transfer DODGE RAM 1500 1998 2.G Repair Manual

TRANSFER CASE CONTROL
MODULE
DESCRIPTION
The Transfer Case Control Module (TCCM) (Fig. 8)
is a microprocessor-based assembly, controlling the
4X4 transfer case shift functions via the actuation of
a shift motor and utilizing the feedback of a mode
sensor assembly. Communication is via the PCI serial
bus. Inputs include user selectable 4X4 modes that
include 2WD, AWD, 4HI, 4LO, and Neutral. The logic
and driver circuitry is contained in a molded plastic
housing with an embedded heat-sink and is located
behind the left side of the lower instrument panel.
OPERATION
The Transfer Case Control Module (TCCM) utilizes
the input from the transfer case mounted mode sen-
sor, the instrument panel mounted selector switch,
and the following information from the vehicle's PCI
serial bus to determine if a shift is allowed.
²Engine RPM and Vehicle Speed
²Diagnostic Requests
²Manual Transmission and Brake Applied
²PRNDL
²Ignition Status
²ABS Messages
Once the TCCM determines that a requested shift
is allowed, it actuates the bi-directional shift motor
as necessary to achieve the desired transfer case
operating mode. The TCCM also monitors the mode
sensor while controlling the shift motor to determine
the status of the shift attempt.Several items can cause the requested shift not to
be completed. If the TCCM has recognized a fault
(DTC) of some variety, it will begin operation in one
of four Functionality Levels. These levels are:
²Level Zero- Normal Operation.
²Level One- Only Mode Shifts Are Allowed.
²Level Two- Only Mode Shifts and Shifts Into
LOW Are Allowed (No Neutral Shifts Are Allowed).
²Level Three- No Shifts Are Allowed
The TCCM can also be operating in one of three
possible power modes. These power modes are:
²Full Power Modeis the normal operational
mode of the module. This mode is achieved by normal
PCI bus traffic being present and the ignition being
in the RUN position.
²Reduced Power Modewill be entered when
the ignition has been powered off. In this state, the
module will shut down power supplied to external
devices, and to electronic interface inputs and out-
puts. From this state the module can enter either
Sleep Mode or Full Power Mode. To enter this mode,
the module must receive an ignition message denot-
ing that the ignition is off, or not receive any mes-
sages for 5  0.5 seconds. To exit this mode, the
module must receive one ignition message that
denotes that the ignition is in the RUN position.
²Sleep Modewill be entered, from the Reduced
Power Mode, when no PCI traffic has been sensed for
20  1 seconds. If during Sleep Mode the module
detects PCI bus traffic, it will revert to the Reduced
Power mode while monitoring for ignition messages.
It will remain in this state as long as there is traffic
other than run or start messages, and will return to
Sleep mode if the bus goes without traffic for 20  1
seconds.
SHIFT REQUIREMENTS
If the TCCM is in full power mode and at function-
ality level zero, it uses the following criteria to deter-
mine if a shift is allowed.
If any of the driver controllable conditions are not
met once the shift request is recognized, the TCCM
will solidly illuminate the source position's LED and
flash the desired position's LED for all shifts except
NEUTRAL. The NEUTRAL shift LED strategy will
be discussed later.
Mode shiftswill be allowed regardless of trans-
mission gear or vehicle speed, whenever the following
conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²A change in the Selector switch state indicates
that a mode shift has been requested.
²A valid mode sensor signal is being sensed by
the TCCM.
Fig. 8 Transfer Case Control Module (TCCM)
Location
1 - INSTRUMENT PANEL
2 - TRANSFER CASE CONTROL MODULE (TCCM)
3 - TRANSFER CASE SELECTOR SWITCH
8E - 16 ELECTRONIC CONTROL MODULESDR

²Proper transmit/receive messages are occurring
on the PCI bus.
²Ignition key switch is in the RUN position.
Range shiftswill be allowed only if all of the fol-
lowing conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²A change in the Selector Switch state indicating
a range shift has been requested.
²Transmission in NEUTRAL signal must be rec-
ognized for at least 1.5 seconds  100 msec. (Auto-
matic transmissions only)
²Proper transmit/receive messages are occurring
on the PCI bus.
²Clutch signal is recognized for 500 msec   50
msec (Manual transmissions only).
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).
²Ignition key switch is in the RUN position.
²A valid mode sensor signal is being sensed by
the TCCM.
