reset CHRYSLER CARAVAN 2003 User Guide

motors, and fuel pumps that have been found to be
potential sources of RFI or EMI.
OPERATION
There are two common strategies that can be used
to suppress Radio Frequency Interference (RFI) and
ElectroMagnetic Interference (EMI) radio noise. The
first suppression strategy involves preventing the
production of RFI and EMI electromagnetic signals
at their sources. The second suppression strategy
involves preventing the reception of RFI and EMI
electromagnetic signals by the audio system compo-
nents.
The use of braided ground straps in key locations
is part of the RFI and EMI prevention strategy.
These ground straps ensure adequate ground paths,
particularly for high current components such as
many of those found in the starting, charging, igni-
tion, engine control and transmission control sys-
tems. An insufficient ground path for any of these
high current components may result in radio noise
caused by induced voltages created as the high cur-
rent seeks alternative ground paths through compo-
nents or circuits intended for use by, or in close
proximity to the audio system components or circuits.
Preventing the reception of RFI and EMI is accom-
plished by ensuring that the audio system compo-
nents are correctly installed in the vehicle. Loose,
corroded or improperly soldered wire harness connec-
tions, improperly routed wiring and inadequate audio
system component grounding can all contribute to
the reception of RFI and EMI. A properly grounded
antenna body and radio chassis, as well as a shielded
antenna coaxial cable with clean and tight connec-
tions will each help reduce the potential for reception
of RFI and EMI.
REMOTE SWITCHES
DESCRIPTION
A remote radio control switch option is available on
some models. Two rocker-type switches are mounted
on the back (instrument panel side) of the steering
wheel spokes (Fig. 12). The switch on the left spoke
is the seek switch and has seek up, seek down, and
preset station advance functions. The switch on the
right spoke is the volume control switch and has vol-
ume up, and volume down functions. The switch on
the right spoke also includes a ªmodeº control that
allows the driver to sequentially select AM radio, FM
radio, cassette player, CD player or CD changer (if
equipped).
OPERATION
These switches are resistor multiplexed units that
are hard-wired to the Body Control Module (BCM)
through the clockspring. The BCM sends the proper
messages on the Programmable Communications
Interface (PCI) data bus network to the radio
receiver. For diagnosis of the BCM or the PCI data
bus, the use of a DRB IIItscan tool and the proper
Diagnostic Procedures manual are recommended. For
more information on the operation of the remote
radio switch controls, refer to the owner's manual in
the vehicle glove box.
DIAGNOSIS AND TESTING - REMOTE
SWITCHES
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
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. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
Fig. 12 Remote Radio Switch Operational View
1 - PRESET SEEK
2 - SEEK UP
3 - VOLUME UP
4 - MODE
5 - VOLUME DOWN
6 - SEEK DOWN
8A - 12 AUDIORS
RADIO NOISE SUPPRESSION COMPONENTS (Continued)
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read and/or reset the Pinion Factor, it is necessary to
use a DRBIIItscan tool.
(1) Plug the DRBIIItscan tool into the diagnostic
connector located under the instrument panel.
(2) Select the Transmission menu.
(3) Select the Miscellaneous menu.
(4) Select Pinion Factor. Then follow the instruc-
tions on the DRBIIItscan tool screen.
STANDARD PROCEDURE - QUICK LEARN
PROCEDURE
The quick learn procedure requires the use of the
DRBIIItscan tool. This program allows the PCM/
TCM to recalibrate itself. This will provide the best
possible transaxle operation.
NOTE: The quick learn procedure should be per-
formed if any of the following procedures are per-
formed:
²Transaxle Assembly Replacement
²Powertrain/Transmission Control Module
Replacement
²Solenoid/Pressure Switch Assembly Replacement
²Clutch Plate and/or Seal Replacement
²Valve Body Replacement or Recondition
To perform the Quick Learn Procedure, the follow-
ing conditions must be met:
²The brakes must be applied
²The engine speed must be above 500 rpm
²The throttle angle (TPS) must be less than 3
degrees
²The shift lever position must stay until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the
DRBIIItindicates the procedure is complete
²The calculated oil temperature must be above
60É and below 200É
(1) Plug the DRBIIItscan tool into the diagnostic
connector. The connector is located under the instru-
ment panel.
