1998 DODGE RAM 1500 Vacuum

tioned at the relative engine speed position on the
gauge scale until the engine stops running, or until
the ignition switch is turned to the Off position,
whichever occurs first.
²Communication Error- If the cluster fails to
receive an engine speed 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 position, whichever occurs first. After three sec-
onds, the gauge needle will return to the left end of
the gauge scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the tachometer needle will
be swept to several calibration points on the gauge
scale in a prescribed sequence in order to confirm the
functionality of the gauge and the cluster control cir-
cuitry.
On vehicles with a gasoline engine, the PCM con-
tinually monitors the crankshaft position sensor to
determine the engine speed. On vehicles with a die-
sel engine, the ECM continually monitors the engine
speed sensor to determine the engine speed. The
PCM or ECM then sends the proper engine speed
messages to the instrument cluster. For further diag-
nosis of the tachometer or the instrument cluster cir-
cuitry that controls the gauge, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the
crankshaft position sensor, the engine speed sensor,
the PCM, the ECM, the PCI data bus, or the elec-
tronic message inputs to the instrument cluster that
control the tachometer, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
TOW/HAUL INDICATOR
DESCRIPTION
A tow/haul indicator is standard equipment on all
instrument clusters (Fig. 30). However, on vehicles
not equipped with the optional overdrive automatic
transmission, this indicator is electronically disabled.
The tow/haul indicator consists of the text ªTOW/
HAULº, which appears in the lower portion of the
odometer/trip odometer indicator Vacuum Fluores-
cent Display (VFD) unit. The VFD is soldered 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 VFDprevents the indicator from being clearly visible
when it is not illuminated. The text ªTOW/HAULº
appear in an amber color and at the same lighting
level as the odometer/trip odometer information
when they are illuminated by the instrument cluster
electronic circuit board. The tow/haul indicator is ser-
viced as a unit with the VFD in the instrument clus-
ter.
OPERATION
The tow/haul indicator gives an indication to the
vehicle operator when the Off position of the tow/
haul switch has been selected, disabling the electron-
ically controlled overdrive feature of the automatic
transmission. This indicator is controlled by the
instrument cluster circuit board based upon cluster
programming and electronic messages received by
the cluster from the Powertrain Control Module
(PCM) over the Programmable Communications
Interface (PCI) data bus. The tow/haul indicator 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 indicator will
always be off when the ignition switch is in any posi-
tion except On or Start. The indicator only illumi-
nates when it is switched to ground by the
instrument cluster circuitry. The instrument cluster
will turn on the tow/haul off indicator for the follow-
ing reasons:
²Tow/Haul Lamp-On Message- Each time the
cluster receives a tow/haul lamp-on message from the
PCM indicating that the Off position of the tow/haul
switch has been selected, the tow/haul indicator will
be illuminated. The indicator remains illuminated
until the cluster receives a tow/haul lamp-off mes-
sage 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 tow/haul indicator will
be turned on, then off again during the VFD portion
of the test to confirm the functionality of the VFD
and the cluster control circuitry.
The PCM continually monitors the tow/haul switch
to determine the proper outputs to the automatic
transmission. The PCM then sends the proper tow/
haul lamp-on and lamp-off messages to the instru-
ment cluster. For further diagnosis of the tow/haul
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 overdrive con-
trol system, the PCM, the PCI data bus, or the elec-
tronic message inputs to the instrument cluster that
control the tow/haul indicator, a DRBIIItscan tool is
Fig. 30 Tow/Haul Indicator
DRINSTRUMENT CLUSTER 8J - 39
TACHOMETER (Continued)

cator is electronically disabled. The upshift indicator
consists of an upward pointed arrow icon, which
appears on the right side of the electronic gear selec-
tor indicator Vacuum Fluorescent Display (VFD)
unit. The VFD is soldered onto the cluster electronic
circuit board and is visible through a window with a
smoked clear lens located on the lower edge of the
speedometer gauge dial face of the cluster overlay.
