Page 545 of 1938

instrument cluster for 6 seconds after the instrument
cluster receives the message from the Body Control
Module. The seat belt lamp is therefore illuminated
for 6 seconds whenever the ignition switch is moved
to run/start position.
(1) While ignition is off, the seat belt lamp will not
be illuminated.
(2) The ignition power feed status will be updated
every 250 milliseconds or on change.
(3) This lamp will be checked by the instrument
cluster for 6 seconds with every run/start cycle of the
ignition switch.
TURN SIGNAL ON CHIME
The turn signal on chime will warn the driver that
the turn signals have been left on. When the body
control module receives a turn signal input for 6.4
km (4.0 miles), vehicle speed is greater than 24 km/h
(15 mph), the chime will sound continuously until the
turn signal is turned OFF. If vehicle speed drops
below 24 km/h (15 mph) prior to the warning being
activated, the accumulated distance traveled will be
reset. The turn signal chime is not activated when
the emergency flashers are turned on. This feature
can also be disabled in EEPROM. Chime rate: 50
chimes per minute.
For the turn signal warning system to operate:
²Must have input from either the right or left
turn signal lamps. Creates a voltage change between
0 and battery voltage.
²The vehicle speed sensor sends a message to the
Powertrain Control Module that vehicle has exceeded
24 km/h (15 mph) for 6.4 km (4.0 miles).
²When the above two conditions are met, the
chime will sound. The chime will stop when no fur-
ther voltage change is detected.²If hazard warning signals are pulsing, no chime
will sound.
²If speed drops below 24 km/h (15 mph) before
the warning is issued, the warning will not be issued
and the distance counter will be reset.
²If turn signal lamps are not working properly,
the chime will not sound.
²When using the scan tool, refer to the proper
Body Diagnostic Manual for the procedure.
WARNING LAMP ANNOUNCEMENT CHIME
The warning lamp announcement chime will warn
the driver to scan the instrument cluster to observe
which warning lamp is illuminated. Whenever the
volts, low fuel, low washer/coolant level, door ajar or
gate ajar lamps are first illuminated, the chime will
sound one tone. The door/liftgate ajar warning lamp
announcement chime sounds only if the vehicle speed
is above 2 m.p.h.
Two seconds after ignition switch is turned ON or
until the seat belt warning chime ends, all warning
announcement chimes will be consolidated into one
warning announcement. This will occur 2 seconds
after the seat belt warning chime ends. If a warning
announcement should occur while another warning
chime in progress (turn signal, low oil pressure or
high speed warnings), no additional chimes will
sound after the chime in progress ends. All associ-
ated lamps will be illuminated, and the active chime
will be the warning announcement.
NSCHIME WARNING/REMINDER SYSTEM 8U - 3
DIAGNOSIS AND TESTING (Continued)
Page 546 of 1938
Page 547 of 1938

CHIME WARNING/REMINDER SYSTEM
CONTENTS
page page
GENERAL INFORMATION
INTRODUCTION........................ 1
DIAGNOSIS AND TESTING
CATALYST OVERHEAT WARNING CHIME.... 1
CHIME SYSTEM DIAGNOSIS.............. 1
DOME LAMP ON CHIME................. 2
ENGINE TEMPERATURE CRITICAL CHIME . . . 2EXTERIOR LAMPS ON CHIME............. 2
KEY-IN IGNITION CHIME................. 2
LOW OIL PRESSURE CHIME OPERATION . . . 2
SEAT BELT CHIME...................... 3
SEAT BELT LAMP...................... 3
TURN SIGNAL ON CHIME................ 3
WARNING LAMP ANNOUNCEMENT CHIME . . 3
GENERAL INFORMATION
INTRODUCTION
WARNING: ON VEHICLES EQUIPPED WITH AN
AIRBAG, REFER TO GROUP 8M, RESTRAINT SYS-
TEMS FOR SAFETY PRECAUTIONS AND WARN-
INGS TO OBSERVE WHEN SERVICING AIRBAG
RELATED COMPONENTS.
The chime system provides the driver with warn-
ing chimes for:
²Seat Belt
²Exterior Lamps ON
²Key-In Ignition
²Engine Temperature Critical
²Turn Signals ON
²Dome Lamp ON
²Low Oil Pressure
²High Speed Warning
²Warning Lamp Announcement
²Catalyst Overheating
The Chime Warning/Reminder System is diagnosed
using a scan tool (DRB). Refer to the proper Body
Diagnostic Procedures manual for testing procedures
and scan tool usage instructions.
