2002 JEEP LIBERTY Lights

economy, and/or trip odometer data has been reset.
The CMTC uses internal programming, hard wired
inputs from the U.S./Metric and Reset switches, and
electronic messages received from the Body Control
Module (BCM) to determine the proper reset mes-
sages to send to the EMIC.
²Door Ajar Warning- The EMIC chime tone
generator will generate a single ªbong-likeº chime
tone when the ignition switch is in the On position,
and electronic messages are received over the PCI
data bus from the Body Control Module (BCM) indi-
cating that the status of any door ajar input has
changed from closed to not closed, and from the PCM
indicating that the vehicle is moving. The BCM uses
internal programming, and hard wired inputs from
the door ajar switches and the ignition switch to
determine the proper door ajar switch messages to
send to the EMIC. The PCM uses internal program-
ming and a hard wired vehicle speed pulse input
received from the BCM to determine the proper vehi-
cle distance messages to send to the EMIC.
²Electrical System Voltage Low or High
Warning- Each time the ignition switch is turned to
the On position, the EMIC chime tone generator will
generate a single ªbong-likeº chime tone the first
time an electronic message is received over the PCI
data bus from the PCM requesting ªChargingº indi-
cator illumination. This warning would indicate that
the monitored electrical system voltage is either too
low or too high. This warning will only occur once
during an ignition cycle. The PCM uses internal pro-
gramming and hard wired inputs from the electrical
and charging systems to determine the proper
ªChargingº indicator messages to send to the EMIC.
²Engine Coolant Temperature High Warning
- Each time the ignition switch is turned to the On
position, the EMIC chime tone generator will gener-
ate ªbong-likeº chime tones the first time an elec-
tronic message is received over the PCI data bus
from the PCM indicating that the engine coolant
temperature is too high. This chime will sound for
five consecutive single tones, unless an electronic
message is received from the PCM indicating that
the engine coolant temperature is not too high, or
unless the ignition switch is turned to the Off posi-
tion before the five single tones have completed. The
PCM uses internal programming and a hard wired
input from the engine coolant temperature sensor to
determine the proper engine coolant temperature
messages to send to the EMIC.
²Engine Oil Pressure Low Warning- Each
time the ignition switch is turned to the On position,
the EMIC chime tone generator will generate a sin-
gle ªbong-likeº chime tone the first time three
sequential sets of electronic messages are received
over the PCI data bus from the PCM indicating thatthe engine oil pressure is too low with the engine
running. The PCM uses internal programming and
hard wired inputs from the oil pressure sensor and
the crankshaft position sensor to determine the
proper oil pressure and engine speed messages to
send to the EMIC.
²Fasten Seat Belt Warning- Each time the
ignition switch is turned to the On position, the
EMIC chime tone generator will generate repetitive
ªbong-likeº chime tones at a slow rate the first time
an electronic message is received over the PCI data
bus from the ACM requesting ªSeatbeltº indicator
illumination. The ACM uses internal programming
and hard wired inputs from the driver side front seat
belt switch and the ignition switch to determine that
the driver side front seat belt is not fastened with
the ignition switch in the On position. These chimes
will continue to sound for a duration of about six sec-
onds each time the ignition switch is turned to the
On position, or until the driver side front seat belt is
fastened, whichever occurs first. This audible warn-
ing occurs independent of the visual warning pro-
vided by the EMIC ªSeatbeltº indicator.
²Gate Ajar Warning- The EMIC chime tone
generator will generate a single ªbong-likeº chime
tone when the ignition switch is in the On position,
and electronic messages are received over the PCI
data bus from the BCM indicating that the status of
the tailgate ajar input has changed from closed to
not closed, and from the PCM indicating that the
vehicle is moving. The BCM uses internal program-
ming, and hard wired inputs from the tailgate ajar
switch and the ignition switch to determine the
proper tailgate ajar switch messages to send to the
EMIC. The PCM uses internal programming and a
hard wired vehicle speed pulse input received from
the BCM to determine the proper vehicle distance
messages to send to the EMIC.