The dark lens over the VFD prevents the indicator
from being clearly visible when it is not illuminated.
The icon appears in a blue-green color and at the
same lighting level as the odometer/trip odometer
information when it is illuminated by the instrument
cluster electronic circuit board. The upshift indicator
is serviced as a unit with the instrument cluster.
OPERATION
The upshift indicator gives an indication to the
vehicle operator when the manual transmission
should be shifted to the next highest gear in order to
achieve the best fuel economy. This indicator is con-
trolled by the instrument cluster circuit board based
upon cluster programming and electronic messages
received by the cluster from the Powertrain Control
Module (PCM) on vehicles with a gasoline engine, or
from the Engine Control Module (ECM) on vehicles
with a diesel engine over the Programmable Commu-
nications Interface (PCI) data bus. The upshift indi-
cator 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 indi-
cator will always be off when the ignition switch is in
any position except On or Start. The indicator only
illuminates when it is switched to ground by the
instrument cluster circuitry. The instrument cluster
will turn on the upshift indicator for the following
reasons:
²Upshift Lamp-On Message- Each time the
cluster receives an upshift lamp-on message from the
PCM or ECM indicating the engine speed and load
conditions are right for a transmission upshift to
occur, the upshift indicator is illuminated. The indi-
cator remains illuminated until the cluster receives
an upshift lamp-off message from the PCM or ECM,
or until the ignition switch is turned to the Off posi-
tion, whichever occurs first. The PCM or ECM will
normally send an upshift lamp-off message three to
five seconds after a lamp-on message, if an upshift is
not performed. The indicator will then remain off
until the vehicle stops accelerating and is brought
back into the range of indicator operation, or until
the transmission is shifted into another gear.
²Actuator Test- Each time the cluster is put
through the actuator test, the upshift indicator willbe turned on, then off again during the VFD portion
of the test to confirm the functionality of the VFD
and the cluster control circuitry.
On vehicles with a gasoline engine, the PCM con-
tinually monitors the engine speed and load condi-
tions to determine the proper fuel and ignition
requirements. On vehicles with a diesel engine, the
ECM continually monitors the engine speed and load
conditions to determine the proper fuel requirements.
The PCM or ECM then sends the proper upshift indi-
cator lamp-on and lamp-off messages to the instru-
ment cluster. For further diagnosis of the upshift
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 PCM, the
ECM, the PCI data bus, or the electronic message
inputs to the instrument cluster that control the
upshift indicator, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
VOLTAGE GAUGE
DESCRIPTION
A voltage gauge is standard equipment on all
instrument clusters. The voltage gauge is located in
the upper left quadrant of the instrument cluster,
above the fuel gauge. The voltage gauge consists of a
movable gauge needle or pointer controlled by the
instrument cluster circuitry and a fixed 90 degree
scale on the cluster overlay that reads left-to-right
from ªLº (or Low) to ªHº (or High) for gasoline
engines. On vehicles with a diesel engine, the scale
reads from ª8º to ª18º volts. An International Control
and Display Symbol icon for ªBattery Charging Con-
ditionº is located on the cluster overlay, directly
below the right end of the gauge scale (Fig. 34). The
voltage gauge graphics are black against a white
field except for a single red graduation at each end of
the gauge scale, 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 black graphics appear blue and the
red graphics still appear red. The orange gauge nee-
dle is internally illuminated. Gauge illumination is
provided by replaceable incandescent bulb and bulb
holder units located on the instrument cluster elec-
tronic circuit board. The voltage gauge is serviced as
a unit with the instrument cluster.
Fig. 34 Battery Charging Condition Icon
8J - 42 INSTRUMENT CLUSTERDR
UPSHIFT INDICATOR (Continued)

BRAKE LAMP
REMOVAL
REMOVAL - WITH CARGO BOX
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the tail lamp unit (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/TAIL
LAMP UNIT - REMOVAL).
(3) Remove the lamp back plate from the tail lamp
unit.
