilometers (999,999 miles). The
odometer latches at these values, and will not roll
over to zero. The trip odometer can display values up
to 999.9 kilometers (999.9 miles) before it rolls over
to zero. The odometer display does not have a deci-
mal point and will not show values less than a full
unit (kilometer or mile), while the trip odometer dis-
play does have a decimal point and will show tenths
of a unit (kilometer or mile). The unit of measure
(kilometers or miles) for the odometer and trip odom-
eter display is imprinted on the cluster overlay below
the left end of the LCD. The unit of measure for the
instrument cluster odometer/trip odometer is selected
at the time that it is manufactured, and cannot be
changed.
The indications of the odometer/trip odometer are
not visible when the LCD is not illuminated. When
illuminated the indications appear as dark charac-
ters silhouetted against an amber field. When the
exterior lighting is turned Off, the display is illumi-
nated at maximum brightness. When the exterior
lighting is turned On the display illumination level
can be adjusted in concert with the cluster general
illumination lighting using the plus and minus multi-
function indicator push buttons. The odometer has a
ªRental Carº mode, which will activate the multi-
function indicator LCD and illuminate the odometer
information for about thirty seconds after one of the
multi-function indicator push buttons is momentarily
depressed, or after the key is inserted into the igni-
tion switch lock cylinder with the ignition switch in
the Off position.
The odometer/trip odometer and the miles/kilome-
ters switch, and the miles/kilometers switch push
button are serviced as a unit with the instrument
cluster.
VAINSTRUMENT CLUSTER 8J - 21
MULTI-FUNCTION INDICATOR (Continued)
Page 192 of 1232

OPERATION
The odometer and trip odometer give an indication
to the vehicle operator of the distance the vehicle has
traveled. This indicator is controlled by the instru-
ment cluster circuitry based upon cluster program-
ming and electronic messages received by the cluster
from the Controller Anti-lock Brake (CAB) over the
Controller Area Network (CAN) data bus. The odom-
eter and trip odometer information is displayed by
the multi-function indicator Liquid Crystal Display
(LCD). The LCD will display the odometer informa-
tion whenever it is activated, and will display the
last previously selected odometer or trip odometer
information when the ignition switch is turned to the
On position. The instrument cluster circuitry controls
the LCD and provides the following features:
²Odometer/Trip Odometer Display Toggling-
Actuating the multi-function indicator ªmiº (miles) or
ªkmº (kilometers) switch push button momentarily
with the LCD illuminated will toggle the display
between the odometer and trip odometer information.
Each time the LCD is illuminated with the ignition
switch in the On or Start positions, the display will
automatically return to the last mode previously
selected (odometer or trip odometer).
²Trip Odometer Reset- When the multi-func-
tion indicator ªmiº (miles) or ªkmº (kilometers) switch
push button is pressed and held for longer than
about two seconds, the trip odometer will be reset to
000.0 kilometers (miles). The LCD must be display-
ing the trip odometer information in order for the
trip odometer information to be reset.
The CAB continually monitors the vehicle speed
pulse information received from the four wheel speed
sensors, then sends the proper distance messages to
the instrument cluster. For proper diagnosis of the
wheel speed sensors, the CAB, the CAN data bus, or
the electronic message inputs to the instrument clus-
ter that control the odometer/trip odometer, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
SEATBELT INDICATOR
DESCRIPTION
A seatbelt indicator is standard equipment on all
instrument clusters. The seatbelt indicator is located
near the lower edge of the instrument cluster, to the
right of the multi-function indicator display. The
seatbelt indicator consists of the International Con-
trol and Display Symbol icon for ªSeat Beltº
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 redLight 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 seatbelt indicator is serviced as a unit
with the instrument cluster.
OPERATION
The seatbelt indicator gives an indication to the
vehicle operator of the status of the driver side front
seat belt. This indicator is controlled by a transistor
on the instrument cluster circuit board based upon
cluster programming and a hard wired input received
from the seat belt switch on the driver side front seat
belt. The seatbelt 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 igni-
tion 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 seatbelt indicator for the fol-
lowing reasons:
²Seatbelt Reminder Function- Each time the
cluster detects that the ignition switch has been
turned to the On position the seatbelt indicator will
be illuminated as a reminder for about six seconds,
or until the ignition switch is turned to the Off posi-
tion, whichever occurs first. This reminder function
will occur regardless of the status of the input
received by the cluster from the driver side front seat
belt switch.
²Driver Side Front Seat Belt Switch Input-
Following the seatbelt reminder function, each time
the cluster detects ground on the seatbelt indicator
driver circuit (seat belt switch closed = seatbelt
unbuckled) with the ignition switch in the On posi-
tion, the seatbelt indicator will be illuminated. The
seatbelt indicator remains illuminated until the seat
belt switch input to the cluster is an open circuit
(seat belt switch open = seatbelt buckled), or until
the ignition switch is turned to the Off position,
whichever occurs first.
²Airbag Indicator Malfunction- Following the
seatbelt reminder function, each time the cluster
detects a malfunction in the airbag (SRS) indicator or
the airbag indicator circuit, the cluster will flash the
seatbelt indicator on and off. The cluster will con-
tinue to flash the seatbelt indicator until the airbag
indicator circuit fault is resolved, or until the ignition
switch is turned to the Off position, whichever occurs
first.
8J - 22 INSTRUMENT CLUSTERVA
ODOMETER (Continued)