display DODGE TOWN AND COUNTRY 2001 Owner's Manual

AUTO SHUT DOWN RELAY
DESCRIPTION
The relay is located in the Power Distribution Cen-
ter (PDC). For the location of the relay within the
PDC, refer to the PDC cover for location. Check elec-
trical terminals for corrosion and repair as necessary
OPERATION
The ASD sense circuit informs the PCM when the
ASD relay energizes. A 12 volt signal at this input
indicates to the PCM that the ASD has been acti-
vated. This input is used only to sense that the ASD
relay is energized.
When energized, the ASD relay supplies battery
voltage to the fuel injectors, ignition coils and the
heating element in each oxygen sensor. If the PCM
does not receive 12 volts from this input after
grounding the ASD relay, it sets a Diagnostic Trouble
Code (DTC).
When energized, the ASD relay provides power to
operate the injectors, ignition coil, generator field, O2
sensor heaters (both upstream and downstream), and
also provides a sense circuit to the PCM for diagnos-
tic purposes. The PCM energizes the ASD any time
there is a Crankshaft Position sensor signal that
exceeds a predetermined value. The ASD relay can
also be energized after the engine has been turned
off to perform an O2 sensor heater test, if vehicle is
equipped with OBD II diagnostics.
As mentioned earlier, the PCM energizes the ASD
relay during an O2 sensor heater test. This test is
performed only after the engine has been shut off.
The PCM still operates internally to perform several
checks, including monitoring the O2 sensor heaters.
CAMSHAFT POSITION
SENSOR
DESCRIPTION
The camshaft position sensorfor the 3.3/3.8L is
mounted in the front of the timing case cover (Fig. 7)
and the camshaft position sensor for the 2.4L is
mounted on the end of the cylinder head (Fig. 4).
OPERATION
The camshaft position sensor provides cylinder
identification to the Powertrain Control Module
(PCM) (Fig. 2). The sensor generates pulses as
groups of notches on the camshaft sprocket pass
underneath it (Fig. 3). The PCM keeps track of
crankshaft rotation and identifies each cylinder by
the pulses generated by the notches on the camshaftsprocket. Four crankshaft pulses follow each group of
camshaft pulses.
When the PCM receives 2 cam pulses followed by
the long flat spot on the camshaft sprocket, it knows
that the crankshaft timing marks for cylinder 1 are
next (on driveplate). When the PCM receives one
camshaft pulse after the long flat spot on the
sprocket, cylinder number 2 crankshaft timing marks
are next. After 3 camshaft pulses, the PCM knows
cylinder 4 crankshaft timing marks follow. One cam-
shaft pulse after the 3 pulses indicates cylinder 5.
The 2 camshaft pulses after cylinder 5 signals cylin-
der 6 (Fig. 3). The PCM can synchronize on cylinders
1or4.
When metal aligns with the sensor, voltage goes
low (less than 0.3 volts). When a notch aligns with
the sensor, voltage switches high (5.0 volts). As a
group of notches pass under the sensor, the voltage
switches from low (metal) to high (notch) then back
to low. The number of notches determine the amount
of pulses. If available, an oscilloscope can display the
square wave patterns of each timing event.
Top Dead Center (TDC) does not occur when
notches on the camshaft sprocket pass below the cyl-
inder. TDC occurs after the camshaft pulse (or
pulses) and after the 4 crankshaft pulses associated
with the particular cylinder. The arrows and cylinder
call outs on Figure 4 represent which cylinder the
flat spot and notches identify, they do not indicate
TDC position.
REMOVAL - 2.4L
The camshaft position sensor is mounted to the
rear of the cylinder head.
(1) Remove the negative battery cable.
Fig. 2 Camshaft Position Sensor
1 - ELECTRICAL CONNECTOR
2 - O-RING
3 - PAPER SPACER
RSIGNITION CONTROL8I-3
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INSTRUMENT CLUSTER
TABLE OF CONTENTS
page page
INSTRUMENT CLUSTER
DESCRIPTION............................1
OPERATION.............................1
DIAGNOSIS AND TESTING..................1
INSTRUMENT CLUSTER..................1
REMOVAL..............................11
INSTALLATION...........................11
CLUSTER LENS
REMOVAL..............................12INSTALLATION...........................12
MECHANICAL TRANSMISSION RANGE
INDICATOR
REMOVAL..............................12
INSTALLATION...........................12
RED BRAKE WARNING INDICATOR
DESCRIPTION...........................12
OPERATION.............................12
INSTRUMENT CLUSTER
DESCRIPTION
The instrumentation gauges are contained in a
subdial assembly within the instrument cluster. The
individual gauges are not serviceable. If one of the
cluster gauges becomes faulty, the entire cluster
would require replacement.