(4) Release the brake lamp bulb locking tabs and
remove the bulb from the back plate.
REMOVAL - WITHOUT CARGO BOX
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the four screws that secure the tail
lamp lens to the tail lamp housing (Fig. 3).
(3) Separate the tail lamp lens from the tail lamp
housing.
(4) Push the brake lamp bulb inward and rotate it
counter-clockwise.
(5) Remove the brake lamp bulb from the brake
lamp socket.
INSTALLATION
INSTALLATION - WITH CARGO BOX
(1) Install the brake lamp bulb into the lamp back
plate.
(2) Install the lamp back plate onto the tail lamp
unit.
(3) Install the tail lamp unit (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/TAIL
LAMP UNIT - INSTALLATION).
(4) Reconnect the negative battery cable.
INSTALLATION - WITHOUT CARGO BOX
(1) Install the brake lamp bulb into the brake
lamp socket by pushing inward and rotating it clock-
wise.
NOTE: Install the tail lamp lens with the clear por-
tion (back-up lens) at the top of the housing. Make
sure that the gasket is correctly in place and not
twisted or torn.
(2) Position the tail lamp lens and gasket onto the
tail lamp unit.
NOTE: Do not overtighten the tail lamp lens screws
or damage to the tail lamp lens may result.
(3) Install the four screws that secure the tail
lamp lens to the tail lamp unit. Tighten the screws
securely.
(4) Reconnect the negative battery cable.
BRAKE LAMP SWITCH
DESCRIPTION
The plunger type brake lamp switch is mounted on
a bracket attached to the base of the steering col-
umn, under the instrument panel.
CAUTION: The switch can only be adjusted during
initial installation. If the switch is not adjusted prop-
erly a new switch must be installed.
OPERATION
The brake lamp switch is hard wired to the Center
High Mount Stop Lamp (CHMSL) and also moni-
tored by the Instrument Cluster for use by the brake
lamp, speed control brake sensor circuits and elec-
tronic brake distribution (EBD). The brake lamp cir-
cuit is open until the plunger is depressed. The speed
control and brake sensor circuits are closed until the
plunger is depressed. When the brake lamp switch
transitions, the CHMSL transitions and instrument
cluster transmits a brake applied/released message
on the bus. The Integrated Power Module (IPM) will
then transition the brake lamps.
When the brake light switch is activated, the Pow-
ertrain Control Module (PCM) receives an input indi-
cating that the brakes are being applied. After
receiving this input, the PCM maintains idle speed to
a scheduled rpm through control of the Idle Air Con-
trol (IAC) motor. The brake switch input is also used
to disable vent and vacuum solenoid output signals
to the speed control servo.
Fig. 3 Tail Lamp Lens
DRLAMPS/LIGHTING - EXTERIOR 8L - 9

Vehicles equipped with the speed control option use
a dual function brake lamp switch. The PCM moni-
tors the state of the dual function brake lamp switch.
The brake switch is equipped with three sets of
contacts, one normally open and the other two nor-
mally closed (brakes disengaged). The PCM sends a
12 volt signal to one of the normally closed contacts
in the brake switch, which is returned to the PCM as
a brake switch state signal. With the contacts closed,
the 12 volt signal is pulled to ground causing the sig-
nal to go low. The low voltage signal, monitored by
the PCM, indicates that the brakes are not applied.
When the brakes are applied, the contacts open,
causing the PCM's output brake signal to go high,
disengaging the speed control, cutting off PCM power
to the speed control solenoids.
The second set of normally closed contacts supplies
12 volts from the PCM any time speed control is
turned on. Through the brake switch, voltage is
routed to the speed control servo solenoids. The
speed control solenoids (vacuum, vent and dump) are
provided this voltage any time the speed control is
ON and the brakes are disengaged.
When the driver applies the brakes, the contacts
open and voltage is interrupted to the solenoids. The
normally open contacts are fed battery voltage. When
the brakes are applied, battery voltage is supplied to
the brake lamps.