DIAGNOSIS AND TESTING
CATALYST OVERHEAT WARNING CHIME
The Catalyst Overheat Warning Chime will act as
a warning to the driver that the vehicle's catalyst
has entered an overheat condition. The Powertrain
Control Module (PCM) will enable or disable this fea-
ture for the appropriate vehicles. Right hand drive
gas vehicles only. The Body Control Module (BCM)
will monitor the CCD bus for status and signal a cat-
alyst overheat condition with continuous warning
chime when the following conditions are met:²Ignition switch in the ON position
²Engine running at 420 to 480 rpm for 10 sec-
onds
²CCD status and with a chime rate of one chime
per second.
CHIME SYSTEM DIAGNOSIS
NO TONE WHEN IGNITION SWITCH IS
TURNED ON AND DRIVER'S SEAT BELT IS
NOT BUCKLED.
(1) Using a scan tool (DRB), check for tone in any
other function.
(2) Using a voltmeter, check for voltage:
(a) Pin 9 of the internal 32 way connector of the
BCM for battery feed.
(b) Pin 8 of the internal 32 way connector of the
BCM for ignition feed.
(c) If voltage OK, go to step Step 3
(d) If NO voltage repair as necessary. Refer to
Group 8W, Wiring Diagrams for component loca-
tions and circuit information.
(3) Check driver's seat belt buckle switch input for
a closed circuit when not buckled. If input not seen,
look for open in wiring or switch. The switch is
grounded when belt is not buckled.
(4) Repair as necessary.
NO FASTEN SEAT BELT LAMP WHEN
IGNITION SWITCH IS TURNED ON.
(1) Check for burned out lamp.
(2) Using a voltmeter check for voltage:
(a) Pin 2 of the mechanical instrument cluster
for battery feed.
(b) Pin 11 of the mechanical instrument cluster
for ignition voltage.
(3) Repair as necessary.
NS/GSCHIME WARNING/REMINDER SYSTEM 8U - 1
Page 548 of 1938

FASTEN SEAT BELT LAMP OR TONE
CONTINUES FOR MORE THAN 10 SECONDS
AFTER SEAT BELTS ARE FASTENED AND
DRIVER'S DOOR IS CLOSED.
(1) Check left door ajar switch for no ground when
switch is depressed.
(a) If continuity replace door ajar switch.
(b) If NO continuity replace BCM for tone condi-
tion, or replace mechanical instrument panel for
lamp condition.
(c) Replace BCM for tone condition.
(d) Replace mechanical instrument cluster for
lamp condition.
NO TONE WHEN PARK OR HEADLAMPS ARE
ON AND DRIVER'S DOOR IS OPEN.
(1) Check left door ajar switch for good ground
when driver's door is open. Repair as necessary.
(2) Inspect BCM connectors and wires for proper
connection. If OK, replace BCM for tone condition.
DOME LAMP ON CHIME
The dome lamp on chime will warn the driver that
the dome lamps have been left on.
With the ignition is OFF:
²Driver's door OPEN (door ajar switch is closed to
ground)
²Dome lamps are ON (dome lamp switch is closed
to ground),
The chime will sound continuously until driver's
door is closed, dome lamps tuned OFF or until the
battery protection time out of 15 minutes has
expired. Refer Group 8L, Lamps proper procedures.
Chime rate: 168 to 192 chimes per minute.
ENGINE TEMPERATURE CRITICAL CHIME
The engine temperature critical chime will warn
the driver that the vehicle's engine is overheating.
While monitoring the coolant temperature, the Pow-
ertrain Control Module (PCM) will send on the CCD
bus as engine temperature every 1.376 seconds to the
Body Control Module (BCM). The BCM calculates
engine temperature and determines if a warning
should occur. This feature is functional only with the
Ignition Switch in the Run/Start position. On the
Diesel vehicles, the coolant temperature sensor is
read directly by the BCM.
When the engine temperature reaches 122ÉC
(252ÉF) or the diesel engine 112ÉC (234ÉF), the BCM
will chime one tone and the engine temperature lamp
comes ON. The BCM turns OFF the lamp when the
engine temperature reaches 117ÉC (242ÉF) or the die-
sel engine 108ÉC (226ÉF). The BCM will chime con-
tinuously when the engine temperature reaches
125ÉC (257ÉF) or diesel engine 116ÉC (241ÉF). The
chime will turn OFF after four minutes or when thetemperature reaches 117ÉC (242ÉF) or diesel engine
108ÉC (226ÉF), which ever occurs first.
