1998 DODGE RAM 1500 service reset

The optional navigation radio system receives GPS
signals from up to eight satellites to display the posi-
tion and direction of the vehicle. Map information is
supplied through a DVD-ROM. An electronic gyro-
sensor and the vehicle's speed sensor enable the sys-
tem to display the present vehicle position even in
locations where GPS signals may be blocked.
When a destination is selected, the navigation sys-
tem uses information from the map to quickly calcu-
late a route. As the vehicle is driven along the chosen
route, the operator is guided with pictorial displays
and voice prompts. For complete operating instruc-
tions, refer to the manual included with the vehicle.
On vehicles that are equipped with the optional
remote radio switches, the Instrument Cluster
receives hard wired resistor multiplexed inputs from
the remote radio switches. The programming in the
Instrument Cluster allows it to process those inputs
and send the proper messages to the radio receiver
over the Programmable Communication Interface
(PCI) bus network to control the radio volume up or
down, station seek up or down, preset station
advance, and mode advance functions.DIAGNOSIS AND TESTING - AUDIO
Any diagnosis of the Audio system should
begin with the use of the DRB IIItdiagnostic
tool. For information on the use of the
DRB IIIt, refer to the appropriate Diagnostic
Service Manual.
Refer to the appropriate wiring information.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, 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 ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
AUDIO SYSTEM DIAGNOSIS TABLE
CONDITION POSSIBLE CAUSES CORRECTION
NO AUDIO 1. Fuse faulty. 1. Check radio fuse and Ignition-Off Draw (IOD)
fuse in the Integrated Power Module (IPM).
Replace fuses, if required.
2. Radio/amplifier (if
equipped) connector faulty.2. Check for loose or corroded radio/amplifier
connector. Repair, if required.
3. Wiring faulty. 3. Check for shorted or open wires. Repair wiring,
if required.
4. Radio/amplifier (if
equipped) ground faulty.4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
5. Radio/amplifier (if
equipped) faulty.5. Refer to appropriate Diagnostic Service
Manual.
6. Speakers faulty. 6. Replace speaker as necessary.
NO RADIO DISPLAY 1. Fuse faulty. 1. Check radio fuse and Ignition-Off Draw (IOD)
fuse in Integrated Power Module (IPM). Replace
fuses, if required.
2. Radio connector faulty. 2. Check for loose or corroded radio connector.
Repair, if required.
3. Wiring faulty. 3. Check for battery voltage at radio connector.
Repair wiring, if required.
4. Radio ground faulty. 4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
5. Radio faulty. 5. Refer to appropriate Diagnostic Service
Manual.
8A - 2 AUDIO/VIDEODR
AUDIO (Continued)

OPERATION
The six switches in the two remote radio switch
units are normally open, resistor multiplexed
momentary switches that are hard wired to the Inte-
grated Power Module (IPM) through the clockspring.
The IPM sends a five volt reference signal to both
switch units on one circuit, and senses the status of
all of the switches by reading the voltage drop on a
second circuit.
When the IPM senses an input (voltage drop) from
any one of the remote radio switches, it sends the
proper switch status messages on the Programmable
Communication Interface (PCI) data bus network to
the radio receiver. The electronic circuitry within the
radio receiver is programmed to respond to these
remote radio switch status messages by adjusting the
radio settings as requested. For diagnosis of the IPM
or the PCI data bus, the use of a DRB IIItscan tool
and the proper Diagnostic Procedures manual are
recommended.
DIAGNOSIS AND TESTING - REMOTE
SWITCHES
Any diagnosis of the Audio system should
begin with the use of the DRB IIItdiagnostic
tool. For information on the use of the
DRB IIIt, refer to the appropriate Diagnostic
Service Manual.
For complete circuit diagrams, refer to the appro-
priate wiring information.WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, 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 ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable. Remove the remote radio switch(es) (Fig. 15)
from the steering wheel (Refer to 8 - ELECTRICAL/
AUDIO/REMOTE SWITCHES - REMOVAL).
(2) Use an ohmmeter to check the switch resis-
tances as shown in the Remote Radio Switch Test
chart. If the remote radio switch resistances check
OK, go to Step 3. If not OK, replace the faulty
switch.