Ashift into transfer case Neutralwill be
allowed only if all of the following conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²The recessed Neutral Selection switch has been
depressed continuously for 4.0 seconds  100 msec
while all shift conditions have been continuously met.
²Transmission in NEUTRAL signal recognized
from the bus. (Automatic transmissions only)
²Clutch signal is recognized from the bus (Man-
ual transmissions only).
²Proper message transmissions/receptions are
occurring on the PCI bus.
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).
²Ignition key switch is in the RUN position,
engine off.
²Foot Brake is applied.
²A valid mode sensor signal is being sensed by
the TCCM.
Ashift out of transfer case Neutralwill be
allowed only if all of the following conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²The recessed Neutral Selection switch has been
depressed continuously for 1.0 seconds  100 msec
while all shift conditions have been continuously met.
²Transmission in NEUTRAL signal recognized
from the bus.(Automatic transmissions only)
²Clutch signal is recognized from the bus (Man-
ual transmissions only).
²Proper message transmissions/receptions are
occurring on the PCI bus.
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).²Ignition key switch is in the RUN position.
²Foot Brake is applied.
²A valid mode sensor signal is being sensed by
the TCCM.
SHIFT SEQUENCES
Once all the driver controllable conditions for the
requested shift have been met, the TCCM begins a
shift timer with a maximum duration of 1 second per
'D' channel transition. If the shift timer expires
before the TCCM recognizes to correct mode sensor
code, the shift is considered to have been blocked.
The blocked shift will increment the blocked shift
counter by one. The TCCM strategy for handling
blocked shifts will be described later. The process the
TCCM performs for the various shifts will be
described first.
RANGE AND MODE SHIFTS
The process for performing all the range and mode
shifts are the same. The following steps describe the
process.
²Allow time for Selector Switch debounce; 250
msec  50 msec.
²Extinguish the source gear's LED while flashing
desired transfer case position's LED.
²Engage the shift motor for a maximum of 1 sec-
ond  100 msec per 'D' channel transition in the des-
tination gear's direction while monitoring the mode
sensor channel transitions.
²Disengage the shift motor when the correct
mode sensor code is recognized.
²Solidly illuminate the selected gear's LED.
²Transmit a bus message that the transfer case
shift is complete.
²If the desired mode sensor code is not received
after the shift timer expires (ie. a blocked or other
condition exists), stop driving the motor and wait for
200 msec  50 msec. The shift motor is then reversed
in the direction back toward the source gear for up to
1.0 seconds  100 msec. per 'D' channel. The TCCM
waits for 2.0 seconds  50 msec. and repeats the
attempt to shift to the desired position.
The exception to the preceding sequence is when a
shift from 4L to 2WD/AWD is requested. If 2WD/
AWD is requested from the 4L position, the transfer
case is first driven to the 4H position. If the 4H posi-
tion is reached, the transfer case is then driven back
to the 2WD/AWD position and the shift is considered
complete. If the transfer case does not reach any the
4H position, but is in the 2WD/AWD 'D' channel, or
the 2WD/AWD between gear position on the 4H side
of 2WD/AWD, the shift is also considered complete.
DRELECTRONIC CONTROL MODULES 8E - 17
TRANSFER CASE CONTROL MODULE (Continued)

SHIFT OUT OF NEUTRAL
The following steps describe the process for a shift
out of NEUTRAL.
²Extinguish the Neutral LED.
²Engage the shift motor for a maximum of 1 sec-
ond  100 msec toward the transfer case 4H mode
position while monitoring the mode sensor channel
transitions.
²Disengage the shift motor when the correct
mode sensor code is recognized.
²Extinguish the Neutral LED.
²Transmit a bus message that the transfer case
shift is complete.
²If the desired mode sensor code is not received
after the shift timer expires (ie. a blocked or other
condition exists), stop driving the motor and wait for
200 msec  50 msec. The shift motor is then reversed
in the direction back toward the source gear for up to
1.0 seconds 100 msec. The TCCM waits for 2.0 sec-
onds  50 msec. and repeats the attempt to shift to
the desired position.
²When the Neutral button is released, if the 4H
position is the desired position, the shift is complete.
Illuminate the 4H LED.
²Otherwise when the Neutral button is released,
if all of the shift requirements are being met then
engage the shift motor towards the desired position
for 1 second  100 msec per 'D' channel. (if require-
ments for shifting are not met, illuminate the 4H
LED and flash the destination LED as an indication
to the driver that all of the driver controllable shift
conditions are not being met). If this requires
another range or mode shift, begin the range/mode
shift process.