The mechanical instrument cluster with a tachom-
eter is equipped with a electronic vacuum fluorescent
transmission range indicator (PRND3L), odometer,
and trip odometer display.
The mechanical instrument cluster without a
tachometer is equipped with a cable operated trans-
mission range indicator (PRND21) and a vacuum
flourescent odometer display.
The instrument cluster is equipped with the follow-
ing warning lamps.
²Lift Gate Ajar
²Low Fuel Level
²Low Windshield Washer Fluid Level
²Cruise
²Battery Voltage
²Fasten Seat Belt
²Door Ajar
²Headlamp Out
²Coolant Temperature
²Anti-Lock Brake
²Brake
²Airbag
²Traction Control
²Autostick
OPERATION
Refer to the vehicle Owner's Manual for operation
instructions and conditions for the Instrument Clus-
ter Gauges.
DIAGNOSIS AND TESTING - SELF-
DIAGNOSTICS
The instrument clusters are equipped with a self
diagnostic test feature to help identify electronic
problems. Prior to any test, perform the Self-Diag-
nostic Test. The self diagnostic system displays
instrument cluster stored fault codes in the odometer
display, sweeps the gauges to the calibration points,
and bulb checks the warning indicators. When the
key is in the ON position with the engine not run-
ning, the MIL will remain illuminated for regulatory
purposes.
To activate the Self-Diagnostic program:
(1) With the ignition switch in the OFF position,
depress the TRIP ODOMETER RESET button.
(2) Continue to hold the TRIP ODOMETER
RESET button untilSofand a number (software ver-
sion number (i.e.Sof 3.2) appears in the odometer
window (about five seconds) then release the button.
If a fault code is present, the cluster will display it in
the odometer display. When all fault codes have been
displayed, the cluster will displayªendºin the odom-
eter display. Refer to the table to determine what
each trouble code means.
RSINSTRUMENT CLUSTER8J-1
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INSTRUMENT CLUSTER DTC'S
DTC DESCRIPTION
100.00 LOOP-BACK FAILURE
100.1 ABS COMMUNICATION FAULT
100.2 BCM COMMUNICATION FAULT
100.3 EATX COMMUNICATION FAULT
100.4 PCM COMMUNICATION FAULT
100.5 ORC COMMUNICATION FAULT
100.6 SBEC/DEC/MCM COMMUNICATION
FAULT
200.0 AIRBAG LED SHORT
200.1 AIRBAG LED OPEN
200.2 ABS LED SHORT
200.3 ABS LED OPEN
200.6 EL INVERTER TIME-OUT
200.7 EATX MISMATCH
DIM TEST
When CHEC-0 is displayed in the odometer win-
dow, the cluster's Vacuum Fluorescent (VF) displays
will dim down. If the VF display brightness does not
change, a problem exists in the cluster.
CALIBRATION TEST
When CHEC-1 is displayed in the odometer win-
dow, each of the cluster's gauge pointers will move
sequentially through each calibration point. The
table contains the proper calibration points for each
gauge. If the gauge pointers are not calibrated, a
problem exists in the cluster. If any gauge is out of
calibration, replace the cluster.
CLUSTER CALIBRATION
SPEEDOMETER CALIBRATION POINT
1 0 MPH (0 KM/H)
2 20 MPH (40 KM/H)
3 60 MPH (100 KM/H)
4 100 MPH (160 KM/H)
TACHOMETER
1 0 RPM
2 1000 RPM
3 3000 RPM
4 6000 RPM
FUEL GAUGE
1 EMPTY
2 1/4 FILLED
3 1/2 FILLED
4 FULL
TEMPERATURE
GAUGE
1 COLD
2 1/4
3 3/4
4 HOT
ODOMETER SEGMENT TEST
When CHEC-2 is displayed in the odometer win-
dow, each digit of the odometer will illuminate
sequentially. If a segment in the odometer does not
illuminate normally, a problem exists in the display.