EXTERIOR LAMPS ON CHIME
The exterior lamp on chime will warn the driver
that the exterior lights have been left on.
With the ignition switch OFF:
²Driver's door is open (door ajar switch is closed
to ground)
²Parking lamps or headlamps ON (parking lamp
switch is closed to ground)
The chime will sound until lights are turned OFF,
driver's door closed or until the battery protection
time out of 3 minutes has expired.
Refer to Group 8L, Lamps, for proper service pro-
cedures. Chime rate: 168 to 192 chimes per minute.
To test the exterior lamps left on function:
²Turn ignition off
²Remove ignition key
²Turn exterior lamps on with driver's door open.
Chime should sound until lamps are turned off or
driver's door is closed.
KEY-IN IGNITION CHIME
The key-in ignition chime will act as a warning to
the driver that the ignition key has been left in the
ignition switch.
With the ignition switch is in OFF position ONLY:
²Driver's door is open/ajar (door ajar switch is
closed to ground)
²Key is in the ignition switch (key-in ignition
switch is closed to ground)
The chime will sound until one of the above condi-
tions is removed. Chime rate: 168 to 192 chimes per
minute.
To test the key-in ignition function, insert key into
the ignition and open driver's door. Do not turn igni-
tion ON. Chime should sound until key is removed
from ignition or driver's door is closed.
LOW OIL PRESSURE CHIME OPERATION
The low oil pressure chime will warn the driver
that the engine oil pressure is low. The oil pressure
switch, will close to ground during a low oil pressure
condition. The oil pressure lamp will illuminate in
the message center. The body control module will
monitor the oil pressure switch and signal a low oil
pressure condition. A continuous four minute warn-
ing chime will sound and the oil pressure lamp will
come ON when the following conditions are met:
²Ignition on and engine not cranking
²Engine running at 420 to 480 rpm for 10 sec-
onds
²Oil pressure switch closed to ground for (1 sec-
ond minimum, 2 seconds maximum)
Chime rate: 168 to 192 chimes per minute.
8U - 2 CHIME WARNING/REMINDER SYSTEMNS/GS
DIAGNOSIS AND TESTING (Continued)
Page 549 of 1938

SEAT BELT CHIME
The seat belt chime will sound for 4 to 8 seconds,
when the ignition is turned on and the driver's seat
belt is not buckled (seat belt switch is closed to
ground). This is a reminder to the driver to buckle
the seat belt. The seat belt lamp is controlled by the
mechanical instrument cluster. The cluster will also
illuminate the seat belt warning lamp for 6 seconds.
Buckling the driver's seat belt before the time out
has expired will cause the chime to stop immediately.
Chime rate: 38 to 62 chimes per minute.
To test the seat belt warning system, the ignition
switch must be in the OFF position for 1 minute
before starting the test. Turn the ignition switch to
the on position with the driver's seat belt not buck-
led. The seat belt warning lamp should light and the
chime should sound 4 to 8 seconds.
SEAT BELT LAMP
The seat belt lamp in the instrument cluster sig-
nals the vehicle passengers to fasten their seat belts.
The seat belt lamp is illuminated directly by the
instrument cluster for 6 seconds after the instrument
cluster receives the message from the Body Control
Module. The seat belt lamp is therefore illuminated
for 6 seconds whenever the ignition switch is moved
to run/start position.
(1) While ignition is off, the seat belt lamp will not
be illuminated.
(2) The ignition power feed status will be updated
every 250 milliseconds or on change.
(3) This lamp will be checked by the instrument
cluster for 6 seconds with every run/start cycle of the
ignition switch.
TURN SIGNAL ON CHIME
The turn signal on chime will warn the driver that
the turn signals have been left on. When the Body
Control Module receives a turn signal input for 1.6
km (1.0 miles), vehicle speed is greater than 24 km/h
(15 mph), the chime will sound continuously until the
turn signal is turned OFF. If vehicle speed drops
below 24 km/h (15 mph) prior to the warning being
activated, the accumulated distance traveled will be
reset. The turn signal chime is not activated whenthe emergency flashers are turned on. This feature
can also be disabled in EEPROM. Chime rate: 38 to
62 chimes per minute.