²If the desired mode sensor code is not received
after the shift timer expires (i.e. a blocked or other
condition exists), refer to the section on Blocked Shift
Strategy.
BLOCKED SHIFT STRATEGY
When a shift is commanded, the shift motor will be
driven towards its destination position, except in the
case of shifting out of Neutral if 4L was selected (the
transfer case will shift to the 4H position first, before
proceeding to 4L). If the shift is blocked on the way
to the destination, the TCCM may attempt to drivethe motor back to the original position. This process
will be allowed to occur 5 times. If the transfer case
has reached a non-NEUTRAL 'D' channel during the
shift re-attempts, the LED for the achieved gear posi-
tion is illuminated and the shift attempts are
stopped. To re-attempt the desired shift, the selector
switch will need to be rotated to the current position
until the switch debounce timer expires then a shift
will need to be requested again.
At the end of the 5th blocked attempt, the shift
motor is driven towards the last known 'D' channel
position. If this motor drive allows the transfer case
to reach the 2WD/AWD 'D' channel, or the 2WD/AWD
between gear position on the 4H side of 2WD/AWD,
the shift is considered complete and the shift
attempts are ended.
If the mode sensor is in the NEUTRAL region at
the expiration of the shift timer, the TCCM will con-
tinue to make the shift attempts according to the
blocked shift strategy independent of whether or not
the driver controlled conditions are met.
For shifts from NEUTRAL, if all 5 attempts fail to
reach the desired position (which by default is 4H),
the motor will be driven to stall in the direction of
4H or 4L, depending on the achieved position. If the
transfer case has reached the 2WD/AWD or 4L
between gear position nearest the NEUTRAL posi-
tions and the shift conditions are no longer being
met, the transfer case will be driven toward the cor-
responding 'D' channel. Otherwise, the transfer case
will be driven in the direction opposite the last
attempt with the desired target being 4H or 4L.
If the transfer case reaches the 2WD/AWD 'D'
channel when being driven in the 4H direction, then
one final 1.0 second drive toward 4H is attempted. If
the transfer case then reaches any of the 4H posi-
tions, the shift is considered complete and the 4H
LED is illuminated. If the transfer case is still the
2WD/AWD position, the shift is considered complete
and the 2WD/AWD LED is illuminated.
NOTE: If after the 5th blocked shift and reversal
attempt, if the transfer case position is in the NEU-
TRAL region, shift attempts will continue until a
non-NEUTRAL 'D' channel is reached.
8E - 18 ELECTRONIC CONTROL MODULESDR
TRANSFER CASE CONTROL MODULE (Continued)

SHIFT REVERSAL TARGETS
If the shift timer expires (1 second per 'D' channel)
and the transfer case has not reached the desired
position, all shifts will attempt to return to their
original position with the exceptions of:
²If the intended shift is going to the High rail
from Low and can't make it, but it can make the
2WD/AWD position, the motor stops at that position.
The TCCM will not attempt to cross back over NEU-
TRAL if it does not have to. This means that there
was a block on the first attempt to go to 4H and the
transfer case has made it through NEUTRAL to a
known good position, then the motor will go back
only to the 2WD/4WD position and execute the
remainder of the attempts from there.
²For shifts out of NEUTRAL, any time a shift is
commanded out of NEUTRAL, the system needs to
get out. The TCCM should never go to NEUTRAL
unless the driver is commanding it and all required
conditions are being met
ENCODER DRIFT CORRECTION
Whenever a shift is completed, the TCCM stores
the position in memory as the transfer case's
intended position. The TCCM continuously monitors
the mode sensor and if the mode sensor drifts toward
into a NEUTRAL region sensor position for 2.0 sec-
onds, the TCCM will perform a motor drive to correct
the drift. The transfer case will be driven toward the
intended position for 1.0 seconds 100 msec. The
TCCM will wait for 2.0 seconds  50 msec. and repeat
the attempt to shift to the desired position. This will
continue until the intended position is reached.
SHIFT MOTOR BRAKING
Two modes of shift motor braking are employed to
improve shift performance, static and dynamic. Static
shift motor braking is utilized under the following
conditions:
²Whenever the transfer case is in the 2WD/AWD
or 4L 'D' channel position.²Whenever an invalid mode sensor code is
present.