ELECTRONIC TRANSMISSION RANGE INDICATOR
SEGMENT TEST
When CHEC-3 is displayed in the odometer win-
dow, each segment of the transmission range indica-
tor will illuminate sequentially. If a segment in the
transmission range indicator does not illuminate nor-
mally, a problem exists in the display board.
8J - 2 INSTRUMENT CLUSTERRS
INSTRUMENT CLUSTER (Continued)
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CONDITIONS
Refer to the following tables for possible problems,
causes, and corrections.
²INSTRUMENT CLUSTER
²SPEEDOMETER DIAGNOSIS
²TACHOMETER DIAGNOSIS
²FUEL GAUGE DIAGNOSIS
²TEMPERATURE GAUGE DIAGNOSIS²ODOMETER DIAGNOSIS
²ELECTRONIC GEAR INDICATOR DISPLAY
DIAGNOSIS
²MECHANICAL TRANSMISSION RANGE INDI-
CATOR (PRND21) DIAGNOSIS
NOTE: Always check the functionality of the cluster
by running the self test prior to troubleshooting.
INSTRUMENT CLUSTER
CONDITION POSSIBLE CAUSES CORRECTION
INSTRUMENT CLUSTER
INOPERATIVE.
NO RESPONSE FROM
INSTRUMENT CLUSTER.NO PCI BUS MESSAGES
FROM THE BCM.1. USE A DRB IIITSCAN TOOL TO CHECK THE
BCM. IF OK, LOOK FOR ANOTHER POSSIBLE
CAUSE FOR CLUSTER FAILURE. IF NOT OK,
REFER TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL.
SPREAD TERMINAL(S)
ON WIRING HARNESS
CLUSTER CONNECTOR.1. REMOVE CLUSTER FROM INSTRUMENT PANEL
AND CHECK WIRING HARNESS CONNECTOR FOR
SPREAD TERMINAL. IF OK, LOOK FOR ANOTHER
POSSIBLE CAUSE FOR THE CLUSTER FAILURE. IF
NOT OK, REPAIR CONNECTOR.
BCM IS NOT RECEIVING
PROPER INPUT FROM
THE IGNITION SWITCH.1. USE A DRB IIITSCAN TOOL TO VERIFY IGNITION
SWITCH STATUS INTO THE BCM. IF NOT OK, GO
TO STEP (2). IF OK, LOOK AT ANOTHER POSSIBLE
CAUSE OF FAILURE.
2. CHECK IGNITION SWITCH FUNCTION AND
WIRING.
INTERNAL CLUSTER
FAILURE.1. REPLACE CLUSTER.
WAKE UP CIRCUIT
FAULTY.VERIFY CONTINUITY OF WAKE UP CIRCUIT FROM
BCM TO MIC. CIRCUIT SHALL BE LOW WHENEVER
BCM IS AWAKE.
POWER OR GROUND
MISSING.IF NO RESPONSE FROM THE MIC, CHECK FOR
POWER AND GROUND AT THE MIC CONNECTOR.
REFER TO WIRING DIAGRAMS FOR CONNECTOR
CALL OUTS.
RSINSTRUMENT CLUSTER8J-3
INSTRUMENT CLUSTER (Continued)
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CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE
INACCURATE.1. TEMPERATURE
GAUGE OUT OF
CALIBRATION.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST.
²IF POINTER IS ACCURATE TO THE CALIBRATION
POINTS LOOK FOR ANOTHER POSSIBLE CAUSE
OF FAILURE.
²IF POINTER IS INACCURATE TO THE
CALIBRATION POINTS, REPLACE CLUSTER
ASSEMBLY.
2. COOLANT SENSOR
OUT OF CALIBRATION.2. REFER TO FUEL, COOLANT TEMPERATURE
SENSOR FOR TEST AND REPAIR PROCEDURE.
ODOMETER DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO DISPLAY 1. NO PCI BUS
ODOMETER MESSAGE
FROM BCM.1. USE A DRB IIITSCAN TOOL TO CHECK THE
BCM. REFER TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE
AND REPAIR.