²Glass Ajar Warning- The EMIC chime tone
generator will generate a single ªbong-likeº chime
tone when the ignition switch is in the On position,
and electronic messages are received over the PCI
data bus from the BCM indicating that the status of
the rear flip-up glass ajar input has changed from
closed to not closed, and from the PCM indicating
that the vehicle is moving. The BCM uses internal
programming, and hard wired inputs from the flip-up
glass ajar switch and the ignition switch to deter-
mine the proper flip-up glass ajar switch messages to
send to the EMIC. The PCM uses internal program-
ming and a hard wired vehicle speed pulse input
received from the BCM to determine the proper vehi-
cle distance messages to send to the EMIC.
²Head/Park/Fog Lights-On Warning- The
EMIC chime tone generator will generate repetitive
ªbong-likeº chime tones at a fast rate when the igni-
KJCHIME/BUZZER 8B - 3
CHIME WARNING SYSTEM (Continued)

tion switch is in any position except On, and elec-
tronic messages are received over the PCI data bus
from the BCM indicating that the exterior lights are
On with the ignition switch in any position except
On, and the status of the driver side front door is not
closed. The BCM uses internal programming and
hard wired inputs from the left (lighting) control
stalk of the multi-function switch, the ignition
switch, and the driver side front door ajar switch to
determine the proper messages to send to the EMIC.
These chimes will continue to sound until the exte-
rior lighting is turned Off, until the ignition switch is
turned to the On position, or until the status of the
driver side front door ajar input changes from not
closed to closed, whichever occurs first.
²Key-In-Ignition Warning- The EMIC chime
tone generator will generate repetitive ªbong-likeº
chime tones at a fast rate when the ignition switch is
in any position except On, and electronic messages
are received over the PCI data bus from the BCM
indicating that the key is in the ignition lock cylinder
with the ignition switch in any position except On,
and the driver side front door is not closed. The BCM
internal programming and hard wired inputs from
the key-in ignition circuitry of the ignition switch,
the ignition switch, and the driver side front door
ajar switch to determine the proper messages to send
to the EMIC. These chimes will continue to sound
until the key is removed from the ignition lock cylin-
der, until the ignition switch is turned to the On
position, or until the status of the driver side front
door ajar input changes from not closed to closed,
whichever occurs first.
²Low Coolant Warning- On vehicles equipped
with a diesel engine, the EMIC chime tone generator
will generate a single ªbong-likeº chime tone when
the ignition switch is first turned to the On position
and a hard wired input from the engine coolant level
sensor to the EMIC indicates that the coolant level is
low for more than about one-quarter second. Any
time after the ignition switch is first turned to the
On position, the EMIC uses internal programming to
check the status of the engine coolant level sensor
inputs about once every second, then adjusts an
internal counter up or down based upon the status of
this input. When the counter accumulates thirty
inputs indicating that the coolant level is low, a sin-
gle chime tone is sounded. This strategy is intended
to reduce the effect that coolant sloshing within the
coolant reservoir can have on reliable chime warning
operation. This warning will only occur once during
an ignition cycle.
²Low Fuel Warning- Each time the ignition
switch is turned to the On position, the EMIC chime
tone generator will generate a single ªbong-likeº
chime tone the first time an electronic message isreceived over the PCI data bus from the PCM
requesting ªLow Fuelº indicator illumination. The
chime will only occur a second time during the same
ignition cycle if another electronic message has been
received from the PCM indicating that there is an
increase in the fuel level equal to about 3 liters (0.8
gallon), then a subsequent electronic message from
the PCM requests ªLow Fuelº indicator illumination.