Static motor braking is achieved by applying +12V
on both shift motor wires.
NOTE: Static Shift Motor Braking is independent of
ignition key position.
SHIFT ATTEMPT LIMIT
To protect the transfer case system, the TCCM will
impose a limit on the number of shifts that can occur
over a calibrated time period. The system will moni-
tor the number of 'D' channel segment transitions
that occur in any 30 second time period. If the num-
ber of segment transitions is 30 or greater, the sys-
tem will go into a default mode. The default mode of
operation for shifting is that the number of allowed
'D' channel transitions permitted to occur will be 3
over each 15 second  100 msec calibrated window of
time. After 5 minutes  100 msec, the motor can be
assumed to have cooled down and the system will
revert to normal operation. The following rules also
apply to the shift limit:
²The attempt limit will not prevent shifts coming
out of NEUTRAL, they will be allowed regardless of
the counter/timer.
²Any shift that is in progress when the counter
reaches a maximum count in time will be allowed to
complete before the default mode is entered. D-chan-
nel transitions during this period will not be counted
towards the default mode limit.
²A block, regardless of the direction, whether
towards destination or back towards reversal target
(shift timer expiring), will count as a value of 2 tran-
sitions towards the 30 segment transitions to go into
default mode as defined above. Current attempt limit
values are 30 transitions in 30 seconds and default
mode values are 3 transitions every 15 seconds for 5
minutes.
DRELECTRONIC CONTROL MODULES 8E - 19
TRANSFER CASE CONTROL MODULE (Continued)

(4) Install ignition coil(s). Refer to Ignition Coil
Removal/Installation.
5.7L V-8
(1) Special care should be taken when installing
spark plugs into the cylinder head spark plug wells.
Be sure the plugs do not drop into the plug wells as
electrodes can be damaged.
(2) Start the spark plug into cylinder head by
hand to avoid cross threading aluminum threads. To
aid in installation, attach a piece of rubber hose, or
an old spark plug boot to spark plug.
(3) The 5.7L V-8 is equipped with torque critical
design spark plugs. Do not exceed 15 ft. lbs. torque.
Tighten spark plugs. Refer to torque specifications.
(4) Before installing spark plug cables to either the
spark plugs or coils, apply dielectric grease to inside
of boots.
(5) To prevent ignition crossfire, spark plug cables
MUSTbe placed in cable tray (routing loom) into
their original position. Refer to Spark Plug Cable
Removal for a graphic.
(6) Install ignition coil(s) to necessary spark plugs.
Refer to Ignition Coil Installation.
(7) Install spark plug cables to remaining spark
plugs. Remember to apply dielectric grease to inside
of boots.
IGNITION COIL CAPACITOR
DESCRIPTION
One coil capacitor is used. It is located in the right-
rear section of the engine compartment.
OPERATION
The coil capacitor(s) help dampen the amount of
conducted electrical noise to the camshaft position
sensor, crankshaft position sensor, and throttle posi-
tion sensor. This noise is generated on the 12V sup-
ply wire to the ignition coils and fuel injectors.
REMOVAL
The coil capacitor is located in the right-rear sec-
tion of the engine compartment. It is attached with a
mounting stud and nut.
(1) Disconnect electrical connector at capacitor
(Fig. 31).
(2) Remove mounting nut and remove ground
strap.
(3) Remove capacitor.
INSTALLATION
(1) Position capacitor to mounting stud.
(2) Position ground strap to mounting stud.
(3) Tighten nut to 7 N´m (60 in. lbs.) torque.
(4) Connect electrical connector to coil capacitor.
SPARK PLUG CABLE
DESCRIPTION
Spark plug cables are sometimes referred to as sec-
ondary ignition wires, or secondary ignition cables.
Plug cables are used only on the 5.7L V-8 engine.
OPERATION
The spark plug cables transfer electrical current
from the ignition coil(s) and/or distributor, to individ-
ual spark plugs at each cylinder. The resistive spark
plug cables are of nonmetallic construction. The
cables provide suppression of radio frequency emis-
sions from the ignition system.
Plug cables are used only on the 5.7L V-8 engine.
Fig. 31 CAPACITOR LOCATION
1 - COIL CAPACITOR
2 - MOUNTING STUD
3 - GROUND STRAP
4 - MOUNTING NUT
5 - ELEC. CONNECT.