2. INTERNAL CLUSTER
FAILURE.2. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF ODOMETER PASSES THE SEGMENT CHECK,
LOOK FOR ANOTHER POSSIBLE CAUSE OF
FAILURE. IF IT FAILS VERIFY POWER AND
GROUND ARE BEING PROVIDED TO THE
CLUSTER. IF YES, REPLACE CLUSTER. IF NO,
DETERMINE CAUSE OF NO POWER OR GROUND.
ERRATIC DISPLAY 1. INTERNAL CLUSTER
FAILURE.1.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF ODOMETER PASSES THE SEGMENT TEST,
FAILURE MAY NOT BE IN THE CLUSTER. LOOK
FOR ANOTHER POSSIBLE CAUSE OF FAILURE.
VERIFY GOOD POWER AND GROUND
CONNECTIONS. IF CONNECTIONS ARE GOOD AND
NO OTHER PROBLEMS ARE FOUND, REPLACE
CLUSTER ASSEMBLY.
2. BAD PCI BUS
MESSAGE FROM THE
BCM.2. USE A DRB IIITSCAN TOOL TO CHECK THE
BCM. REFER TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE
AND REPAIR.
ODOMETER WON'T GO
INTO TRIP MODE.1. TRIP SWITCH
DOESN'T WORK.1. IF CLUSTER WILL NOT GO INTO SELF
DIAGNOSTIC MODE AND CANNOT TOGGLE
BETWEEN ODOMETER AND TRIP ODOMETER,
REPLACE CLUSTER.
TRIP ODOMETER WON'T
RESET.1. RESET SWITCH
DOESN'T WORK.1. IF CLUSTER WILL NOT GO INTO SELF
DIAGNOSTIC MODE AND TRIP ODOMETER WILL
NOT RESET, REPLACE CLUSTER.
RSINSTRUMENT CLUSTER8J-9
INSTRUMENT CLUSTER (Continued)
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ELECTRONIC GEAR INDICATOR DISPLAY DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO DISPLAY 1. INTERNAL CLUSTER
FAILURE.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF PRND3L (PRND1234 IF AUTOSTICK
EQUIPPED) PASSES THE SEGMENT CHECK, THEN
FAILURE MAY NOT BE IN THE CLUSTER. LOOK
FOR ANOTHER POSSIBLE CAUSE OF FAILURE. IF
IT FAILS, REPLACE CLUSTER ASSEMBLY.
ERRATIC DISPLAY 1. INTERNAL CLUSTER
FAILURE.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF PRND3L (PRND1234 IF AUTOSTICK
EQUIPPED) PASSES THE SEGMENT CHECK, THEN
FAILURE MAY NOT BE IN THE CLUSTER. LOOK
FOR ANOTHER POSSIBLE CAUSE OF FAILURE.
2. BAD PCI BUS
MESSAGE FROM THE
TCM.2. USE A DRB IIITSCAN TOOL TO CHECK THE
TCM. REFER TO THE PROPER TRANSMISSION
DIAGNOSTIC PROCEDURES MANUAL TO
PROPERLY DIAGNOSE AND REPAIR.
ALL SEGMENTS ARE ON 1. NO PCI BUS
MESSAGE FROM THE
TCM.1.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST.
IF PRND3L (PRND1234 IF AUTOSTICK EQUIPPED)
PASSES TEST GO TO STEP 1.B. IF PRND3L
(PRND1234 IF AUTOSTICK EQUIPPED) FAILS TEST,
REFER TO THE PROPER TRANSMISSION
DIAGNOSTIC PROCEDURES MANUAL.
1.B. CHECK THE TCM USING A DRB IIITSCAN
TOOL. REFER TO THE PROPER TRANSMISSION
DIAGNOSTIC PROCEDURES MANUAL TO
PROPERLY DIAGNOSE AND REPAIR.
MECHANICAL TRANSMISSION RANGE INDICATOR (PRND21) DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
INDICATOR DOES NOT
SHOW PROPER GEAR
OR NO INDICATION.MIS-ADJUSTED 1.A. VERIFY TRANSMISSION SHIFT SYSTEM IS
CORRECTLY ADJUSTED.