Fig. 14 Remote Radio Switch Operational View
1 - PRESET SEEK
2 - SEEK UP
3 - VOLUME UP
4 - MODE
5 - VOLUME DOWN
6 - SEEK DOWN
Fig. 15 Remote Radio Switches
1 - BLACK (LEFT) SWITCH
2 - WHITE (RIGHT) SWITCH
DRAUDIO/VIDEO 8A - 11
REMOTE SWITCHES (Continued)

sage-controlled functions of the cluster by lighting
the appropriate indicators, positioning the gauge nee-
dles at several predetermined calibration points
across the gauge faces, and illuminating all segments
of the odometer/trip odometer and gear selector indi-
cator Vacuum-Fluorescent Display (VFD) units.
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). See the owner's
manual in the vehicle glove box for more information
on the features, use and operation of the EMIC.
GAUGES
All gauges receive battery current through the
EMIC circuitry only when the ignition switch is in
the On or Start positions. With the ignition switch in
the Off position battery current is not supplied to
any gauges, and the EMIC circuitry is programmed
to move all of the gauge needles back to the low end
of their respective scales. Therefore, the gauges do
not accurately indicate any vehicle condition unless
the ignition switch is in the On or Start positions.
All of the EMIC gauges are air core magnetic
units. Two fixed electromagnetic coils are located
within each gauge. These coils are wrapped at right
angles to each other around a movable permanent
magnet. The movable magnet is suspended within
the coils on one end of a pivot shaft, while the gauge
needle is attached to the other end of the shaft. One
of the coils has a fixed current flowing through it to
maintain a constant magnetic field strength. Current
flow through the second coil changes, which causes
changes in its magnetic field strength. The current
flowing through the second coil is changed by the
EMIC circuitry in response to messages received over
the PCI data bus. The gauge needle moves as the
movable permanent magnet aligns itself to the
changing magnetic fields created around it by the
electromagnets.
The gauges are diagnosed using the EMIC self-di-
agnostic actuator test. (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). Proper testing of the PCI data bus and
the electronic data bus message inputs to the EMIC
that control each gauge require the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation. Specific operation details for each gauge may
be found elsewhere in this service information.
VACUUM-FLUORESCENT DISPLAYS
The Vacuum-Fluorescent Display (VFD) units are
soldered to the EMIC electronic circuit board. With
the ignition switch in the Off or Accessory positions,
the odometer display is activated when the driver
door is opened (Rental Car mode) and is deactivated
when the driver door is closed. Otherwise, both dis-
play units are active when the ignition switch is inthe On or Start positions, and inactive when the igni-
tion switch is in the Off or Accessory positions.
The illumination intensity of the VFD units is con-
trolled by the EMIC circuitry based upon an input
from the headlamp switch and a dimming level input
received from the headlamp dimmer switch. The
EMIC synchronizes the illumination intensity of
other VFD units with that of the units in the EMIC
by sending electronic dimming level messages to
other electronic modules in the vehicle over the PCI
data bus.
The EMIC VFD units have several display capabil-
ities including odometer, trip odometer, engine hours,
gear selector indication (PRNDL) for models with an
automatic transmission, several warning or reminder
indications, and various diagnostic information when
certain fault conditions exist. An odometer/trip odom-
eter switch on the EMIC circuit board is used to con-
trol some of the display modes. This switch is
actuated manually by depressing the odometer/trip
odometer switch button that extends through the
lower edge of the cluster lens, just left of the tachom-
eter. Actuating this switch momentarily with the
ignition switch in the On position will toggle the
VFD between the odometer and trip odometer modes.
Depressing the switch button for about two seconds
while the VFD is in the trip odometer mode will
reset the trip odometer value to zero. While in the
odometer mode with the ignition switch in the On
position and the engine not running, depressing this
switch for about six seconds will display the engine
hours information. Holding this switch depressed
while turning the ignition switch from the Off posi-
tion to the On position will initiate the EMIC self-di-
agnostic actuator test. Refer to the appropriate
diagnostic information for additional details on this
VFD function. The EMIC microprocessor remembers
which display mode is active when the ignition
switch is turned to the Off position, and returns the
VFD display to that mode when the ignition switch is
turned On again.
The VFD units are diagnosed using the EMIC self-
diagnostic actuator test. (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). Proper testing of the PCI data bus and
the electronic data bus message inputs to the EMIC
that control some of the VFD functions requires the
use of a DRBIIItscan tool. Refer to the appropriate
diagnostic information. Specific operation details for
the odometer, the trip odometer, the gear selector
indicator and the various warning and reminder indi-
cator functions of the VFD may be found elsewhere
in this service information.