For the turn signal warning system to operate:
²Must have input from either the right or left
turn signal lamps. Creates a voltage change between
0 and battery voltage.
²The vehicle speed sensor sends a message to the
Powertrain Control Module that vehicle has exceeded
24 km/h (15 mph) for 1.6 km (1.0 miles).
²When the above two conditions are met, the
chime will sound. The chime will stop when no fur-
ther voltage change is detected.
²If hazard warning signals are pulsing, no chime
will sound.
²If speed drops below 24 km/h (15 mph) before
the warning is issued, the warning will not be issued
and the distance counter will be reset.
²If turn signal lamps are not working properly,
the chime will not sound.
²When using the scan tool, refer to the proper
Body Diagnostic Manual for the procedure.
WARNING LAMP ANNOUNCEMENT CHIME
The warning lamp announcement chime will warn
the driver to scan the instrument cluster to observe
which warning lamp is illuminated. Whenever the
volts, low fuel, low washer fluid, coolant level (gas/
diesel), low coolant level, engine temperature high
(diesel only), door ajar or gate ajar lamps are first
illuminated, the chime will sound one tone. The door/
liftgate ajar warning lamp announcement chime
sounds only if the vehicle speed is above 2 m.p.h.
Two seconds after ignition switch is turned ON or
until the seat belt warning chime ends, all warning
announcement chimes will be consolidated into one
warning announcement. This will occur 2 seconds
after the seat belt warning chime ends. If a warning
announcement should occur while another warning
chime in progress (turn signal, low oil pressure or
high speed warnings), no additional chimes will
sound after the chime in progress ends. All associ-
ated lamps will be illuminated, and the active chime
will be the warning announcement.
NS/GSCHIME WARNING/REMINDER SYSTEM 8U - 3
DIAGNOSIS AND TESTING (Continued)
Page 550 of 1938
Page 551 of 1938

OVERHEAD CONSOLE
CONTENTS
page page
DESCRIPTION AND OPERATION
COMPASS MINI-TRIP COMPUTER (CMTC).... 1
COMPASS/TEMPERATURE MINI TRIP
COMPUTER SELF-DIAGNOSTIC TEST....... 1
THERMOMETER AND COMPASS............ 2
UNIVERSAL TRANSMITTER................ 2
DIAGNOSIS AND TESTING
READING/DOME LAMP DIAGNOSIS......... 3
TRAVELER MESSAGES.................... 3
UNIVERSAL TRANSMITTER................ 3
SERVICE PROCEDURES
COMPASS CALIBRATION PROCEDURE (FAST
METHOD)............................. 4
COMPASS CALIBRATION PROCEDURE....... 4
DEMAGNETIZING PROCEDURE............. 4UNIVERSAL TRANSMITTER................ 5
REMOVAL AND INSTALLATION
AMBIENT TEMPERATURE SENSOR.......... 5
COMPASS MINI-TRIP COMPUTER (CMTC)
LAMP BULBS......................... 6
COMPASS MINI-TRIP COMPUTER (CMTC)
MODULE............................. 6
FRONT HEADER READING/COURTESY LAMP . . 6
OVERHEAD CONSOLE.................... 6
READING/COURTESY LAMP ASSEMBLY...... 7
READING/COURTESY LAMP............... 6
UNIVERSAL TRANSMITTER................ 7
SPECIAL TOOLS
SPECIAL TOOL.......................... 9
DESCRIPTION AND OPERATION
COMPASS/TEMPERATURE MINI TRIP COMPUTER
SELF-DIAGNOSTIC TEST
The CMTC is capable of performing a diagnostic
self check on many of its internal functions. CMTC
diagnostics may be performed using a scan tool
(DRB) and the proper Body Diagnostic Procedures
manual or by the following procedure.
(1) With the ignition switch in the OFF position,
press both the US/M and STEP button.
(2) Turn ignition switch to the ON position.
The CMTC will perform internal checks while
lighting all segments of the vacuum florescent dis-
play. Upon completion of the internal check, the
CMTC will display.
²PASS
²FAIL
²CCd
If any segment of the CMTC fails to light replace
the module.
If FAIL is displayed, replace the module.
If CCd is displayed, check the CCD and Body Con-
trol Module (BCM) for proper operation, refer to the
appropriate diagnostic test procedures manual If the
CCD and the BCM are OK, replace the CMTC mod-
ule.