(2) Go to the Transmission screen.
(3) Go to the Miscellaneous screen.
(4) Select Quick Learn Procedure. Follow the
instructions of the DRBIIItto perform the Quick
Learn Procedure.
REMOVAL
REMOVAL - SBEC CONTROLLER
(1) Disconnect the negative battery cable.
(2) Remove the battery shield, refer to the Battery
section for more information.
(3) Remove the 2 upper PCM bracket bolts (Fig.
11).(4) Remove the 2 PCM connectors.
(5) Remove the headlamp, refer to the Lamps sec-
tion for more information.
(6) Remove the lower PCM mounting bolt (Fig. 12).
(7) Remove PCM.
Fig. 11 PCM
1 - Attaching Bolts
Fig. 12 PCM LOWER BOLT
8E - 16 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)
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STANDARD PROCEDURE
STANDARD PROCEDURE - PINION FACTOR
SETTING
NOTE: This procedure must be performed if the
PCM/TCM has been replaced with a NEW or
replacement unit. Failure to perform this procedure
will result in an inoperative or improperly calibrated
speedometer.
The vehicle speed readings for the speedometer are
taken from the output speed sensor. The PCM/TCM
must be calibrated to the different combinations of
equipment (final drive and tires) available. Pinion
Factor allows the technician to set the Powertrain/
Transmission Control Module initial setting so that
the speedometer readings will be correct. To properly
read and/or reset the Pinion Factor, it is necessary to
use a DRBIIItscan tool.
(1) Plug the DRBIIItscan tool into the diagnostic
connector located under the instrument panel.
(2) Select the Transmission menu.
(3) Select the Miscellaneous menu.
(4) Select Pinion Factor. Then follow the instruc-
tions on the DRBIIItscan tool screen.
STANDARD PROCEDURE - QUICK LEARN
PROCEDURE
The quick learn procedure requires the use of the
DRBIIItscan tool. This program allows the PCM/
TCM to recalibrate itself. This will provide the best
possible transaxle operation.
NOTE: The quick learn procedure should be per-
formed if any of the following procedures are per-
formed:
²Transaxle Assembly Replacement
²Powertrain/Transmission Control Module
Replacement
²Solenoid/Pressure Switch Assembly Replacement
²Clutch Plate and/or Seal Replacement
²Valve Body Replacement or Recondition
To perform the Quick Learn Procedure, the follow-
ing conditions must be met:
²The brakes must be applied
²The engine speed must be above 500 rpm
²The throttle angle (TPS) must be less than 3
degrees
²The shift lever position must stay until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the
DRBIIItindicates the procedure is complete²The calculated oil temperature must be above
60É and below 200É
(1) Plug the DRBIIItscan tool into the diagnostic
connector. The connector is located under the instru-
ment panel.
(2) Go to the Transmission screen.
(3) Go to the Miscellaneous screen.
(4) Select Quick Learn Procedure. Follow the
instructions of the DRBIIItto perform the Quick
Learn Procedure.
REMOVAL
NOTE: If transmission control module is being
replaced with a new or replacement unit, the Pinion
Factor and Quick Learn procedures must be per-
formed. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE) (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MODULES/
TRANSMISSION CONTROL MODULE - STANDARD
PROCEDURE)
(1) Disconnect battery negative cable.
(2) Raise vehicle on hoist.
(3) Remove left front tire/wheel assembly.
(4) Pull back splash shield to gain access to TCM
location.
(5) Disconnect TCM 60-way connector (Fig. 18).
(6) Remove three (3) TCM-to-rail screws and
remove TCM from vehicle (Fig. 19).
Fig. 18 Transmission Control Module 60-way
Connector
1 - TRANSMISSION CONTROL MODULE (TCM)
2 - 60-WAY CONNECTOR
RSELECTRONIC CONTROL MODULES8E-23
TRANSMISSION CONTROL MODULE (Continued)
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INSTALLATION
NOTE: If transmission control module is being
replaced with a new or replacement unit, the Pinion
Factor and Quick Learn procedures must be per-
formed. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE) (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MODULES/
TRANSMISSION CONTROL MODULE - STANDARD
PROCEDURE)
(1) Install TCM into position (Fig. 20). Install
three (3) screws and torque to 3 N´m (30 in. lbs.).
