service reset DODGE RAM 2002 Service User Guide

(3) Engage the two mounting hooks on the rear of
the overhead console housing in the mounting holes
in the inner roof panel.
(4) Slide the overhead console forward far enough
to align the two latches on the front of the housing
with their receptacles in the inner roof panel.
(5) Push upward firmly and evenly on the front of
the overhead console until each of the two latches is
fully engaged in its receptacle in the inner roof panel.
(6) Close the garage door opener storage bin door.
(7) Reconnect the battery negative cable.
SPECIAL TOOLS
OVERHEAD CONSOLE SPECIAL TOOL
COMPASS/MINI-TRIP
COMPUTER
DESCRIPTION
The compass mini-trip computer is located in the
premium overhead console on models equipped with
this option. Two compass mini-trip computer units
are available. One unit is used on vehicles not
equipped with the Vehicle Theft Security System
(VTSS) option, and the other is used on vehicles with
the VTSS option. Both compass mini-trip computer
units include the electronic control module, a Vacu-
um-Fluorescent Display (VFD), a compass flux-gate
unit and two push button function switches.
Compass mini-trip computer units for vehicles
equipped with the VTSS include a red Light-Emit-
ting Diode (LED) on their electronic circuit board.
This LED protrudes through the bottom of the lens
on the front of the overhead console unit, and serves
as the security indicator lamp. Refer toSecurity
Indicator Lampin Vehicle Theft/Security Systems
for more information on this feature.
The compass mini-trip computer module contains a
central processing unit and interfaces with other
electronic modules in the vehicle on the Chrysler Col-
lision Detection (CCD) data bus network. The CCD
data bus network allows the sharing of sensor infor-
mation. This helps to reduce wire harness complexity,
reduce internal controller hardware, and reduce com-
ponent sensor current loads. At the same time, thissystem provides increased reliability, enhanced diag-
nostics, and allows the addition of many new feature
capabilities.
The compass mini-trip computer provides several
electronic functions and features. Some of the func-
tions and features that the compass mini-trip com-
puter module supports and/or controls, include the
following display options:
²Compass and temperature- provides the out-
side temperature and one of eight compass readings
to indicate the direction the vehicle is facing.
²Compass and compass in degrees- provides
one of eight compass readings to indicate the direc-
tion the vehicle is facing and provides the compass
direction in degrees.
²Trip odometer (ODO)- shows the distance
travelled since the last trip computer reset.
²Average fuel economy (AVG ECO)- shows
the average fuel economy since the last trip computer
reset.
²Instant fuel economy (ECO)- shows the
present fuel economy based upon the current vehicle
distance and fuel used information.
²Distance to empty (DTE)- shows the esti-
mated distance that can be travelled with the fuel
remaining in the fuel tank. This estimated distance
is computed using the average miles-per-gallon from
the last 30 gallons of fuel used.
²Elapsed time (ET)- shows the accumulated
ignition-on time since the last trip computer reset.
²Blank screen- the compass mini-trip VFD is
turned off.
The ambient temperature sensor is hard wired to
the compass mini-trip computer module. Data input
for all other compass mini-trip computer functions,
including VFD dimming level, is received through
CCD data bus messages. The compass mini-trip com-
puter uses its internal programming and all of these
inputs to calculate and display the requested data. If
the data displayed is incorrect, perform the self-diag-
nostic tests as described in this group. If these tests
prove inconclusive, the use of a DRBIIItscan tool
and the proper Diagnostic Procedures manual are
recommended for further testing of the compass
mini-trip computer module and the CCD data bus.
The compass mini-trip computer module cannot be
repaired, and is available for service only as a unit. If
faulty or damaged, the complete module must be
replaced.
OPERATION
The compass mini-trip computer only operates with
the ignition switch in the On position. When the igni-
tion switch is turned to the On position, all of the
segments in the compass mini-trip computer VFD
will be turned on for one second, then the display
Degaussing Tool 6029
BR/BEMESSAGE SYSTEMS 8M - 9
OVERHEAD CONSOLE (Continued)