DRIGNITION CONTROL 8I - 21
SPARK PLUG (Continued)

INPUT AND OUTPUT CIRCUITS
HARD WIRED INPUTS
The hard wired inputs to the EMIC include the fol-
lowing:
²Brake Lamp Switch Output
²Driver Cylinder Lock Switch Sense
²Driver Door Ajar Switch Sense
²Driver Door Lock Switch MUX - with
Power Locks
²Fused B(+) - Ignition-Off Draw
²Fused B(+) - Power Lock Feed - with Power
Locks
²Fused Ignition Switch Output (Accessory-
Run)
²Fused Ignition Switch Output (Off-Run-
Start)
²Fused Ignition Switch Output (Run-Start)
²Headlamp Dimmer Switch MUX
²Headlamp Switch MUX
²Horn Relay Control
²Key-In Ignition Switch Sense
²Left Rear Door Ajar Switch Sense
²Panel Lamps Dimmer Switch Signal
²Park Brake Switch Sense
²Passenger Door Ajar Switch Sense
²Passenger Door Lock Switch MUX - with
Power Locks
²Radio Control MUX
²Right Rear Door Ajar Switch Sense
²RKE Supply - with RKE
²Seat Belt Switch Sense
²Transmission Range Sensor MUX - with
Auto Trans
²Turn/Hazard Switch MUX
²Washer/Beam Select Switch MUX
²Wiper Switch MUX
Refer to the appropriate wiring information for
additional details.
HARD WIRED OUTPUTS
The hard wired outputs of the EMIC include the
following:
²Accessory Switch Bank Illumination Driver
²BTSI Driver - with Auto Trans
²Cargo Lamp Driver
²Dome/Overhead Lamp Driver
²Driver Door Unlock Driver - with Power
Locks
²Headlamp Switch Illumination Driver
²Heated Seat Switch Indicator Driver - with
Heated Seats
²Heater-A/C Control Illumination Driver
²Left Door Lock Driver - with Power Locks
²Left Rear Door Unlock Driver - with Power
Locks²Map/Glove Box Lamp Driver
²Radio Illumination Driver
²Right Door Lock Driver - with Power Locks
²Right Door Unlock Driver - with Power
Locks
²Transfer Case Switch Illumination Driver -
with Four-Wheel Drive
Refer to the appropriate wiring information for
additional details.
GROUNDS
The EMIC receives and supplies a ground path to
several switches and sensors through the following
hard wired circuits:
²Ground - Illumination (2 Circuits)
²Ground - Power Lock - with Power Locks
²Ground - Signal
²Headlamp Switch Return
²Multi-Function Switch Return
²Transmission Range Sensor Return - with
Auto Trans
Refer to the appropriate wiring information for
additional details.
COMMUNICATION
The EMIC has provisions for the following commu-
nication circuits:
²PCI Data Bus
²RKE Program Serial Data - with RKE
²RKE Transmit Serial Data - with RKE
Refer to the appropriate wiring information for
additional details.
DIAGNOSIS AND TESTING - INSTRUMENT
CLUSTER
If all of the instrument cluster gauges and/or indi-
cators are inoperative, refer to PRELIMINARY
DIAGNOSIS. If an individual gauge or Programma-
ble Communications Interface (PCI) data bus mes-
sage-controlled indicator is inoperative, refer to
ACTUATOR TEST. If an individual hard wired indi-
cator is inoperative, refer to the diagnosis and testing
information for that specific indicator.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
8J - 10 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

ACTUATOR TEST
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
The instrument cluster actuator test will put the
instrument cluster into its self-diagnostic mode. In
this mode the instrument cluster can perform a self-
diagnostic test that will confirm that the instrument
cluster circuitry, the gauges, and the indicators are
capable of operating as designed. During the actuator
test the instrument cluster circuitry will position
each of the gauge needles at various calibration
points, illuminate all of the segments in the Vacuum
Fluorescent Display (VFD) units, turn all of the indi-
cators on and off again, display any Diagnostic Trou-
ble Code (DTC) information, and display the number
of ignition key cycles that have occurred since the
DTC was detected. It is suggested that a note pad
and pencil be used to write down any fault informa-
tion that is displayed during the test for reference.
Successful completion of the actuator test will con-
firm that the instrument cluster is operational. How-
ever, there may still be a problem with the PCI data
bus, the Powertrain Control Module (PCM), the
Engine Control Module (ECM), the Front Control
Module (FCM), the Transmission Control Module
(TCM), the Transfer Case Control Module (TCCM),
the Airbag Control Module (ACM), the Controller
Anti-lock Brake (CAB), or the inputs to one of these
electronic control modules. Use a DRBIIItscan toolto diagnose these components. Refer to the appropri-
ate diagnostic information.