This strategy combined with filtering performed by
the internal programming of the PCM on the fuel
tank sending unit input is intended to reduce the
possibility of fuel sloshing within the fuel tank caus-
ing multiple low fuel warning chimes during a given
ignition cycle. The EMIC will also respond with the
low fuel warning chime when electronic fuel level
messages are received from the PCM indicating that
the hard wired input to the PCM from the fuel tank
sending unit is an open circuit (greater than full), or
a short circuit (less than empty).
²Low Washer Fluid Warning- The EMIC
chime tone generator will generate a single ªbong-
likeº chime tone when the ignition switch is turned
to the On position and a hard wired input from the
washer fluid level switch to the EMIC indicates the
washer fluid is low for more than about one-quarter
second. Any time after the ignition switch is first
turned to the On position, the EMIC uses internal
programming to check the status of the washer fluid
level switch inputs about once every second, then
adjusts an internal counter up or down based upon
the status of this input. When the counter accumu-
lates thirty inputs indicating that the washer fluid
level is low, a single chime tone is sounded. This
strategy is intended to reduce the effect that fluid
sloshing within the washer reservoir can have on
reliable chime warning operation. This warning will
only occur once during an ignition cycle.
²Overspeed Warning- The EMIC chime tone
generator will generate repetitive ªbong-likeº chime
tones at a slow rate when the ignition switch is in
the On position, and an electronic message received
over the PCI data bus from the PCM indicates that
the vehicle speed is over a programmed speed value.
The PCM uses internal programming and distance
pulse information received over a hard wired vehicle
speed pulse input from the BCM to determine the
proper vehicle speed messages to send to the EMIC.
The BCM uses an internally programmed electronic
pinion factor and a hard wired input from the rear
wheel speed sensor to calculate the proper distance
pulse information to send to the PCM. The electronic
pinion factor represents the proper tire size and axle
ratio information for the vehicle. These chimes will
continue to sound until the vehicle speed messages
are below the programmed speed value, or until the
ignition switch is turned to the Off position, which-
8B - 4 CHIME/BUZZERKJ
CHIME WARNING SYSTEM (Continued)

REAR WINDOW DEFOGGER
SWITCH
DESCRIPTION
The rear window defogger switch is installed in the
instrument panel HVAC contol head assembly. The
momentary-type switch provides a hard-wired ground
signal to the HVAC control head each time it is
depressed. The instrument cluster rear window
defogger timer and logic circuitry responds by ener-
gizing or de-energizing the rear window defogger
relay.
OPERATION
Energizing the rear window defogger relay pro-
vides electrical current to the rear window defogger
grid and, if the vehicle is so equipped, the outside
rear view mirror heating grids. An amber indicator
lamp in the defogger switch, which lights to indicate
when the defogger system is turned On, is also pow-
ered by the defogger relay output.
The defogger switch illumination lamp and indica-
tor lamp bulbs are serviceable. The defogger switch
cannot be repaired and, if faulty or damaged the
entire HVAC control head assembly must be
replaced.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - REAR WINDOW
DEFOGGER SWITCH
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable. Remove the HVAC control head assembly from
the instrument panel and unplug the defogger switch
wire harness connector-B.
(2) Check for continuity between the ground cir-
cuit cavity of the defogger switch wire harness con-nector and a good ground. There should be
continuity. If OK, go to Step 3. If not OK, repair the
open circuit as required.
(3) Check for continuity between the ground cir-
cuit terminal and the rear window defogger switch
sense circuit terminal on the back of the defogger
switch housing (Fig. 5). There should be momentary
continuity as the defogger switch button is depressed,
and then no continuity. If OK, (Refer to 8 - ELEC-
TRICAL/HEATED GLASS/REAR WINDOW DEFOG-
GER SWITCH - DIAGNOSIS AND TESTING -
INSTRUMENT CLUSTER REAR WINDOW DEFOG-
GER FUNCTION) If not OK, replace the faulty
switch (Fig. 5).