The brake lamp switch can only be adjusted once.
That is at the initial installation of the switch. If the
switch is not adjusted properly or has been removed,
a new switch must be installed and adjusted.
DIAGNOSIS AND TESTING - BRAKE LAMP
SWITCH
The brake lamp switch can be tested with an ohm-
meter. The ohmmeter is used to check continuity
between the pin terminals (Fig. 4).
SWITCH CIRCUIT IDENTIFICATION
²Terminals 1 and 2: brake lamp circuit
²Terminals 3 and 4: RWAL/ABS module and Pow-
ertrain Control Module (PCM) circuit
²Terminals 5 and 6: speed control circuit
SWITCH CONTINUITY TEST
NOTE: Disconnect switch harness before testing
switch continuity.
With switch plunger extended, attach test leads to
pins 1 and 2. Replace switch if meter indicates no
continuity.
With switch plunger retracted, attach test leads to
pins 3 and 4. Replace switch if meter indicates no
continuity.With switch plunger retracted, attach test leads to
pins 5 and 6. Replace switch if meter indicates no
continuity.
REMOVAL
(1) Disconnect the switch harness (Fig. 5).
(2) Press and hold the brake pedal in applied posi-
tion.
(3) Rotate the switch counterclockwise about 30É to
align the switch lock tab with the notch in bracket.
(4) Pull the switch rearward out of the mounting
bracket and release the brake pedal.
Fig. 4 Brake Lamp Switch Terminal Identification
1 - TERMINAL PINS
2 - PLUNGER TEST POSITIONS
Fig. 5 Brake Lamp Switch & Bracket
1 - RELEASE LEVER
2 - BRACKET
3 - BRAKE PEDAL SUPPORT
4 - BRAKE LAMP SWITCH
8L - 10 LAMPS/LIGHTING - EXTERIORDR
BRAKE LAMP SWITCH (Continued)

The compass unit also will compensate for magne-
tism the body of the vehicle may acquire during nor-
mal use. However, avoid placing anything magnetic
directly on the roof of the vehicle. Magnetic mounts
for an antenna, a repair order hat, or a funeral pro-
cession flag can exceed the compensating ability of
the compass unit if placed on the roof panel. Mag-
netic bit drivers used on the fasteners that hold the
overhead console assembly to the roof header can
also affect compass operation. If the vehicle roof
should become magnetized, the demagnetizing and
calibration procedures found in this section may be
required to restore proper compass operation.
TEMPERATURE DISPLAY
All the available overhead consoles on this model
include Temperature information. The temperature
displays the outside ambient temperature in whole
degrees. The temperature display can be toggled
from Fahrenheit to Celsius by selecting the desired
U.S./Metric option from the customer programmable
features. The displayed temperature is not an instant
reading of conditions, but an average temperature. It
may take the temperature display several minutes to
respond to a major temperature change, such as driv-
ing out of a heated garage into winter temperatures.
When the ignition switch is turned to the Off posi-
tion, the last displayed temperature reading stays in
the electronic control modules, (CMTC, EVIC) mem-
ory. When the ignition switch is turned to the On
position again, the electronic module will display the
memory temperature for one minute; then update the
display to the current average temperature reading
within five minutes.The temperature function is supported by an ambi-
ent temperature sensor. This sensor is mounted out-
side the passenger compartment near the front and
center of the vehicle, and is hard wired to the Front
Control Module (FCM). The FCM sends temperature
status messages to the module over the J1850 PCI
data bus circuit. For more information on the ambi-
ent temperature sensor, refer to Ambient Tempera-
ture Sensor later in this section.
Following are general descriptions of the major
components used in the overhead console. Refer to
Wiring Diagrams for complete circuit schematics.
OPERATION
Refer to the vehicle Owner's Manual for specific
operation of each overhead console and its systems.