8J - 8 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

MALFUNCTION INDICATOR
LAMP (MIL)
DESCRIPTION
A Malfunction Indicator Lamp (MIL) is standard
equipment on all instrument clusters (Fig. 22). The
MIL is located on the left side of the instrument clus-
ter, to the left of the voltage gauge. The MIL consists
of a stencil-like cutout of the International Control
and Display Symbol icon for ªEngineº in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents the indicator from
being clearly visible when it is not illuminated. An
amber Light Emitting Diode (LED) behind the cutout
in the opaque layer of the overlay causes the icon to
appear in amber 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 MIL
is serviced as a unit with the instrument cluster.
OPERATION
The Malfunction Indicator Lamp (MIL) gives an
indication to the vehicle operator when the Power-
train Control Module (PCM) on vehicles with a gaso-
line engine, or the Engine Control Module (ECM) on
vehicles with a diesel engine has recorded a Diagnos-
tic Trouble Code (DTC) for an On-Board Diagnostics
II (OBDII) emissions-related circuit or component
malfunction. The MIL is controlled by a transistor on
the instrument cluster circuit board based upon clus-
ter programming and electronic messages received by
the cluster from the PCM or ECM over the Program-
mable Communications Interface (PCI) data bus. The
MIL Light Emitting Diode (LED) is completely con-
trolled by the instrument cluster logic circuit, and
that logic will only allow this indicator to operate
when the instrument cluster receives a battery cur-
rent 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 pro-
vided a path to ground by the instrument cluster
transistor. The instrument cluster will turn on the
MIL for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the indicator is illuminated
for about two seconds as a bulb test. The entire two
second bulb test is a function of the PCM or ECM.²MIL Lamp-On Message- Each time the clus-
ter receives a MIL lamp-on message from the PCM
or ECM, the indicator will be illuminated. The indi-
cator can be flashed on and off, or illuminated solid,
as dictated by the PCM or ECM message. For some
DTC's, if a problem does not recur, the PCM or ECM
will send a lamp-off message automatically. Other
DTC's may require that a fault be repaired and the
PCM or ECM be reset before a lamp-off message will
be sent. For more information on the PCM, the ECM,
and the DTC set and reset parameters, (Refer to 25 -
EMISSIONS CONTROL - OPERATION).
²Communication Error- If the cluster receives
no lamp-on message from the PCM or ECM for ten
seconds, the MIL is illuminated by the instrument
cluster to indicate a loss of bus communication. The
indicator remains controlled and illuminated by the
cluster until a valid lamp-on message is received
from the PCM or ECM.
²Actuator Test- Each time the cluster is put
through the actuator test, the MIL indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
On vehicles with a gasoline engine, the PCM con-
tinually monitors the fuel and emissions system cir-
cuits and sensors to decide whether the system is in
good operating condition. On vehicles with a diesel
engine, the ECM continually monitors the fuel and
emissions system circuits and sensors to decide
whether the system is in good operating condition.
The PCM or ECM then sends the proper lamp-on or
lamp-off messages to the instrument cluster. For fur-
ther diagnosis of the MIL or the instrument cluster
circuitry that controls the LED, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). 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 emis-
sions systems may require service. For proper diag-
nosis of the fuel and emissions systems, the PCM,
the ECM, the PCI data bus, or the electronic mes-
sage inputs to the instrument cluster that control the
MIL, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
Fig. 22 Malfunction Indicator Lamp (MIL)
DRINSTRUMENT CLUSTER 8J - 31

ODOMETER
DESCRIPTION
An odometer and trip odometer are standard
equipment in all instrument clusters (Fig. 23). The
odometer, trip odometer, and engine hours informa-
tion are displayed in a common electronic, blue-green
Vacuum-Fluorescent Display (VFD). The VFD is sol-
dered onto the cluster electronic circuit board and is
visible through a window with a smoked clear lens
located on the lower edge of the tachometer gauge
dial face of the cluster overlay. The dark lens over
the VFD prevents it from being clearly visible when
it is not illuminated. However, the odometer, trip
odometer, and engine hours information are not dis-
played simultaneously. The trip odometer reset
switch on the instrument cluster circuit board toggles
the display between odometer and trip odometer
modes by depressing the odometer/trip odometer
switch button that extends through the lower edge of
the cluster lens, just left of the odometer VFD. When
the trip odometer information is displayed, the word
ªTRIPº is also illuminated in the upper right corner
of the VFD in a blue-green color and at the same
lighting level as the trip odometer information. The
engine hours information replaces the selected odom-
eter or trip odometer information whenever the igni-
tion switch is in the On position and the engine is
not running.