(4) Check switch position continuity between:
CONTACT PINS
1 - OFF LAMPS A-1 - A-7
2 - ON MOMENTARY B-6 - B-8
3 - ILLUMINATION LAMP A-7 - A-1
4 - INDICATOR LAMP B-12 - B-7
Fig. 5 A/C HEATER CONTROL HEAD (Rear View)
1 - A/C HEATER CONTROL HEAD
2 - A/C HEATER CONTROL HEAD LIGHT
3 - REAR WINDOW DEFOGGER SWITCH AND TEMPERATURE
BLEND DOOR- CONNECTOR B (12 PIN)
4 - A/C HEATER CONTROL HEAD LIGHT
5 - MODE SELECT CONTROL
6 - BLOWER SPEED CONTROL- CONNECTOR A (7 PIN)
7 - MOUNTING SCREWS (4)
8G - 8 WINDOW DEFOGGERKJ

indicator will be illuminated for the following rea-
sons:
²VTSS Indication- During the sixteen second
VTA pre-arming function, the BCM will flash the
security indicator on and off repeatedly at a steady,
fast rate to indicate that the VTA is in the process of
arming. Following successful VTA arming, the BCM
flashes the security indicator on and off continuously
at a slower rate to indicate that the VTA is armed.
The security indicator continues flashing at the
slower rate until the VTA is disarmed.
The BCM provides a hard wired ground input to
the instrument cluster circuitry through the VTSS
indicator driver circuit whenever the ignition switch
is in the Off position and the VTA is arming, armed,
or triggered. The VTSS indicator driver circuit
between the BCM and the instrument cluster can be
diagnosed using conventional diagnostic tools and
methods. However, for proper diagnosis of the VTA
and the BCM, or the hard wired inputs to the instru-
ment cluster that control the security indicator, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
SHIFT INDICATOR (TRANSFER
CASE)
DESCRIPTION
DESCRIPTION - PART TIME INDICATOR
A part time indicator is standard equipment on all
instrument clusters. The part time indicator is
located near the lower edge of the tachometer dial
face in the instrument cluster. The part time indica-
tor consists of a stencil-like cutout of the words
ªPART TIMEº 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 ªPART TIMEº text to appear
in amber through the translucent outer layer of the
overlay when it is illuminated from behind by the
LED, which is soldered onto the instrument cluster
electronic circuit board. When the exterior lighting is
turned On, the illumination intensity of the part
time indicator is dimmable, which is adjusted using
the panel lamps dimmer control ring on the left con-
trol stalk of the multi-function switch. The part time
indicator is serviced as a unit with the instrument
cluster.
DESCRIPTION - FULL TIME INDICATOR
A full time indicator is standard equipment on all
instrument clusters, but is only functional on vehi-
cles equipped with the optional Selec-Trac four-wheel
drive system. The full time indicator is located near
the lower edge of the tachometer dial face in the
instrument cluster. The full time indicator consists of
a stencil-like cutout of the words ªFULL TIMEº in
the opaque layer of the instrument cluster overlay.
The dark outer layer of the overlay prevents the indi-
cator from being clearly visible when it is not illumi-
nated. A green Light Emitting Diode (LED) behind
the cutout in the opaque layer of the cluster overlay
causes the ªFULL TIMEº text to appear in green
through the translucent outer layer of the overlay
when it is illuminated from behind by the LED,
which is soldered onto the instrument cluster elec-
tronic circuit board. When the exterior lighting is
turned On, the illumination intensity of the full time
indicator is dimmable, which is adjusted using the
panel lamps dimmer control ring on the left control
stalk of the multi-function switch. The full time indi-
cator is serviced as a unit with the instrument clus-
ter.
DESCRIPTION - FOUR LOW MODE INDICATOR
A four low mode indicator is standard equipment
on all instrument clusters. The four low mode indica-
tor is located above the coolant temperature gauge
and to the right of the speedometer in the instru-
ment cluster. The four low mode indicator consists of
a stencil-like cutout of the words ª4 LO MODEº in
the opaque layer of the instrument cluster overlay.