DIAGNOSIS AND TESTING - OVERHEAD
CONSOLE
If the problem with the overhead console is an
inaccurate or scrambled display, refer toSELF-DI-
AGNOSTIC TESTlater in this text. If the problem
with the overhead console is incorrect Vacuum Fluo-
rescent Display (VFD) dimming levels, use a DRB
IIItscan tool and the proper Diagnostic Procedures
manual to test for the correct dimming message
inputs being received from the Body Control Module
(BCM) or Front Control Module (FCM) over the
J1850 Programmable Communications Interface
(PCI) data bus circuit. If the problem is a no-display
condition, use the following procedure. For complete
circuit diagrams, refer toOverhead Consolein the
Wiring Diagrams section of the service manual.
(1) Remove the overhead console from the head-
liner (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL).
(2) Check for battery voltage at the overhead con-
sole electrical connector. Refer to Wiring for connec-
tor information. If OK, go to Step 3. If not OK, Check
for battery voltage at the appropriate B(+) fuse in the
integrated power module, repair the open fused B(+)
circuit as required.
(3) Turn the ignition switch to the On position.
Check the fused ignition switch output circuit(s) at
the overhead console electrical connector. If OK, go to
Step 4. If not OK, repair the open or shorted circuit
as required.
(4) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Check for continuity between the ground circuit cav-
ity of the overhead console electrical connector and a
good ground. There should be continuity. If OK, refer
toSELF-DIAGNOSTIC TESTbelow for further
diagnosis of the electronics module and the J1850
PCI data bus circuit. If not OK, repair the open
ground circuit as required.
Fig. 1 DR OVERHEAD CONSOLE ± EVIC
8M - 2 MESSAGE SYSTEMSDR
OVERHEAD CONSOLE (Continued)

(6) Depress and release theRESETpush button
to enter the displayed zone number into the EVIC/
CMTC module memory.
(7) Confirm that the correct directions are now
indicated by the compass.
REMOVAL
OVERHEAD CONSOLE REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the overhead console retaining screws,
located in the sunglass storage bin.
(3) Using your fingertips, grasp the sides of the
overhead console and pull straight down evenly to
disengage the two snap clips at the front of the unit.
(4) Lower the overhead console far enough to
access the wire harness connectors.
(5) Disconnect the EVIC, CMTC electronic module
and the reading/courtesy lamps electrical connectors.
(6) Remove the overhead console from the vehicle.
INSTALLATION
(1) Position the overhead console in the vehicle.
(2) Connect the EVIC, CMTC electronic module
and the reading/courtesy lamps electrical connectors.
(3) Grasp the sides of the overhead console and
push straight up evenly to engage the two snap clips
at the rear of the unit.
(4) Install the overhead console retaining screw,
located in the front of console. Torque the screw to
1.2 N´m (10 in. lbs.).
(5) Connect the negative battery cable.
COMPASS/MINI-TRIP
COMPUTER
DESCRIPTION
The Compass Mini-Trip Computer (CMTC) is a
module located in the overhead console. The CMTC is
equipped with a mini-trip feature. The CMTC con-
sists of a electronic control module with a vacuum
fluorescent display (VFD) and function switches. The
CMTC consists of a electronic module that displays
compass, trip computer, and temperature features.
Actuating the STEP push button will cause the
CMTC to change mode of operation when the ignition
is ON. Example:
²Average miles per gallon (ECO)
²Distance to empty (DTE)
²Trip odometer (ODO)
²Elapsed time (ET)
²OffActuating the C/T push button will cause the
CMTC to change to Compass/Temperature display.
OPERATION
The Compass Mini-Trip Computer module in the
overhead console has buttons used to select various
functions. The CMTC selector buttons will not oper-
ate until the ignition is in the RUN position.
When the ignition switch is first turned to the
RUN position the CMTC display;
²Returns to the last mode setting selected before
the ignition was last switched OFF.