1.B. VERIFY CORRECT ROUTING AND
ATTACHMENT OF PRNDL CABLE AND GUIDE TUBE.
1.C. RE-ADJUST PRNDL INDICATOR IN NEUTRAL
USING ADJUSTER WHEEL BELOW STEERING
COLUMN.
INDICATOR DOES NOT
FOLLOW GEAR SHIFT
LEVER.NOT ATTACHED 1.A. VERIFY INDICATOR CABLE CONNECTED TO
SHIFT LEVER PIN IN THE GROOVE.
1.B. VERIFY THAT THE INDICATOR CLIP IS SECURE,
AND ATTACHED TO THE MOUNTING BRACKET.
MAKE SURE THAT THE CLIP IS NOT BROKEN. IF
THE CLIP IS BROKEN, REPLACE CLIP ON
INDICATOR.
8J - 10 INSTRUMENT CLUSTERRS
INSTRUMENT CLUSTER (Continued)
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LAMPS/LIGHTING - INTERIOR
TABLE OF CONTENTS
page page
LAMPS/LIGHTING - INTERIOR
SPECIFICATIONS........................17
CENTER CONSOLE LAMP SWITCH
REMOVAL..............................18
INSTALLATION...........................18
CLUSTER ILLUMINATION LAMPS
REMOVAL..............................18
INSTALLATION...........................18
COURTESY LAMP
REMOVAL..............................18
INSTALLATION...........................18
DOME LAMP
REMOVAL..............................18INSTALLATION...........................18
GLOVE BOX LAMP SWITCH
REMOVAL..............................18
INSTALLATION...........................19
LIFTGATE LAMP
REMOVAL..............................19
INSTALLATION...........................19
READING LAMP
REMOVAL..............................19
INSTALLATION...........................20
VANITY LAMP
REMOVAL..............................20
INSTALLATION...........................20
LAMPS/LIGHTING - INTERIOR
SPECIFICATIONS
BULB APPLICATION TABLE
LAMP BULB
ABS LED
AIRBAG LED
ALARM SET PC74
AUTOSTICK VFD*
BRAKE SYSTEM WARNING LED
CONSOLE 194
CRUISE INDICATOR VFD*
DOME/RAIL LAMPS 578
DOOR AJAR INDICATOR LED
DOOR COURTESY LAMP 578
FRONT DOOR COURTESY 567
GLOVE BOX 194
HIGH BEAM INDICATOR
(BASE CLUSTER)LED
HIGH BEAM INDICATOR PC74
INSTRUMENT CLUSTER PC74
LIFTGATE 578
LIFTGATE AJAR LED
LAMP BULB
LOW FUEL INDICATOR LED
LOW WASHER FLUID
INDICATORLED
MALFUNCTION INDICATOR
(BASE CLUSTER)LED
MALFUNCTION INDICATOR PC74
OIL INDICATOR (BASE
CLUSTER)LED
OIL INDICATOR PC74
OVERHEAD CONSOLE
READINGPC579
OVERDRIVE OFF
INDICATORVFD*
READING 578
SEAT BELT INDICATOR LED
TEMPERATURE INDICATOR LED
TRAC OFF INDICATOR VFD*
TURN SIGNAL INDICATOR
(BASE CLUSTER)LED
TURN SIGNAL INDICATOR PC74
VISOR VANITY 6501966
VOLTAGE INDICATOR LED
* VACUUM
FLUORESCENT
DISPLAY
RSLAMPS/LIGHTING - INTERIOR8L-17
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OVERHEAD CONSOLE
TABLE OF CONTENTS
page page
OVERHEAD CONSOLE
DESCRIPTION............................2
OPERATION.............................3
DIAGNOSIS AND TESTING..................3
DIAGNOSIS & TESTING...................3
STANDARD PROCEDURE...................4
COURTESY LAMP REPLACEMENT..........4
COMPASS CALIBRATION..................4
COMPASS DEMAGNETIZING...............4
COMPASS VARIATION ADJUSTMENT........5
REMOVAL...............................6
INSTALLATION............................6
ELECTRONIC VEHICLE INFO CENTER
DESCRIPTION............................6
OPERATION.............................7
DIAGNOSIS AND TESTING..................7
TRAVELER MESSAGES...................7
STANDARD PROCEDURE...................8
EVIC PROGRAMMING....................8
REMOVAL...............................9
INSTALLATION............................9COMPASS/MINI-TRIP COMPUTER
DESCRIPTION............................9
OPERATION.............................10
DIAGNOSIS AND TESTING.................10
DIAGNOSIS AND TESTING...............10
REMOVAL..............................10
INSTALLATION...........................10
UNIVERSAL TRANSMITTER
DESCRIPTION...........................10
OPERATION.............................10
DIAGNOSIS AND TESTING.................11
UNIVERSAL GARAGE DOOR OPENER......11
AMBIENT TEMP SENSOR
DESCRIPTION...........................11
OPERATION.............................11
DIAGNOSIS AND TESTING.................11
AMBIENT TEMPERATURE SENSOR.........11
AMBIENT TEMPERATURE SENSOR
CIRCUIT..............................11
REMOVAL..............................12
INSTALLATION...........................12