(1) Begin the test with the ignition switch in the
Off position.
(2) Depress the odometer/trip odometer switch but-
ton.
(3) While still holding the odometer/trip odometer
switch button depressed, turn the ignition switch to
the On position, but do not start the engine.
(4) Release the odometer/trip odometer switch but-
ton.
(5) The instrument cluster will simultaneously
illuminate all of the operational segments in both
VFD units, perform a bulb check of each operational
LED indicator. The VFD segments and LED indica-
tors remain illuminated as each gauge needle is
swept to several calibration points and back. If a
VFD segment or an LED indicator fails to illuminate,
or if a gauge needle fails to sweep through the cali-
bration points and back during this test, the instru-
ment cluster must be replaced. Following these tests,
the actuator test will proceed as described in Step 6.
(6) The text ªC Codeº is displayed in the odometer
VFD for about three seconds. If there is no stored
fault information, the display will show two pairs of
zeroes in the format ª00º ª00º, which indicate that
the display of fault information is done. If there is
stored fault information, two sets of two-digit alpha
and alpha-numeric fault codes will appear in the
odometer display for a three second interval. The
first pair of digits represents a Diagnostic Trouble
Code (DTC), or fault code for the instrument cluster.
The second pair of digits is a counter for the number
of ignition key cycles that have occurred since the
displayed DTC was set. The instrument cluster will
continue to display additional sets of two pairs of dig-
its at three second intervals until all of the stored
codes have been displayed, which is again signaled
by a code of ª00º ª00º. Refer to the Instrument Clus-
ter Failure Message table for a description of each
fault code that the instrument cluster displays. If an
instrument cluster fault is displayed, use a DRBIIIt
scan tool to diagnose the problem. Refer to the appro-
priate diagnostic information.
INSTRUMENT CLUSTER FAILURE MESSAGE
Fault Code Description Correction
01 Airbag warning indicator output circuit shorted. Refer to the appropriate diagnostic information.
02 Airbag warning indicator output circuit open. Refer to the appropriate diagnostic information.
03 ABS indicator output circuit shorted. Refer to the appropriate diagnostic information.
04 ABS indicator output circuit open. Refer to the appropriate diagnostic information.
05 MIL indicator output circuit shorted. Refer to the appropriate diagnostic information.
06 MIL indicator output circuit open. Refer to the appropriate diagnostic information.
8J - 12 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The secu-
rity indicator is serviced as a unit with the instru-
ment cluster.
OPERATION
The security indicator gives an indication to the
vehicle operator when the Vehicle Theft Security Sys-
tem (VTSS) is arming or is armed. On models
equipped with the Sentry Key Immobilizer System
(SKIS), the security indicator also gives an indication
to the vehicle operator of the status of the SKIS. This
indicator is controlled by a transistor on the instru-
ment cluster circuit board based upon cluster pro-
gramming, hard wired inputs to the cluster from the
various security system components, electronic mes-
sages received by the cluster from the Remote Key-
less Entry (RKE) receiver module over a dedicated
serial bus, and electronic messages received by the
cluster from the Sentry Key Immobilizer Module
(SKIM) over the Programmable Communications
Interface (PCI) data bus. The security indicator Light
Emitting Diode (LED) is completely controlled by the
instrument cluster logic circuit, and that logic will
allow this indicator to operate whenever the instru-
ment cluster receives a battery current input on the
fused B(+) circuit. Therefore, the LED can be illumi-
nated regardless of the ignition switch position. The
LED only illuminates when it is provided a path to
ground by the instrument cluster transistor. The
instrument cluster will turn on the security indicator
for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position, the SKIM tells the cluster
to illuminate the SKIS indicator for about two sec-
onds as a bulb test.
²VTSS Indication- During the sixteen second
VTSS arming function, the cluster will flash the
security indicator on and off repeatedly at a steady,
fast rate to indicate that the VTSS is in the process
of arming. Following successful VTSS arming, the
cluster flashes the security indicator on and off con-
tinuously at a slower rate to indicate that the VTSS
is armed. The security indicator continues flashing at
the slower rate until the VTSS is disarmed or trig-
gered. If the VTSS has alarmed and rearmed, the
cluster will flash the security indicator at a steady,
slow rate for about thirty seconds after the VTSS is
disarmed.