(2) Install TCM harness 60±way connector (Fig.
21) and torque to 4 N´m (35 in. lbs.).
(3) Install splash shield into position with fasten-
ers.
(4) Install left front wheel/tire assembly.
(5) Lower vehicle.
(6) Connect battery negative cable.
(7) If TCM was replaced, reset Pinion Factor and
Quick Learn. (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/TRANSMISSION
CONTROL MODULE - STANDARD PROCEDURE)(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE).
Fig. 19 Transmission Control Module Removal/
Installation
1 - SCREW
2 - TRANSMISSION CONTROL MODULE (TCM)
3 - CLIP
4 - LEFT RAIL
Fig. 20 Transmission Control Module Removal/
Installation
1 - SCREW
2 - TRANSMISSION CONTROL MODULE (TCM)
3 - CLIP
4 - LEFT RAIL
Fig. 21 Transmission Control Module 60-way
Connector
1 - TRANSMISSION CONTROL MODULE (TCM)
2 - 60-WAY CONNECTOR
8E - 24 ELECTRONIC CONTROL MODULESRS
TRANSMISSION CONTROL MODULE (Continued)
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KNOCK SENSOR
DESCRIPTION
The knock sensor threads into the cylinder block.
The knock sensor is designed to detect engine vibra-
tion that is caused by detonation.
OPERATION
When the knock sensor detects a knock in one of
the cylinders, it sends an input signal to the PCM. In
response, the PCM retards ignition timing for all cyl-
inders by a scheduled amount.
Knock sensors contain a piezoelectric material
which constantly vibrates and sends an input voltage
(signal) to the PCM while the engine operates. As the
intensity of the crystal's vibration increases, the
knock sensor output voltage also increases.
The voltage signal produced by the knock sensor
increases with the amplitude of vibration. The PCM
receives as an input the knock sensor voltage signal.
If the signal rises above a predetermined level, the
PCM will store that value in memory and retard
ignition timing to reduce engine knock. If the knock
sensor voltage exceeds a preset value, the PCM
retards ignition timing for all cylinders. It is not a
selective cylinder retard.
The PCM ignores knock sensor input during engine
idle conditions. Once the engine speed exceeds a
specified value, knock retard is allowed.
Knock retard uses its own short term and long
term memory program.
Long term memory stores previous detonation
information in its battery-backed RAM. The maxi-
mum authority that long term memory has over tim-
ing retard can be calibrated.
Short term memory is allowed to retard timing up
to a preset amount under all operating conditions (as
long as rpm is above the minimum rpm) except WOT.
The PCM, using short term memory, can respond
quickly to retard timing when engine knock is
detected. Short term memory is lost any time the
ignition key is turned off.
NOTE: Over or under tightening affects knock sen-
sor performance, possibly causing improper spark
control.
REMOVAL
REMOVAL - 2.4L
The knock sensor threads into the side of the cyl-
inder block in front of the starter (Fig. 12).
(1) Disconnect electrical connector from knock sen-
sor.(2) Use a crow foot socket to remove the knock
sensors.
REMOVAL - 3.8L
The knock sensor threads into the side of the cyl-
inder block in the rear.
(1) Disconnect the negative battery cable.
(2) Raise vehicle and support.
(3) On All Wheel Drive vehicles remove the PTU
(Power Transfer Unit), refer to the Transmission sec-
tion for more information.
(4) Disconnect electrical connector from knock sen-
sor.
(5) Use a crow foot socket to remove the knock
sensor.
INSTALLATION
INSTALLATION - 2.4L
The knock sensor threads into the side of the cyl-
inder block in front of the starter (Fig. 12).
(1) Install knock sensor. Tighten knock sensor to
10 N´m (7 ft. lbs.) torque.Over or under tighten-
ing effects knock sensor performance, possibly
causing improper spark control.
(2) Attach electrical connector to knock sensor.