DIAGNOSIS AND TESTING - COMPASS
MINI-TRIP COMPUTER
Compass Mini-Trip Computer (CMTC) data is
obtained from other electronic modules (CCN, FCM
and JTEC) on the J1850 Data Bus circuit. The
CMTC will display dashes (- -) for any of the screens
it did not receive the bus messages. The label corre-
sponding to the missing information will be lit. If no
compass mini-trip computer data is displayed, check
the J1850 Data Bus circuit communications and the
other modules.
Refer to Overhead Console Diagnosis and Testing
for instructions on performing a CMTC module Self-
Diagnostic Test. The DRB IIItis recommended for
checking the J1850 Data Bus circuit and the other
modules. Perform the CMTC self diagnosis before
replacing the CMTC module.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the overhead console from the headlin-
er.(Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL).
(3) Remove the screws holding Compass Mini-Trip
Computer module in the overhead console (Fig. 5).
(4) Disconnect the CMTC module electrical connec-
tor. Depress the retaining tab and pull straight
apart.
(5) Remove CMTC module from console assembly.
INSTALLATION
(1) Position the compass mini-trip computer mod-
ule in the overhead console.
(2) Install the screws holding the compass mini-
trip computer module in the overhead console.
(3) Connect the module electrical connector.
(4) Install the overhead console on the headlin-
er(Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - INSTALLATION).
(5) Connect the negative battery cable.
(6) Check CMTC module function.
8M - 6 MESSAGE SYSTEMSDR
OVERHEAD CONSOLE (Continued)

NOTE: If a new module has been installed, the com-
pass will have to be calibrated and the variance set.
Refer to Compass Variation Adjustment and Com-
pass Calibration in the Standard Procedures sec-
tion of this group for the procedures.
ELECTRONIC VEHICLE INFO
CENTER
DESCRIPTION
The Electronic Vehicle Information Center (EVIC)
is a module located in the overhead console on some
models. The EVIC module features a large Vacuum
Fluorescent Display (VFD) screen for displaying
information, and back-lit push button switches
labeled C/T (compass/temperature), RESET, STEP,
and MENU.
The EVIC module contains a central processing
unit and interfaces with other electronic modules in
the vehicle over the Programmable Communications
Interface (PCI) J1850 data bus circuit. The PCI data
bus circuit allows the sharing of sensor information.
This helps to reduce wire harness complexity, reduce
internal controller hardware, and reduce component
sensor current loads. At the same time, this system
provides increased reliability, enhanced diagnostics,
and allows the addition of many new feature capabil-
ities.The EVIC ªMenuº push button provides the vehicle
operator with a user interface, which allows the
selection of several optional customer programmable
electronic features to suit individual preferences.
Refer toELECTRONIC VEHICLE INFORMA-
TION CENTER PROGRAMMINGin the Standard
Procedures section of this group for more information
on the customer programmable feature options.
If the vehicle is equipped with the optional univer-
sal transmitter transceiver, the EVIC will also dis-
play messages and an icon indicating when the
universal transmitter transceiver is being trained,
which of the three transmitter buttons is transmit-
ting, and when the transceiver is cleared.
Data input for all EVIC functions, including VFD
dimming level, is received through the J1850 PCI
data bus circuit. The EVIC module uses its internal
programming and all of its data inputs to calculate
and display the requested data. If the data displayed
is incorrect, perform the self-diagnostic tests as
described in this group. If these tests prove inconclu-
sive, the use of a DRB IIItscan tool and the proper
Diagnostic Procedures manual are recommended for
further testing of the EVIC module and the J1850
PCI data bus circuit.
The EVIC module cannot be repaired, and is avail-
able for service only as a unit. If any part is faulty or
damaged, the complete EVIC module must be
replaced.
OPERATION
The Electronic Vehicle Information Center is wired
to both constant 12v and ignition switched sources of
battery current so that some of its features remain
operational at any time, while others may only oper-
ate with the ignition switch in the On position. When
the ignition switch is turned to the On position, the
EVIC module display will return to the last function
being displayed before the ignition was turned to the
Off position.