OVERHEAD CONSOLE
DESCRIPTION
The available overhead consoles on RS models can
include the Electronic Vehicle Information Center
(EVIC), Compass Mini-Trip Computer (CMTC) or a
Compass Temperature Computer (CT). All consoles
are equipped with two reading/courtesy lamps and if
the vehicle is equipped with a power liftgate or
power sliding door(s) the overhead console will also
include command switches for these features. The
overhead console is mounted with one screw and two
snap clips to a molded plastic retainer bracket
located above the headliner.
DESCRIPTION - COMPASS
All the available overhead consoles on this model
include Compass information. While in the compass/
thermometer mode, the compass will display the
direction in which the vehicle is pointed using the
eight major compass headings (Examples: north is N,
northeast is NE). The self-calibrating compass unit
requires no adjusting in normal use. The only cali-
bration that may prove necessary is to drive the vehi-
cle in three complete circles at 5 to 8 kilometers-per-
hour (3 to 5 miles-per-hour), on level ground, in notless than forty-eight seconds. This will reorient the
compass unit to its vehicle.
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.DESCRIPTION - THERMOMETER
All the available overhead consoles on this model
include Temperature information. The thermometer
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 thermometer display several minutes
to respond to a major temperature change, such as
8M - 2 OVERHEAD CONSOLERS
ProCarManuals.com

driving out of a heated garage into winter tempera-
tures.
When the ignition switch is turned to the Off posi-
tion, the last displayed temperature reading stays in
the electronic control modules (CT, CMTC, EVIC)
memory. 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 read-
ing within five minutes.
The thermometer function is supported by an
ambient temperature sensor. The sensor is mounted
outside the passenger compartment near the front
and center of the vehicle, and is hard wired to the
Front Control Module (FCM). The FCM sends tem-
perature status messages to the module over the
J1850 PCI data bus circuit.
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 & TESTING - OVERHEAD
CONSOLE
If the problem with the overhead console is an
inaccurate or scrambled display, refer toSelf-Diag-
nostic Testlater in this group. If the problem with
the overhead console is incorrect Vacuum Fluorescent
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 Pro-
grammable Communications Interface (PCI) data bus
circuit. If the problem is a no-display condition, use
the following procedures. For complete circuit dia-
grams, refer toOverhead Consolein the Wiring
Diagrams section of the service manual.
(1) Check the fused B(+) fuse in the intelligent
power module. If OK, go to Step 2. If not OK, repair
the shorted circuit or component as required and
replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the intelligent power module. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit to the
fused B(+) fuse in the intelligent power module as
required.
(3) Check the fused ignition switch output (run/
start) fuse in the intelligent power module. If OK, go
to Step 4. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switchoutput (run/start) fuse in the intelligent power mod-
ule. If OK, go to Step 5. If not OK, repair the open
fused ignition switch output (run/start) circuit to the
ignition switch as required.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the overhead console. Check for continuity
between the ground circuit cavity of the roof wire
harness connector for the electronics module and a
good ground. There should be continuity. If OK, go to
Step 6. If not OK, repair the open ground circuit to
ground as required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
roof wire harness connector for the electronics mod-
ule. If OK, go to Step 7. If not OK, repair the open
fused B(+) circuit to the fused B(+) fuse in the intel-
ligent power module as required.