The dark outer layer of the overlay prevents the indi-
cator from being clearly visible when it is not illumi-
nated. An amber Light Emitting Diode (LED) behind
the cutout in the opaque layer of the overlay causes
the ª4 LO MODEº text to appear in amber through
the translucent outer layer of the overlay when it is
illuminated from behind by the LED, which is sol-
dered onto the instrument cluster electronic circuit
board. The four low mode indicator is serviced as a
unit with the instrument cluster.
OPERATION
OPERATION - PART TIME INDICATOR
The part time indicator gives an indication to the
vehicle operator that a four-wheel drive part time
operating mode of the transfer case is selected. On
vehicles equipped with the standard Command-Trac
four-wheel drive system, the part time indicator
lights when the transfer case is engaged in the 4H or
4L positions. On vehicles equipped with the optional
Selec-Trac four-wheel drive system, the part time
KJINSTRUMENT CLUSTER 8J - 29
SECURITY INDICATOR (Continued)

indicator lights when the transfer case is engaged in
the4X4Part Time position. This indicator is con-
trolled by a transistor on the instrument cluster elec-
tronic circuit board based upon the cluster
programming and electronic messages received by
the cluster from the Powertrain Control Module
(PCM) over the Programmable Communications
Interface (PCI) data bus. The instrument cluster
must be configured for the type of transfer case in
the vehicle using a DRBIIItscan tool in order to pro-
vide proper operation of the part time indicator. The
part time 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 receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the LED will
always be off when the ignition switch is in any posi-
tion except On or Start. 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 part time indicator for the following rea-
sons:
²Part Time Lamp-On Message- Each time the
cluster receives a part time lamp-on message from
the PCM indicating that a four-wheel drive part time
position of the transfer case has been selected, the
part time indicator will be illuminated. The indicator
remains illuminated until the cluster receives a part
time lamp-off message from the PCM or until the
ignition switch is turned to the Off position, which-
ever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the part time indicator will
be turned on, then off again during the bulb check
portion of the test to confirm the functionality of the
LED and the cluster control circuitry.
The PCM continually monitors the transfer case
switch to determine the driveline operating mode.
The PCM then sends the proper part time lamp-on
and lamp-off messages to the instrument cluster. For
further diagnosis of the part time indicator or the
instrument cluster circuitry that controls the indica-
tor, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). For
proper diagnosis of the transfer case switch, the
PCM, the PCI data bus, or the electronic message
inputs to the instrument cluster that control the part
time indicator, a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
OPERATION - FULL TIME INDICATOR
The full time indicator gives an indication to the
vehicle operator that a four-wheel drive full time
operating mode of the transfer case is selected. On
vehicles equipped with the optional Selec-Trac four-wheel drive system, the full time indicator lights
when the transfer case is engaged in the4X4Full
Time position. This indicator is controlled by a tran-
sistor on the instrument cluster electronic circuit
board based upon the cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus. The
instrument cluster must be configured for the type of
transfer case in the vehicle using a DRBIIItscan
tool in order to provide proper operation of the full
time indicator. The full time 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 receives a battery current input on the fused
ignition switch output (run-start) circuit. Therefore,
the LED will always be off when the ignition switch
is in any position except On or Start. The LED only
illuminates when it is provided a path to ground by
the instrument cluster transistor. The instrument
cluster will turn on the full time indicator for the fol-
lowing reasons:
²Full Time Lamp-On Message- Each time the
cluster receives a full time lamp-on message from the
PCM indicating that a four-wheel drive full time
position of the transfer case has been selected, the
full time indicator will be illuminated. The indicator
remains illuminated until the cluster receives a full
time lamp-off message from the PCM or until the
ignition switch is turned to the Off position, which-
ever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the full time indicator will
be turned on, then off again during the bulb check
portion of the test to confirm the functionality of the
LED and the cluster control circuitry.