The odometer, trip odometer, and engine hours
information is stored in the instrument cluster mem-
ory. This information can be increased when the
proper inputs are provided to the instrument cluster,
but the information cannot be decreased. The odom-
eter can display values up to 999,999 kilometers
(999,999 miles). The odometer latches at these val-
ues, and will not roll over to zero. The trip odometer
can display values up to 9,999.9 kilometers (9,999.9
miles) before it rolls over to zero. The odometer dis-
play does not have a decimal point and will not show
values less than a full unit (kilometer or mile), while
the trip odometer display 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 odometer display is not shown in
the VFD. The unit of measure for the instrument
cluster odometer/trip odometer is selected at the time
that it is manufactured, and cannot be changed.
Engine hours are displayed in the format, ªhr9999º.The cluster will accumulate values up to 9,999 hours
before the display rolls over to zero.
The odometer has a ªRental Carº mode, which will
illuminate the odometer information in the VFD
whenever the driver side front door is opened with
the ignition switch in the Off or Accessory positions.
During daylight hours (exterior lamps are Off) the
VFD is illuminated at full brightness for clear visibil-
ity. At night (exterior lamps are On) the VFD lighting
level is adjusted with the other cluster illumination
lamps using the panel lamps dimmer thumbwheel on
the headlamp switch. However, a ªParadeº mode
position of the panel lamps dimmer thumbwheel
allows the VFD to be illuminated at full brightness if
the exterior lamps are turned On during daylight
hours.
The VFD, the trip odometer switch, and the trip
odometer switch 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. The engine hours give an indication of the
cumulative engine-on time. This indicator is con-
trolled by the instrument cluster circuitry based
upon cluster programming and electronic messages
received by the cluster from the Powertrain Control
Module (PCM) over the Programmable Communica-
tions Interface (PCI) data bus. The odometer, trip
odometer and engine hours information is displayed
by the instrument cluster Vacuum Fluorescent Dis-
play (VFD). The VFD will display the odometer infor-
mation whenever any door is opened with the
ignition switch in the Off or Accessory positions, and
will display the last previously selected odometer or
trip odometer information when the ignition switch is
turned to the On or Start positions. The instrument
cluster circuitry controls the VFD and provides the
following features:
²Odometer/Trip Odometer Display Toggling-
Actuating the trip odometer reset switch button
momentarily with the VFD illuminated will toggle
the display between the odometer and trip odometer
information. Each time the VFD 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).
²Engine Hours Display Toggling- When the
trip odometer reset switch button is pressed and held
for longer than about six seconds with the ignition
switch in the On position and the engine speed mes-
sage from the PCM is zero, the trip odometer infor-
mation will be momentarily displayed, then the
engine hours information will be displayed. The VFD
must be displaying the odometer information when
Fig. 23 Odometer Display
8J - 32 INSTRUMENT CLUSTERDR

LAMPS/LIGHTING - INTERIOR
TABLE OF CONTENTS
page page
DOME LAMP
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................26
INSTALLATION.........................26
DOOR AJAR SWITCH
DESCRIPTION.........................27
OPERATION...........................27GLOVE BOX LAMP/SWITCH
REMOVAL.............................27
INSTALLATION.........................28
READING LAMP
DESCRIPTION.........................28
OPERATION...........................28
REMOVAL.............................28
INSTALLATION.........................29
DOME LAMP
DESCRIPTION
The dome lamp is controlled by the instrument
cluster which provides power at all times, regardless
of the ignition switch position. The ground circuit for
the lamp is switched through the integral dome lamp
switch or through the door ajar switches via the
instrument cluster.
The dome lamp lens and bulb are available for ser-
vice replacement. If either of the lamp switch or bulb
holders is faulty or damaged, the dome lamp assem-
bly must be replaced.
For service of the dome lamp bulb, refer to the
appropriate wiring information.
OPERATION
The dome lamp is activated by the door ajar
switches via the instrument cluster. When all of the
doors are closed, the lamp can be activated by
depressing the lens. When any door is open, depress-
ing the lamp lense to activate the lamp switch will
not turn the lamps off.
The instrument cluster monitors the door ajar
switches. When a door is open the instrument cluster
grounds the low side drivers to turn on the lamp.