²SKIM Lamp-On Message- Each time the clus-
ter receives a lamp-on message from the SKIM, the
security indicator will be illuminated. The indicator
can be flashed on and off, or illuminated solid, as dic-
tated by the SKIM message. The indicator remains
illuminated solid or continues to flash until the clus-
ter receives a lamp-off message from the SKIM, oruntil the ignition switch is turned to the Off position,
whichever occurs first. For more information on the
SKIS and the security indicator control parameters,
(Refer to 8 - ELECTRICAL/VEHICLE THEFT SECU-
RITY/SENTRY KEY IMMOBILIZER SYSTEM -
OPERATION).
²Communication Error- If the cluster receives
no SKIS lamp-on or lamp-off messages from the
SKIM for twenty consecutive seconds, the SKIS indi-
cator is illuminated by the instrument cluster. The
indicator remains controlled and illuminated by the
cluster until a valid SKIS lamp-on or lamp-off mes-
sage is received from the SKIM.
²Actuator Test- Each time the instrument clus-
ter is put through the actuator test, the security indi-
cator will be turned on, then off again during the
bulb check portion of the test to confirm the function-
ality of the LED and the cluster control circuitry.
The instrument cluster circuitry controls the secu-
rity indicator whenever the ignition switch is in the
Off position and the VTSS is arming, armed, or
alarming. Whenever the ignition switch is in the On
or Start positions, the SKIM performs a self-test to
decide whether the SKIS is in good operating condi-
tion and whether a valid key is present in the igni-
tion lock cylinder. The SKIM then sends the proper
lamp-on or lamp-off messages to the instrument clus-
ter. For further diagnosis of the security indicator or
the instrument cluster circuitry that controls the
indicator, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). If the
instrument cluster flashes the SKIS indicator upon
ignition On, or turns on the SKIS indicator solid
after the bulb test, it indicates that a SKIS malfunc-
tion has occurred or that the SKIS is inoperative. For
proper diagnosis of the VTSS, the SKIS, the SKIM,
the PCI data bus, or the electronic message inputs to
the instrument cluster that control the security indi-
cator, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
SERVICE 4WD INDICATOR
DESCRIPTION
A service 4WD indicator is standard equipment on
all instrument clusters (Fig. 27). However, on vehi-
cles not equipped with the optional four-wheel drive
system and electronically shifted transfer case, this
indicator is electronically disabled. The service 4WD
indicator consists of the text ªSERV 4WDº, which
Fig. 27 Service 4WD Indicator
8J - 36 INSTRUMENT CLUSTERDR
SECURITY INDICATOR (Continued)

appears in the lower portion of the odometer/trip
odometer Vacuum Fluorescent Display (VFD) unit.
The VFD is soldered onto the cluster electronic cir-
cuit 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 the indicator from
being clearly visible when it is not illuminated. The
text ªSERV 4WDº appears in an amber color and at
the same lighting level as the odometer/trip odometer
information when they are illuminated by the instru-
ment cluster electronic circuit board. The service
4WD indicator is serviced as a unit with the VFD in
the instrument cluster.
OPERATION
The service 4WD indicator gives an indication to
the vehicle operator when the Transfer Case Control
Module (TCCM) has recorded a Diagnostic Trouble
Code (DTC) for an electronic transfer case circuit or
component malfunction. This indicator is controlled
by a transistor on the instrument cluster circuit
board based upon cluster programming and elec-
tronic messages received by the cluster from the
TCCM over the Programmable Communications
Interface (PCI) data bus. The service 4WD indicator
is completely controlled by the instrument cluster
logic circuit, and that logic will only allow this indi-
cator to operate when the instrument cluster receives
a battery current input on the fused ignition switch
output (run-start) circuit. Therefore, the indicator
will always be off when the ignition switch is in any
position except On or Start. The indicator only illu-
minates when it is switched to ground by the instru-
ment cluster circuitry. The instrument cluster will
turn on the service 4WD indicator for the following
reasons:
²Service 4WD Lamp-On Message- Each time
the cluster receives a service 4WD lamp-on message
from the TCCM, the indicator will be illuminated.
The indicator remains illuminated until the cluster
receives a service 4WD lamp-off message from the
TCCM, or until the ignition switch is turned to the
Off position, whichever occurs first.
