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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
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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.
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 instrumentcluster 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 diagnostic scan 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
VAINSTRUMENT CLUSTER 8J - 19
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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
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next required engine oil maintenance is anticipated.
ASSYST also provides several audible indications
using the electronic tone generator on the instrument
cluster circuit board to supplement these visual dis-
plays.
The indications of the ASSYST engine oil mainte-
nance indicator are not visible when the LCD is not
illuminated. When illuminated, the ASSYST 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 con-
cert with the cluster general illumination lighting
using the ª+º (plus) and ª2º (minus) multi-function
indicator push buttons. The ASSYST engine oil main-
tenance indicator is serviced as a unit with the
instrument cluster.
OPERATION
The ASSYST engine oil maintenance indicator
microprocessor uses numerous criteria besides time
and mileage to evaluate vehicle maintenance require-
ments. Time data is taken from the electronic digital
clock integral to the instrument cluster. Vehicle dis-
tance data is obtained from the Controller Antilock
Brake (CAB) over the Controller Area Network
(CAN) data bus. Coolant temperature, 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 cal-
culates 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 diagnostic
scan tool. Refer to the appropriate diagnostic infor-
mation.
MALFUNCTION INDICATOR
LAMP (MIL)
DESCRIPTION
A Malfunction Indicator Lamp (MIL) is standard
equipment on all instrument clusters. The MIL islocated 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
rectangular cutout in the opaque layer of the instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
ible 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 trans-
lucent 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 MIL is serviced as a unit with the instru-
ment cluster.
OPERATION
The Malfunction Indicator Lamp (MIL) gives an
indication 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 mal-
function. The MIL is controlled by a transistor on the
instrument cluster circuit board based upon cluster
programming and electronic 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 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 MIL for the fol-
lowing 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.
VAINSTRUMENT CLUSTER 8J - 21
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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
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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.
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 theController 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 diag-
nostic scan tool is required. Refer to the appropriate
diagnostic information.
PARK BRAKE INDICATOR
DESCRIPTION
A park brake indicator is standard equipment on
all instrument clusters. The park brake indicator is
located near the lower edge of the instrument cluster,
to the left of the multi-function indicator display. The
park brake indicator consists of stencil-like cutout of
the word ªPARKº in the opaque layer of the instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
ible when it is not illuminated. A red Light Emitting
Diode (LED) behind the cutout in the opaque layer of
the overlay causes the ªPARKº text to appear in red
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
electronic circuit board. The park brake indicator is
serviced as a unit with the instrument cluster.
VAINSTRUMENT CLUSTER 8J - 23
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OPERATION
The park brake indicator gives an indication to the
vehicle operator when the parking brake is applied.
This indicator is controlled by a transistor on the
instrument cluster circuit board based upon a hard
wired input from the park brake switch. The park
brake indicator Light Emitting Diode (LED) is com-
pletely controlled by the instrument cluster logic cir-
cuit, 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 park brake indicator for the following
reasons:
²Park Brake Switch Input- Each time the
cluster detects ground on the park brake indicator
signal circuit (park brake switch closed = park brake
applied or not fully released) while the ignition
switch is in the On position, the brake indicator is
illuminated. The indicator remains illuminated until
the brake signal indicator input to the cluster is an
open circuit (park brake switch open = park brake
fully released), or until the ignition switch is turned
to the Off position, whichever occurs first.
The park brake switch on the park brake pedal
mechanism provides a hard wired ground input to
the instrument cluster circuitry through the park
brake indicator signal circuit whenever the park
brake is applied or not fully released. The two
switches are connected in series between ground and
the instrument cluster. The park brake switch and
the input circuit to the instrument cluster can be
diagnosed using conventional diagnostic tools and
methods. For proper diagnosis of the instrument
cluster circuitry that controls the park brake indica-
tor, a diagnostic scan tool is required. Refer to the
appropriate 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 red
Light Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the icon to appearsilhouetted 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.
The instrument cluster continually monitors the
status of the driver side front seat belt switch and
the airbag indicator circuit to determine the proper
seatbelt indicator response. The seat belt switch is
8J - 24 INSTRUMENT CLUSTERVA
Page 944 of 2305

connected in series between the instrument cluster
and ground. The seat belt switch and the seatbelt
indicator driver circuit to the instrument cluster can
be diagnosed using conventional diagnostic tools and
methods. For proper diagnosis of the ACM, the air-
bag (SRS) indicator, or the instrument cluster cir-
cuitry that controls the seatbelt indicator, a
diagnostic scan tool is required. Refer to the appro-
priate diagnostic information.
SPEEDOMETER
DESCRIPTION
A speedometer is standard equipment on all instru-
ment clusters. The speedometer is located in the cen-
ter of the instrument cluster. The speedometer
consists of a movable gauge needle or pointer con-
trolled by the instrument cluster circuitry and a fixed
210 degree primary outer scale on the gauge dial face
that reads left-to-right either from ª0º to ª100º miles-
per-hour, or from ª0º to ª180º kilometers-per-hour,
depending upon the market for which the vehicle is
manufactured. Each version also has a secondary
inner scale on the gauge dial face that provides the
equivalent opposite units from the primary scale.
Text appearing on the cluster overlay near the left
end of each scale abbreviates the unit of measure,
either ªmphº or ªkm/hº.
The speedometer graphics are white against a
black field, making them clearly visible within the
instrument 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
illumination is provided by Light Emitting Diode
(LED) units soldered onto the instrument cluster
electronic circuit board. The speedometer is serviced
as a unit with the instrument cluster.
OPERATION
The speedometer gives an indication to the vehicle
operator of the vehicle road speed. This gauge is con-
trolled by the instrument cluster circuit board based
upon cluster programming and electronic messages
received by the cluster from the Controller Anti-lock
Brake (CAB) over the Controller Area Network
(CAN) data bus. The speedometer is an air core mag-
netic unit that receives battery current on the instru-
ment 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:²Vehicle Speed Message- Each time the clus-
ter receives a vehicle speed message from the CAB it
will calculate the correct vehicle speed reading and
position the gauge needle at that relative speed posi-
tion on the gauge scale. The gauge needle will con-
tinue to be positioned at the actual vehicle speed
position on the gauge scale until the ignition switch
is turned to the Off position.
²Communication Error- If the cluster fails to
receive a speedometer message, it will hold the gauge
needle at the last indication for about three seconds,
or until the ignition switch is turned to the Off posi-
tion, whichever occurs first. After three seconds, the
gauge needle will return to the left end of the gauge
scale.
The CAB continually monitors the four wheel
speed sensors to determine the vehicle road speed.
The CAB then sends the proper vehicle speed mes-
sages 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 instru-
ment cluster that control the speedometer, a diagnos-
tic scan tool is required. Refer to the appropriate
diagnostic information.
TACHOMETER
DESCRIPTION
A tachometer is standard equipment on all instru-
ment clusters. The tachometer is located to the left of
the speedometer, to the left of center in the instru-
ment cluster. The tachometer consists of a movable
gauge needle or pointer controlled by the instrument
cluster circuitry and a fixed 45 degree scale on the
gauge dial face that reads left-to-right from ª0º to ª7º.
The text ªrpm X 1000º imprinted on the cluster over-
lay near the left end of the gauge scale identifies that
each number on the tachometer scale is to be multi-
plied by 1000 rpm.
The tachometer 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 tachometer is serviced as a unit
with the instrument cluster.
OPERATION
The tachometer gives an indication to the vehicle
operator of the engine speed. This gauge is controlled
by the instrument cluster circuit board based upon
cluster programming and electronic messages
VAINSTRUMENT CLUSTER 8J - 25