The PCM continually monitors the transfer case
switch to determine the driveline operating mode.
The PCM then sends the proper full time lamp-on
and lamp-off messages to the instrument cluster. For
further diagnosis of the full time indicator or the
instrument cluster circuitry that controls the indica-
tor, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). For
proper diagnosis of the transfer case switch, the
PCM, the PCI data bus, or the electronic message
inputs to the instrument cluster that control the full
time indicator, a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
OPERATION - FOUR LOW MODE INDICATOR
The four low mode indicator gives an indication to
the vehicle operator that a four-wheel drive low oper-
ating mode of the transfer case is selected. On vehi-
cles equipped with the standard Command-Trac four-
8J - 30 INSTRUMENT CLUSTERKJ
SHIFT INDICATOR (TRANSFER CASE) (Continued)

wheel drive system, the four low mode indicator
lights when the transfer case is engaged in the 4L
position. On vehicles equipped with the optional
Selec-Trac four-wheel drive system, the four low
mode indicator lights when the transfer case is
engaged in the 4 Lo position. This indicator is con-
trolled by a transistor on the instrument cluster elec-
tronic circuit board based upon the cluster
programming and electronic messages received by
the cluster from the Powertrain Control Module
(PCM) over the Programmable Communications
Interface (PCI) data bus. The instrument cluster
must be configured for the type of transfer case in
the vehicle using a DRBIIItscan tool in order to pro-
vide proper operation of the four low mode indicator.
The four low mode 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
receives a battery current input on the fused ignition
switch output (run-start) circuit. Therefore, the LED
will always be off when the ignition switch is in any
position except On or Start. The LED only illumi-
nates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster
will turn on the four low mode indicator for the fol-
lowing reasons:
²Four Low Mode Lamp-On Message- Each
time the cluster receives a four low mode lamp-on
message from the PCM indicating that a four-wheel
drive low position of the transfer case has been
selected, the four low mode indicator will be illumi-
nated. The indicator remains illuminated until the
cluster receives a four low mode lamp-off message
from the PCM or until the ignition switch is turned
to the Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the four low mode indica-
tor will be turned on, then off again during the bulb
check portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
The PCM continually monitors the transfer case
switch to determine the driveline operating mode.
The PCM then sends the proper four low mode
lamp-on and lamp-off messages to the instrument
cluster. For further diagnosis of the four low mode
indicator or the instrument cluster circuitry that con-
trols the indicator, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND
TESTING). For proper diagnosis of the transfer case
switch, the PCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the four low mode indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.SKIS INDICATOR
DESCRIPTION
A Sentry Key Immobilizer System (SKIS) indicator
is standard equipment on all instrument clusters, but
is only operational on vehicles equipped with the
optional SKIS. The SKIS indicator is located above
the fuel gauge and to the left of the tachometer in
the instrument cluster. The SKIS indicator consists
of a stencil-like cutout of a graphical representation
or icon of a key that is circled and crossed-out 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
indicator to appear in amber through the translucent
outer layer of the overlay when it is illuminated from
behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The SKIS
indicator is serviced as a unit with the instrument
cluster.
OPERATION
The Sentry Key Immobilizer System (SKIS) indica-
tor gives an indication to the vehicle operator of the
status of the SKIS. This indicator is controlled by a
transistor on the instrument cluster electronic circuit
board based upon the cluster programming and elec-
tronic messages received by the cluster from the Sen-
try Key Immobilizer Module (SKIM) over the
Programmable Communications Interface (PCI) data
bus. The SKIS indicator Light Emitting Diode (LED)
is completely controlled by the instrument cluster
logic circuit, and that logic will only allow this indi-
cator to operate when the instrument cluster receives
a battery current input on the fused ignition switch
output (run-start) circuit. Therefore, the LED will
always be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is switched to ground by the instrument clus-
ter transistor. The instrument cluster will turn on
the SKIS indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position, the SKIM tells the cluster
to illuminate the SKIS indicator for about three sec-
onds as a bulb test.