Fig. 12 Knock Sensor
1 - GENERATOR
2 - INTAKE MANIFOLD
3 - KNOCK SENSOR
4-STARTER
8I - 8 IGNITION CONTROLRS
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DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - SELF-DIAGNOSTICS
The instrument clusters are equipped with a self
diagnostic test feature to help identify electronic prob-
lems. Prior to any test, perform the Self-Diagnostic
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 running, 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 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 odometer dis-
play. Refer to the INSTRUMENT CLUSTER DTC'S
table to determine what each trouble code means.
INSTRUMENT CLUSTER DTC'S
DTC DESCRIPTION
100.0 LOOP-BACK FAILURE
100.1 ABS COMMUNICATION FAULT
100.2 BCM COMMUNICATION FAULT
100.3 EATX COMMUNICATION FAULT
100.4 FCM COMMUNICATION FAULT
100.5 ORC COMMUNICATION FAULT
100.6SBEC/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
400.0 EEPROM READ/WRITE FAILURE
400.1IMPROPER POWER DOWN
DETECTED
CALIBRATION TEST
The CLUSTER CALIBRATION 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
If a segment in the odometer does not illuminate
normally, a problem exists in the display.
ELECTRONIC TRANSMISSION RANGE INDICATOR
SEGMENT TEST
If a segment in the transmission range indicator
does not illuminate normally, a problem exists in the
display.
DIAGNOSIS AND TESTING - CLUSTER
DIAGNOSIS
CONDITIONS
Refer to the following tables for possible problems,
causes, and corrections.
²INSTRUMENT CLUSTER DIAGNOSIS
²SPEEDOMETER DIAGNOSIS
²TACHOMETER DIAGNOSIS
²FUEL GAUGE DIAGNOSIS
²TEMPERATURE GAUGE DIAGNOSIS
²ODOMETER DIAGNOSIS
²ELECTRONIC GEAR INDICATOR DISPLAY
DIAGNOSIS
NOTE: Always check the functionality of the cluster
by running the self test prior to troubleshooting.
8J - 2 INSTRUMENT CLUSTERRS
INSTRUMENT CLUSTER (Continued)
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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. 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.
2. 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.TRIP SWITCH DOESN'T
WORK.IF CLUSTER WILL NOT GO INTO SELF DIAGNOSTIC
MODE AND CANNOT TOGGLE BETWEEN
ODOMETER AND TRIP ODOMETER, REPLACE
CLUSTER.
TRIP ODOMETER WON'T
RESET.RESET SWITCH
DOESN'T WORK.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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HEADLAMP
SWITCH
POSITION13-WAY
CONNECTOR
TERMINALRESISTANCE
HEADLAMP
LEVELING
SWITCH
POSITION13-WAY
CONNECTOR
TERMINALRESISTANCE
01 TO 7 3238 - 3456V
1 TO 2 3181 - 3400V
1 1 TO 7 1195 - 1225V
2 1 TO 7 746 - 765V
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Instrument Panel Lower Steering
Column Cover. Refer to Body, Instrument Panel,
Lower Steering Column Cover, Removal.
(3) Reach up behind the left side of the instrument
panel and depress spring clip on top or bottom of
headlamp switch. Firmly push out on the headlamp
switch assembly.
(4) Disconnect the wiring connectors.
(5) Remove switch from vehicle.
INSTALLATION
(1) Connect the wiring connectors.
(2) Place headlamp switch assembly into position
and firmly snap into place.
(3) Install the Instrument Panel Lower Steering
Column Cover. Refer to Body, Instrument Panel,
Lower Steering Column Cover, Installation.
(4) Connect the battery negative cable.
HEADLAMP UNIT
STANDARD PROCEDURE
STANDARD PROCEDURE - HEADLAMP UNIT
ALIGNMENT
HEADLAMP UNIT ALIGNMENT PREPARATION
(1) Verify headlamp dimmer switch and high beam
indicator operation.
(2) Inspect and correct damaged or defective com-
ponents that could interfere with proper headlamp
alignment.
(3) Verify proper tire inflation.
(4) Clean headlamp lenses.
(5) Verify that luggage area is loaded as the vehi-
cle is routinely used.(6) Vehicles equipped with automatic load leveling
suspension should be driven normally for approxi-
mately 5 km (3 miles) before attempting a proper
headlamp unit alignment.