²Communication Error- If the cluster receives
no messages from the TCCM for five seconds, the
service 4WD indicator is illuminated by the instru-
ment cluster to indicate a loss of TCCM communica-
tion. The indicator remains controlled and
illuminated by the cluster until a valid message is
received from the TCCM.
²Actuator Test- Each time the cluster is put
through the actuator test, the service 4WD indicator
will be turned on, then off again during the VFD por-
tion of the test to confirm the functionality of the
VFD and the cluster control circuitry.The TCCM continually monitors the electronic
transfer case switch and circuits to determine the
condition of the system. The TCCM then sends the
proper lamp-on or lamp-off messages to the instru-
ment cluster. For further diagnosis of the service
4WD indicator or the instrument cluster circuitry
that controls the VFD, (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). For proper diagnosis of the TCCM, the
PCI data bus, or the electronic message inputs to the
instrument cluster that control the service 4WD indi-
cator, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
SPEEDOMETER
DESCRIPTION
A speedometer is standard equipment on all instru-
ment clusters. The speedometer is located next to the
tachometer, just to the right of center in the instru-
ment cluster. The speedometer consists of a movable
gauge needle or pointer controlled by the instrument
cluster circuitry and a fixed 210 degree primary scale
on the gauge dial face that reads left-to-right either
from ª0º to ª120º mph, or from ª0º to ª200º km/h,
depending upon the market for which the vehicle is
manufactured. Each version also has a secondary
inner scale on the gauge dial face that provides the
equivalent opposite units from the primary scale.
Text appearing on the cluster overlay just below the
hub of the speedometer needle abbreviates the unit
of measure for the primary scale (i.e.: MPH or km/h),
followed by the unit of measure for the secondary
scale (Fig. 28). The speedometer graphics are black
(primary scale) and blue (secondary scale) against a
white field, 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 dark blue and
the blue graphics appear light blue. The orange
gauge needle is internally illuminated. Gauge illumi-
nation is provided by replaceable incandescent bulb
and bulb holder units located on the instrument clus-
ter electronic circuit board. The speedometer is ser-
viced as a unit with the instrument cluster.
OPERATION
The speedometer gives an indication to the vehicle
operator of the vehicle road speed. This gauge is con-
Fig. 28 Speedometer Text
DRINSTRUMENT CLUSTER 8J - 37
SERVICE 4WD INDICATOR (Continued)

(3) Install the bolts attaching headlamp unit to the
fender (Fig. 11).
(4) Align the seal and install the push pins.
(5) Connect the battery negative cable.
ADJUSTMENTS
Headlamps can be aligned using the screen method
provided in this section.
LAMP 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. 12).
(2) If necessary, tape a line on the floor 7.62
meters (25 ft) away from and parallel to the wall.
(3) Up 1.27 meters (5 feet) from the floor, tape a
line on the wall at the centerline of the vehicle. Sight
along the centerline of the vehicle (from rear of vehi-
cle forward) to verify accuracy of the line placement.
(4) Rock vehicle side-to-side three times to allow
suspension to stabilize.
(5) Jounce front suspension three times by pushing
downward on front bumper and releasing.
(6) Measure the distance from the center of head-
lamp lens to the floor. Transfer measurement to thealignment screen (with tape). Use this line for
up/down adjustment reference.
(7) Measure distance from the centerline of the
vehicle to the center of each headlamp being aligned.
Transfer measurements to screen (with tape) to each
side of vehicle centerline. Use these lines for left/
right adjustment reference.
VEHICLE PREPARATION FOR HEADLAMP
ALIGNMENT
(1) Verify headlamp dimmer switch and high beam
indicator operation.
(2) Correct defective components that could hinder
proper headlamp alignment.
(3) Verify proper tire inflation.
(4) Clean headlamp lenses.
(5) Verify that luggage area is not heavily loaded.
(6) 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.
HEADLAMP ALIGNMENT
A properly aimed low beam headlamp will project
top edge of high intensity pattern on screen from 50
mm (2 in.) above to 50 mm (2 in.) below headlamp
Fig. 12 Headlamp Alignment Screen - Typical
1 - CENTER OF VEHICLE
2 - CENTER OF HEADLAMP3 - 7.62 METERS (25 FT.)
4 - FRONT OF HEADLAMP
8L - 16 LAMPS/LIGHTING - EXTERIORDR
HEADLAMP UNIT (Continued)