(7) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run/start) circuit cavity of the roof wire har-
ness connector for the electronics module. If OK,
refer toSelf-Diagnostic Testlater this group for
further diagnosis of the electronics module and the
J1850 PCI data bus circuit. If not OK, repair the
open fused ignition switch output (run/start) circuit
to the fuse in the intelligent power module as
required.
SELF-DIAGNOSTIC TEST
A self-diagnostic test is used to determine that the
electronics module is operating properly, and that all
the J1850 PCI data bus messages are being received
for initial operation. Initiate the self-diagnostic test
as follows:
(1) With the ignition switch in the Off position, on
Electronic Vehicle Information Center (EVIC) and
Compass Mini-Trip Computer (CMTC) equipped vehi-
cles simultaneously depress and hold theSTEP and
the RESET buttons. On Compass Temperature
Module (CT) equipped vehicles depress theC/T and
the US/M push buttons.
(2) Turn the ignition switch to the On position.
(3) Following completion of these tests, the elec-
tronics module will display one of the following mes-
sages:
²Pass Self Test (EVIC only), PASS (CT,
CMTC)- The electronics module is working properly.
²Failed Self Test (EVIC only), FAIL (CT,
CMTC)- The electronics module has an internal fail-
ure. The electronics module is faulty and must be
replaced.
²Failed J1850 Communication (EVIC only),
BUS (CT, CMTC)- The electronics module is not
receiving proper message input through the J1850
PCI data bus circuit. This can result from one or
RSOVERHEAD CONSOLE8M-3
OVERHEAD CONSOLE (Continued)
ProCarManuals.com

more faulty electronic modules in the vehicle, or from
a faulty PCI data bus. The use of a DRB IIItscan
tool and the proper Diagnostic Procedures manual
are required for further diagnosis.
NOTE: If the compass functions, but accuracy is
suspect, it may be necessary to perform a variation
adjustment. This procedure allows the compass
unit to accommodate variations in the earth's mag-
netic field strength, based on geographic location.
Refer to Compass Variation Adjustment in the Ser-
vice Procedures section of this group.
NOTE: If the compass reading displays dashes, and
only ªCALº appears in the display, demagnetizing
may be necessary to remove excessive residual
magnetic fields from the vehicle. Refer to Compass
Demagnetizing in the Service Procedures section of
this group.
STANDARD PROCEDURE - READING/
COURTESY LAMP REPLACEMENT
(1) Open hood, disconnect and isolate the negative
battery cable remote terminal from the remote bat-
tery post.
(2) Remove the reading/courtesy lamp lens. Using
a trim stick, gently pry the forward edge of the read-
ing/courtesy lamp lens outward.
(3) Remove the reading/courtesy lamp socket from
the overhead console. Rotate the reading/courtesy
lamp socket one quarter turn counter clockwise.
(4) Remove the lamp and socket assembly.
(5) Reverse the above procedure to install.
STANDARD PROCEDURE - COMPASS
CALIBRATION
CAUTION: Do not place any external magnets, such
as magnetic roof mount antennas, in the vicinity of
the compass. Do not use magnetic tools when ser-
vicing the overhead console.
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, CT) must have their compass calibrated
using this procedure. Do not attempt to calibrate the
compass near large metal objects such as other vehi-cles, 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.
Calibrate the compass manually as follows:
(1) Turn the ignition switch to the On position. If
the compass/thermometer data is not currently being
displayed, momentarily depress and release the C/T
push button to reach the compass/thermometer dis-
play.
(2) On Electronic Vehicle Information Center
(EVIC) and Compass Mini-Trip Computer (CMTC)
equipped vehicles depress the Reset push button and
hold the button down until ªCALº appears in the dis-
play. This takes about ten seconds, and appears
about five seconds after ªVAR = XXº is displayed. On
Compass Temperature Module (CT) equipped vehicles
depress the C/T push button and US/M push button
down until ªCALº appears in the display. This takes
about ten seconds, and appears about five seconds
after ªVAR = XXº is displayed.
(3) Release the push button(s).
(4) Drive the vehicle on a level surface, away from
large metal objects and power lines, through three or
more complete circles 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:
8M - 4 OVERHEAD CONSOLERS
OVERHEAD CONSOLE (Continued)
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