(7) Fuel tank should be FULL. Add 2.94 kg (6.5
lbs.) of weight over the fuel tank for each estimated
gallon of missing fuel.
ALIGNMENT SCREEN PREPARATION
(1) Position vehicle on a level surface perpendicu-
lar to a flat wall 7.62 meters (25 ft.) away from front
of headlamp lens (Fig. 19).
(2) If necessary, tape a line on the floor 7.62
meters (25 ft.) away from and parallel to the wall.
(3) Rock vehicle side-to-side three times and allow
suspension to stabilize.
(4) Jounce front suspension three times by pushing
downward on front bumper and releasing.
(5) Measure the distance from the center of head-
lamp lens to the floor. Transfer measurement to the
alignment screen (with tape). Use this line for
up/down adjustment reference.
HEADLAMP UNIT ADJUSTMENT
The low beam headlamp will project on the screen
upper edge of the beam (cut-off) at the horizontal
lamp centerline   50 mm (2 in.). Horizontal aim is
preset and can not be adjusted. The high beam pat-
tern should be correct when the low beams are
aligned properly (Fig. 20). To adjust headlamp verti-
cal alignment, rotate adjustment screw to achieve the
specified low beam cut-off location.
STANDARD PROCEDURE - HEADLAMP UNIT
ALIGNMENT - EXPORT
HEADLAMP UNIT ALIGNMENT PREPARATION
(1) Verify that the headlamp leveling switch is in
the ª0º position.
(2) Inspect and correct damaged or defective com-
ponents that could interfere with proper headlamp
alignment.
(3) Verify proper tire inflation.
(4) Clean headlamp lenses.
(5) Verify that luggage area is loaded as the vehi-
cle is routinely used.
(6) Vehicles equipped with automatic load leveling
suspension should be driven normally for approxi-
mately 5 km (3 miles) before attempting a proper
headlamp unit alignment.
(7) Fuel tank should be FULL. Add 2.94 kg (6.5
lbs.) of weight over the fuel tank for each estimated
gallon of missing fuel.
RSLAMPS/LIGHTING - EXTERIOR8L-17
HEADLAMP SWITCH (Continued)
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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 - TEMPERATURE
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 (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 temperature function is supported by an ambi-
ent temperature sensor. The 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.
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-Diag-
nostic Testbelow. 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 Con-
trol Module (FCM) over the J1850 Programmable
Communications Interface (PCI) data bus circuit. If
the problem is a no-display condition, use the follow-
ing procedures. For complete circuit diagrams, refer
toOverhead Consolein the Wiring Diagrams sec-
tion of the service manual.(1) Check the fused B(+) fuse in the integrated
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 integrated power module. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit to the
fused B(+) fuse in the integrated power module as
required.
(3) Check the fused ignition switch output (run/
start) fuse in the integrated 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 switch
output (run/start) fuse in the integrated 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 inte-
grated 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 Test
later 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 integrated 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.
8M - 2 MESSAGE SYSTEMSRS
OVERHEAD CONSOLE (Continued)
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(2) Turn the ignition switch to the On position.
(3)
Following completion of these tests, the electron-
ics module will display one of the following messages:
a.Pass Self Test (EVIC only), PASS (CT,
CMTC)- The electronics module is working properly.
b.Failed Self Test (EVIC only), FAIL (CT,
CMTC)- The electronics module has an internal fail-
ure. The electronics module is faulty and must be
replaced.
c.Failed 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
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 Stan-
dard 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 Standard Procedures section
of this group.
STANDARD PROCEDURE
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 - MODULE LAMP
REPLACEMENT
(1) Remove the overhead console (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - REMOVAL).
(2) Using a flat blade screwdriver twist out socket/
lamp (Fig. 1).(3) Replace lamp(s) as necessary.
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.
Fig. 1 EVIC
1 - OVERHEAD CONSOLE HOUSING
2 - EVIC/CMTC MODULE
3 - ILLUMINATION LAMPS
4 - MODULE RETAINING SCREWS
RSMESSAGE SYSTEMS8M-3
OVERHEAD CONSOLE (Continued)
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