Upon closing all doors, the instrument cluster ini-
tiates a 30 second timer. If any of the doors are
opened during the ªtime outº cycle, the instrument
cluster will reset the timer until all doors are closed.
The instrument cluster will faid to off when the doors
are closed and the ignition is turned ON, the time
out expires or the power locks are activated.
REMOVAL
(1) Using a small flat blade, pry the left side (driv-
er's side) of the dome lamp lens downward from
dome lamp.(2) Allow the lens to hang down (Fig. 1), this will
disengage the right side of the lamp (passenger's
side) from the headliner.
(3) Pull the right side of the lamp down and slide
the lamp to the right (Fig. 2).
(4) Separate the lamp from the headliner.
(5) Disengage dome lamp wire connector from body
wire harness.
(6) Separate dome lamp from vehicle.
INSTALLATION
(1) Position dome lamp at headliner.
(2) Connect dome lamp wire connector to body
wire harness.
(3) Position the left side of the lamp in the head-
liner opening and slide lamp to the left (Fig. 1).
Fig. 1 Dome Lamp Lens
1 - HEADLINER
2 - CONNECTOR
3 - DOME LAMP
4 - LENS
5 - BULB
8L - 26 LAMPS/LIGHTING - INTERIORDR

INSTALLATION
(1) Reach through the glove box opening and
behind the glove box lamp and switch mounting
bracket to feed the instrument panel wire harness
connectors out through the hole in the glove box
lamp and switch housing mounting bracket.
(2) Position the glove box lamp and switch unit to
the instrument panel.
(3) Reconnect the instrument panel wire harness
connector to the connector receptacle on the back of
the glove box lamp and switch unit.
(4) Push the glove box lamp and switch unit into
the hole in the mounting bracket on the instrument
panel glove box opening upper reinforcement.
(5) Install the glove box onto the instrument panel.
(Refer to 23 - BODY/INSTRUMENT PANEL/GLOVE
BOX - INSTALLATION) for the procedures.
(6) Close the glove box.
(7) Reconnect the battery negative cable.
READING LAMP
DESCRIPTION
The overhead console in this vehicle is equipped
with two individual reading and courtesy lamps. The
lamp lenses are the only visible components of these
lamps. Each lamp has its own switch, bulb, reflector
and lens within the overhead console.
The overhead console reading and courtesy lamps
are controlled by the instrument cluster which pro-
vides power at all times, regardless of the ignition
switch position. The ground circuit for the lamps is
switched through the integral reading and courtesy
lamp switches or through the door ajar switches.
Each lamp is designed and aimed to provide illumi-
nation that will be directed only to that side of the
vehicle on which the lamp is located.
The reading and courtesy lamp lenses and bulbs
are available for service replacement. The reading
and courtesy lamp switches, bulb holders and wiring
are only available as part of the overhead console
wire harness. If either of the lamp switches or bulb
holders is faulty or damaged, the entire overhead
console wire harness assembly must be replaced.
For service of the reading and courtesy lamp bulbs,
refer to the appropriate wiring information.
OPERATION
All reading and courtesy lamps located in the over-
head console are activated by the door ajar switches
via the instrument cluster. When all of the doors are
closed, these lamps can be individually activated by
depressing the corresponding lens. When any door is
open, depressing the lamp lenses to activate the lamp
switches will not turn the lamps off.The instrument cluster monitors the door ajar
switches. When a door is open the instrument cluster
grounds the low side drivers to turn on the lamps.
Upon closing all doors, the instrument cluster ini-
tiates a 30 second timer. If any of the doors are
opened during the ªtime outº cycle, the instrument
cluster will reset the timer until all doors are closed.
The instrument cluster will faid to off when the doors
are closed and the ignition is turned ON, the time
out expires or the power locks are activated.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Insert a long, narrow, flat-bladed tool between
the curved (outboard) edge of the reading and cour-
tesy lamp lens and the overhead console housing
(Fig. 4).
(3) Gently pry inward and downward against the
lens until the latch tab in the center of the outboard
edge of the reading and courtesy lamp lens is disen-
gaged from the overhead console housing.
(4) Pull firmly on the lens toward the outboard
side of the vehicle to disengage the two pivot tabs on
the inboard edge of the reading and courtesy lamp
lens are disengaged from the overhead console hous-
ing.
(5) Remove the reading and courtesy lamp lens
from the overhead console housing.