²SKIS Lamp-On Message- Each time the clus-
ter receives a SKIS lamp-on message from the SKIM,
the SKIS indicator will be illuminated. The indicator
can be flashed on and off, or illuminated solid, as dic-
tated by the SKIM message. For more information on
the SKIS and the SKIS indicator control parameters,
(Refer to 8 - ELECTRICAL/VEHICLE THEFT SECU-
RITY - OPERATION). The indicator remains illumi-
nated until the cluster receives a SKIS lamp-off
KJINSTRUMENT CLUSTER 8J - 31
SHIFT INDICATOR (TRANSFER CASE) (Continued)

INSTALLATION
CAUTION: Always use the correct bulb size and
type for replacement. An incorrect bulb size or type
may overheat and cause damage to the lamp, the
socket and/or the lamp wiring.
(1) Align the base of the bulb with the receptacle
in the Center High Mounted Stop Lamp (CHMSL)
unit socket.
(2) Push the bulb straight into the CHMSL unit
socket until it is firmly seated.
(3) Align the socket and bulb with the socket open-
ing on the back of CHMSL unit housing.
(4) Push the socket and bulb straight into the
CHMSL unit housing until it is firmly seated (Fig. 6).
(5) Rotate the socket on the back of the CHMSL
unit housing clockwise about 30 degrees.
(6) Reinstall the CHMSL unit onto the roof panel.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/CENTER HIGH MOUNTED STOP
LAMP UNIT - INSTALLATION).
(7) Reconnect the battery negative cable.
CENTER HIGH MOUNTED
STOP LAMP UNIT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the two screws that secure the Center
High Mounted Stop Lamp (CHMSL) unit to the rear
of the roof panel (Fig. 7).
(3) Pull the CHMSL unit away from the roof panel
far enough to access and disconnect the wire harness
connector for the CHMSL unit from the lamp socket
pigtail wire.
(4) Remove the CHMSL unit from the roof panel.
INSTALLATION
(1) Position the Center High Mounted Stop Lamp
(CHMSL) unit to the roof panel.
(2) Reconnect the wire harness connector for the
CHMSL unit to the lamp socket pigtail wire (Fig. 7).
(3) Position the CHMSL unit into the roof panel
opening.
(4) Install and tighten the two screws that secure
the CHMSL unit to the rear of the roof panel.
Tighten the screws to 2 N´m (21 in. lbs.).
(5) Reconnect the battery negative cable.
COMBINATION FLASHER
DESCRIPTION
The combination flasher for this model is integral
to the hazard switch located in the center of the
instrument panel, just above the radio. The combina-
tion flasher is a smart relay that functions as both
the turn signal system and the hazard warning sys-
tem flasher. The combination flasher contains active
electronic Integrated Circuitry (IC) elements. This
flasher is designed to handle the current flow
requirements of the factory-installed lighting. If sup-
plemental lighting is added to the turn signal lamp
circuits, such as when towing a trailer with lights,
the combination flasher will automatically try to
compensate to keep the flash rate the same.
The combination flasher cannot be repaired or
adjusted and, if faulty or damaged, the hazard switch
unit must be replaced.
OPERATION
The combination flasher has the following inputs and
outputs: fused B(+), fused ignition switch output, right
turn signal sense, left turn signal sense, and one output
each for the right and left turn signal circuits. The com-
bination flasher also receives an internal input through
the closed contacts of the hazard switch and, on vehicles
equipped with the optional Vehicle Theft Security Sys-
tem (VTSS), the flasher receives an input from the Body
Control Module (BCM) in order to flash the turn signal
lamps as an optical alert feature of that system. Con-
Fig. 7 Center High Mounted Stop Lamp Remove/
Install
1 - ROOF PANEL
2 - BODY WIRE HARNESS CONNECTOR
3 - BULB SOCKET
4 - CHMSL
5 - SCREW (2)
6 - PLASTIC NUT (2)
KJLAMPS/LIGHTING - EXTERIOR 8L - 19
CENTER HIGH MOUNTED STOP LAMP BULB (Continued)

path to the switches using another internal driver
through the courtesy lamp load shed circuit. The
BCM provides a battery saver (load shedding) feature
for all courtesy lamps, which will automatically turn
these lamps off if they are left on for more than
about eight minutes with the ignition switch in the
Off position.