The compass/temperature display is the normal
EVIC display. With the ignition switch in the On
position, momentarily depressing and releasing the
C/T (compass/temperature) push button switch will
cause the EVIC to return to the compass/tempera-
ture display mode from any other mode. While in the
compass/temperature display mode, momentarily
depressing and releasing the Step push button will
step through the available trip computer display
options.
The EVIC trip computer features several functions
that can be reset. The functions that can be reset
are: average fuel economy, trip odometer and elapsed
time. With the ignition switch in the On position and
with one of the functions of the trip computer that
can be reset currently displayed, depressing the
Fig. 5 OVERHEAD CONSOLE MODULE REMOVAL
1 - COMPASS MINI-TRIP COMPUTER MODULE
2 - OVERHEAD CONSOLE
DRMESSAGE SYSTEMS 8M - 7
COMPASS/MINI-TRIP COMPUTER (Continued)

AIRBAG SQUIB STATUS
IF the Active DTC is: Conditions Squib Status
Driver or Passenger Squib 1
openANDthe stored DTC minutes for both Driver or
Passenger squibs are within 15 minutes of each
otherBoth Squib 1 and 2 were
used.
Driver or Passenger Squib 2
open
Driver or Passenger Squib 1
openANDthe stored DTC minutes for Driver or
Passenger Squib 2 open is GREATER than the
stored DTC minutes for Driver or Passenger
Squib 1 by 15 minutes or moreSquib 1 was used; Squib 2 is
live.
Driver or Passenger Squib 2
open
Driver or Passenger Squib 1
openANDthe stored DTC minutes for Driver or
Passenger Squib 1 open is GREATER than the
stored DTC minutes for Driver or Passenger
Squib 2 by 15 minutes or moreSquib 1 is live; Squib 2 was
used.
Driver or Passenger Squib 2
open
Driver or Passenger Squib 1
openANDDriver or Passenger Squib 2 open is NOT
an active codeSquib 1 was used; Squib 2 is
live.
Driver or Passenger Squib 2
openANDDriver or Passenger Squib 1 open is NOT
an active codeSquib 1 is live; Squib 2 was
used.
Ifnone of the Driver or Passenger Squib 1 or 2
open are active codes, the status of the airbag squibs
is unknown. In this case the airbag should be han-
dled and disposed of as if the squibs were both live.
CLEANUP PROCEDURE
Following a supplemental restraint deployment,
the vehicle interior will contain a powdery residue.
This residue consists primarily of harmless particu-
late by-products of the small pyrotechnic charge that
initiates the propellant used to deploy a supplemen-
tal restraint. However, this residue may also contain
traces of sodium hydroxide powder, a chemical
by-product of the propellant material that is used to
generate the inert gas that inflates the airbag. Since
sodium hydroxide powder can irritate the skin, eyes,
nose, or throat, be certain to wear safety glasses,
rubber gloves, and a long-sleeved shirt during
cleanup (Fig. 3).
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, IF YOU EXPERIENCE SKIN IRRITATION
DURING CLEANUP, RUN COOL WATER OVER THE
AFFECTED AREA. ALSO, IF YOU EXPERIENCE
IRRITATION OF THE NOSE OR THROAT, EXIT THE
VEHICLE FOR FRESH AIR UNTIL THE IRRITATION
CEASES. IF IRRITATION CONTINUES, SEE A PHYSI-
CIAN.
(1) Begin the cleanup by using a vacuum cleaner
to remove any residual powder from the vehicle inte-
rior. Clean from outside the vehicle and work your
way inside, so that you avoid kneeling or sitting on a
non-cleaned area.(2) Be certain to vacuum the heater and air condi-
tioning outlets as well (Fig. 4). Run the heater and
air conditioner blower on the lowest speed setting
and vacuum any powder expelled from the outlets.
Fig. 3 Wear Safety Glasses and Rubber Gloves -
Typical
8O - 8 RESTRAINTSDR
RESTRAINTS (Continued)