Fig. 4 Overhead Console Reading Lamp Bulb
Removal
1 - LENS
2 - FLAT BLADE
3 - CONSOLE
8L - 28 LAMPS/LIGHTING - INTERIORDR
GLOVE BOX LAMP/SWITCH (Continued)

The electronic compass unit features a self-cali-
brating design, which simplifies the calibration pro-
cedure. This feature automatically updates the
compass calibration while the vehicle is being driven.
This allows the compass unit to compensate for small
changes in the residual magnetism that the vehicle
may acquire during normal use. If the compass read-
ings appear to be erratic or out of calibration, per-
form the following calibration procedure. Also, new
service replacement Electronic Modules (EVIC,
CMTC) must have their compass calibrated using
this procedure. Do not attempt to calibrate the com-
pass near large metal objects such as other vehicles,
large buildings, or bridges; or, near overhead or
underground power lines.
NOTE: Whenever the compass is calibrated manu-
ally, the variance number must also be reset. Refer
to Compass Variation Adjustment in this group.
To calibrate the compass manually proceed as fol-
lows:
(1) Turn the ignition switch to the On position. If
the compass/temperature data is not currently being
displayed, momentarily depress and release the C/T
push button to reach the compass/temperature dis-
play.
(2) Depress the RESET push button and hold the
button down until ªCALº appears in the display. This
takes about ten seconds, and appears about five sec-
onds after ªVAR = XXº is displayed.
(3) Release the RESET push button.
(4) Drive the vehicle on a level surface, away from
large metal objects and power lines, through three or
more complete turns at between five and eight kilo-
meters-per-hour (three and five miles-per-hour) in
not less than 48 seconds. The ªCALº message will
disappear from the display to indicate that the com-
pass is now calibrated.
NOTE: If the ªCALº message remains in the display,
either there is excessive magnetism near the com-
pass, or the unit is faulty. Repeat the calibration
procedure one more time.
NOTE: If the wrong direction is still indicated in the
compass display, the area selected for calibration
may be too close to a strong magnetic field. Repeat
the calibration procedure in another location.STANDARD PROCEDURE - COMPASS
DEMAGNETIZING
A degaussing tool (Special Tool 6029) is used to
demagnetize, or degauss, the overhead console for-
ward mounting screw and the roof panel above the
overhead console. Equivalent units must be rated as
continuous duty for 110/115 volts and 60 Hz. They
must also have a field strength of over 350 gauss at 7
millimeters (0.25 inch) beyond the tip of the probe.
To demagnetize the roof panel and the overhead
console forward mounting screw, proceed as follows:
(1) Be certain that the ignition switch is in the Off
position, before you begin the demagnetizing proce-
dure.
(2) Connect the degaussing tool to an electrical
outlet, while keeping the tool at least 61 centimeters
(2 feet) away from the compass unit.
(3) Slowly approach the head of the overhead con-
sole mounting screw with the degaussing tool con-
nected.
(4) Contact the head of the screw with the plastic
coated tip of the degaussing tool for about two sec-
onds.
(5) With the degaussing tool still energized, slowly
back it away from the screw. When the tip of the tool
is at least 61 centimeters (2 feet) from the screw
head, disconnect the tool.
(6) Place a piece of paper approximately 22 by 28
centimeters (8.5 by 11 inches), oriented on the vehicle
lengthwise from front to rear, on the center line of
the roof at the windshield header (Fig. 3). The pur-
pose of the paper is to protect the roof panel from
scratches, and to define the area to be demagnetized.
(7) Connect the degaussing tool to an electrical
outlet, while keeping the tool at least 61 centimeters
(2 feet) away from the compass unit.
(8) Slowly approach the center line of the roof
panel at the windshield header, with the degaussing
tool connected.
(9) Contact the roof panel with the plastic coated
tip of the degaussing tool. Be sure that the template
is in place to avoid scratching the roof panel. Using a
slow, back-and-forth sweeping motion, and allowing
13 millimeters (0.50 inch) between passes, move the
tool at least 11 centimeters (4 inches) to each side of
the roof center line, and 28 centimeters (11 inches)
back from the windshield header.
(10) With the degaussing tool still energized,
slowly back it away from the roof panel. When the
tip of the tool is at least 61 centimeters (2 feet) from
the roof panel, disconnect the tool.
(11) Calibrate the compass and adjust the compass
variance (Refer to 8 - ELECTRICAL/OVERHEAD
CONSOLE - STANDARD PROCEDURE).
8M - 4 MESSAGE SYSTEMSDR
OVERHEAD CONSOLE (Continued)