For additional diagnostic information on the CMTC
and for identifying CMTC problems, refer to the
proper Body Diagnostic Procedures manual.
COMPASS MINI-TRIP COMPUTER (CMTC)
The Compass Mini-Trip Computer (CMTC) system
is located in the overhead console. CMTC consists of
a electronic control module with a vacuum fluores-
cent display (VFD) and function switches. The CMTC
consists of a electronic module that displays compass,
trip computer, and temperature features. Actuating
the STEP switch will cause the CMTC to change
mode of operation when ignition is ON. Example:
²Compass/Temperature
²Trip odometer (ODO)
²Average miles per gallon (ECO)
²Instant miles per gallon (ECO)
²Distance to empty (DTE)
²Elapsed time (ET)
²Off
The CMTC module in the overhead console has
three buttons used to select various functions. The
CMTC selector buttons will not operate until the
ignition is in the RUN position (Fig. 1).
When the ignition switch is first turned to the
RUN position the CMTC display;
²Blanks momentarily
²All segments of the VFD will light for one sec-
ond
²Blanks momentarily
²Returns to the last mode setting selected before
the ignition was last switched OFF.
NSOVERHEAD CONSOLE 8V - 1
Page 552 of 1938

THERMOMETER AND COMPASS
THERMOMETER
Engine temperature can increase the displayed
temperature. The CMTC is designed to dampen tem-
perature readings when the vehicle is moving at a
rate slower than 18 miles per hour.
The outside temperature is measured from a sen-
sor mounted in the front of the vehicle. If the tem-
perature is more than 55ÉC (131ÉF) or the
temperature sending line is shorted to ground, the
temperature display should read SC. If the tempera-
ture is less than -40ÉC (-40ÉF), or the sending line is
an open circuit, the display should read OC.
The CMTC will not allow the temperature reading
to increase when the vehicle is not moving.
COMPASS
The CMTC is self calibrating and usually requires
no adjustment. The compass will continuously per-
form a slow calibration to compensate for small mag-
netic variations common to any automobile.
Uncommon magnetic shifts may be caused by items
such as magnetic base antennas, which can perma-
nently alter the magnetic field of the vehicle roof
panel. If excessive magnetic field continues for 5 min-
utes, the compass heading will go blank and only the
CAL symbol will illuminate. When this occurs, the
vehicle roof panel may require demagnetizing. Refer
to the demagnetizing procedure in this section.
Moderate magnetic shifts may, on very rare occa-
sions, cause the compass heading to display only one
or two of the eight possible headings. Although the
compass will eventually compensate for this shift, it
could take several ignition cycles. The compensation
process can be expedited by manually activating the
fast calibration routine. Refer to the fast calibrating
procedure in this section. This procedure may be per-formed anytime that the compass appears to be inac-
curate.
If the calibration data stored in the body control
module is not received, the compass will read only
NE North-East. The CMTC is self calibrating and
requires no adjusting. The word CAL is displayed to
show that the compass is in calibration mode. CAL
will turn off after the vehicle has gone through three
complete circles without stopping, in an area free of
magnetic disturbance. If module displays tempera-
ture while the compass is blank, turn off ignition and
run self diagnostics then demagnetize the vehicle.
After demagnetizing, check compass calibration num-
ber, refer to Self Diagnostic Test. If greater than 15,
demagnetize again until reading is less than 15. If
compass still goes blank after demagnetizing then
check internal diagnostics and demagnetize.
UNIVERSAL TRANSMITTER
The Universal Transmitter, replaces the hand held
remote controls that open the garage door, motorized
gates, or home lighting in/outside the home. This
device memorizes the activator codes for up to three
remote controlled devices. It triggers those devices at
the push of a button, located in a unit permanently
mounted in your overhead console (if equipped).
The transmitter operates off your vehicle's battery
and charging system; no batteries are needed.
The Universal Transmitter incorporates a Rolling
Code technology (random digital code signals from
the remote transmitter) within the transmitter mod-
ule. This is done so, as an added security measure.
Features of the Universal Transmitter are:
²Can be used with most other Radio Frequency
(RF) activated devices.
²Individual channels can be trained.
Fig. 1 Compass Mini-Trip Computer (CMTC)
Switches and Display
Fig. 2 Universal Transmitter Location
8V - 2 OVERHEAD CONSOLENS
DESCRIPTION AND OPERATION (Continued)