PANEL LAMPS DIMMER CIRCUIT The panel
lamps dimmer circuit includes the ElectroMechanical
Instrument Cluster (EMIC), heater-air conditioner
control, hazard switch and, depending upon the
selected vehicle options, ash receiver, and automatic
transmission range indicator illumination lamps. All
lamps in the panel lamps dimmer circuit are pro-
vided a path to ground at all times through a hard
wired ground circuit. These lamps illuminate based
upon inputs to the Body Control Module (BCM) from
the exterior lighting control knob and the interior
lighting control ring on the left (lighting) control
stalk of the multi-function switch. The control knob
on the left control stalk of the multi-function switch
selects the exterior lights, while the control ring
selects the panel lamps intensity (dimming) level.
When the exterior lighting is turned On, the BCM
energizes the park lamp relay and provides an elec-
tronic dimming level message to the ElectroMechani-
cal Instrument Cluster (EMIC), the radio, and the
Compass Mini-Trip Computer (CMTC) over the Pro-
grammable Communications Interface (PCI) data
bus. The energized park lamp relay provides a hard
wired battery current signal input to the EMIC on
the park lamp relay output circuit. The EMIC
responds to these inputs by supplying a 12-volt Pulse
Width Modulated (PWM) output to all of the incan-
descent lamps in the panel lamps dimmer circuit
over the fused panel lamps dimmer switch signal cir-
cuit. This shared PWM output synchronizes the
selected illumination intensity level of all of the
incandescent lamps in the panel lamps dimmer cir-
cuit.
The EMIC and the radio each use the electronic
dimming level message from the BCM to control and
synchronize the illumination intensity of their own
Vacuum Fluorescent Display (VFD), while the CMTC
uses the dimming level message to control the illumi-
nation intensity of both its VFD and its incandescent
lighting. In addition, when the control ring on the
left (lighting) control stalk of the multi-function
switch is moved to the Parade Mode detent position,
all of the VFDs are illuminated at their full intensity
levels for increased visibility when the vehicle is
driven during daylight hours with the exterior lights
turned On.DIAGNOSIS AND TESTING - LAMPS/LIGHTING
- INTERIOR
The hard wired circuits and components of the
interior lighting system may be diagnosed and tested
using conventional diagnostic tools and procedures.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the Body Control
Module (BCM), the ElectroMechanical Instrument
Cluster (EMIC), or the Programmable Communica-
tions Interface (PCI) data bus network. The most
reliable, efficient, and accurate means to diagnose
the BCM, the EMIC, and the PCI data bus network
inputs and outputs related to the various interior
lighting systems requires the use of a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
When diagnosing the interior lighting circuits,
remember that high generator output can burn out
bulbs rapidly and repeatedly; and, that dim or flick-
ering bulbs can be caused by low generator output or
poor battery condition. If one of these symptoms is a
problem on the vehicle being diagnosed, be certain to
diagnose and repair the battery and charging system
as required. Also keep in mind that a good ground is
necessary for proper lighting operation. If a lighting
problem is being diagnosed that involves multiple
symptoms, systems, or components the problem can
often be traced to a loose, corroded, or open ground.
For complete circuit diagrams, refer to the appropri-
ate wiring information. The wiring 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 connec-
tors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
8L - 68 LAMPS/LIGHTING - INTERIORKJ
LAMPS/LIGHTING - INTERIOR (Continued)