OPERATION
When the power lumbar switch paddle is actuated,
a battery feed and a ground path are applied through
the switch contacts to the power lumbar adjuster
motor. The motor operates to move the lumbar
adjuster through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch is
moved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the motor to run in the
opposite direction.
The power lumbar switch should not be held
applied in either direction after the adjuster has
reached its travel limit. The power lumbar adjuster
motor contains a self-resetting circuit breaker to pro-
tect it from overload. However, consecutive or fre-
quent resetting of the circuit breaker must not be
allowed to continue, or the motor may be damaged.
REMOVAL
The power lumbar switch is integral with the other
power seat switches. Refer to the appropriate driver
or passenger power front seat switch removal and/or
installation procedure.
LUMBAR MOTOR
DESCRIPTION
The power lumbar seat option includes an electri-
cally operated lumbar support mechanism. The only
visible evidence of this option is the separate power
lumbar switch control paddle that is located on the
outboard seat cushion side shield, next to the other
power seat switch control knobs. The power lumbar
adjuster and motor are concealed beneath the seat
back trim cover and padding, where they are secured
to a molded plastic back panel and to the seat back
frame.
The power lumbar adjuster cannot be repaired, and
is serviced only as a unit with the seat back frame. If
the power lumbar adjuster or the seat back frame
are damaged or faulty, the entire seat back frame
unit must be replaced (Refer to 23 - BODY/SEATS/
SEAT BACK - REMOVAL).
OPERATION
The power lumbar adjuster mechanism includes a
reversible electric motor that is secured to the
inboard side of the seat back panel and is connected
to a worm-drive gearbox. The motor and gearbox
operate the lumbar adjuster mechanism in the center
of the seat back by extending and retracting a cable
that actuates a lever. The action of this lever com-
presses or relaxes a grid of flexible slats. The morethis grid is compressed, the more the slats bow out-
ward against the center of the seat back padding,
providing additional lumbar support.
DIAGNOSIS AND TESTING - LUMBAR MOTOR
Actuate the power lumbar switch to move the
power lumbar adjuster in each direction. The power
lumbar adjuster should move in both directions. It
should be noted that the power lumber adjuster nor-
mally operates very quietly and exhibits little visible
movement. If the power lumbar adjuster fails to oper-
ate in only one direction, move the adjuster a short
distance in the opposite direction and test again to be
certain that the adjuster is not at its travel limit. If
the power lumbar adjuster still fails to operate in
only one direction, (Refer to 8 - ELECTRICAL/
POWER SEATS/DRIVER SEAT SWITCH - DIAGNO-
SIS AND TESTING). If the power lumbar adjuster
fails to operate in either direction, perform the fol-
lowing tests. For complete circuit diagrams, refer to
Wiring Diagrams.
(1) Check the power seat circuit breaker in the
junction block. If OK, go to Step 2. If not OK, replace
the faulty power seat circuit breaker.
(2) Check for battery voltage at the power seat cir-
cuit breaker in the junction block. If OK, go to Step
3. If not OK, repair the open fused B(+) circuit to the
fuse in the Power Distribution Center as required.
(3) Remove the outboard seat cushion side shield
from the seat. Disconnect the seat wire harness con-
nector from the power lumbar switch connector
receptacle. Check for battery voltage at the fused
B(+) circuit cavity of the power seat wire harness
connector for the power lumbar switch. If OK, go to
Step 4. If not OK, repair the open fused B(+) circuit
to the power seat circuit breaker in the junction
block as required.
(4) Check for continuity between the ground cir-
cuit cavity of the power seat wire harness connector
for the power lumbar switch and a good ground.
There should be continuity. If OK, go to Step 5. If not
OK, repair the open ground circuit to ground as
required.
(5) Test the power lumbar switch. . If the switch
tests OK, test the circuits of the power seat wire har-
ness between the power lumbar adjuster motor and
the power lumbar switch for shorts or opens. If the
circuits check OK, replace the faulty seat back frame
assembly. If the circuits are not OK, repair the power
seat wire harness as required.
BR/BEPOWER SEAT SYSTEM 8N - 19
LUMBAR CONTROL SWITCH (Continued)

Each motor contains a self-resetting circuit breaker
to protect it from overload. Consecutive or frequent
resetting of the circuit breakers must not be allowed
to continue, or the motors may be damaged.
The power seat adjuster and motors cannot be
repaired, and are serviced only as a complete unit. If
any component in this unit is faulty or damaged, the
entire power seat adjuster and motors assembly must
be replaced.
OPERATION
When a power seat switch is actuated, a battery
feed and a ground path are applied through the
power seat switch contacts to the appropriate motor
or motors. The motor and drive unit operate to move
the seat in the selected direction until the switch is
released, or until the travel limit of the power seat
track is reached. When the switch is moved in the
opposite direction, the battery feed and ground path
to the motor is reversed through the switch contacts.
This causes the motor to run in the opposite direc-
tion.
DIAGNOSIS AND TESTING - POWER SEAT
TRACK
For complete power seat circuit descriptions and
diagrams, refer to Wiring Diagrams.
Operate the power seat switch to move all three
seat motors in each direction. The seat should move
in each of the selected directions. If the power seat
track fails to operate in only one direction, move the
seat track a short distance in the opposite direction
and test again to be certain that the track is not at
its travel limit. If the power seat track still fails to
operate in only one direction, refer to Diagnosis and
Testing of the Power Seat Switch in this section. If
the power seat track fails to operate in more than
one direction, proceed as follows:
(1) Check the power seat fuse in the power distri-
bution center. If OK, go to Step 2. If not OK, replace
the faulty fuse.
(2) Remove the power seat switch from the seat.
Check for battery voltage at the fused B(+) circuit
cavity of the power seat switch wire harness connec-
tor. If OK, go to Step 3. If not OK, repair the open
circuit to the power distribution center as required.(3) Check for continuity between the ground cir-
cuit cavity of the power seat switch wire harness con-
nector and a good ground. There should be
continuity. If OK, go to Step 4. If not OK, repair the
open circuit to ground as required.
(4) Test the power seat switch as described in this
group. If the switch tests OK, check the wire harness
between the power seat switch and the motor for
shorts or opens. If the circuits check OK, replace the
faulty power seat track (adjuster) assembly. If the
circuits are not OK, repair the wire harness as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the seat, power seat track from the
vehicle as a unit (Refer to 23 - BODY/SEATS/SEAT -
REMOVAL).
(3) Unplug the power seat wire harness connectors
at each of the three power seat motors.
(4) Release the power seat wire harness retainers
from the seat track.
(5) Remove the fasteners that secure the center
seat cushion section to the brackets on the power
seat track.
(6) Remove the screws that secure the power seat
track assembly to the seat cushion frame.
(7) Remove the power seat track assembly from
the seat cushion frame.
INSTALLATION
(1) Position the power seat track assembly on the
seat cushion frame.
(2) Install the fasteners that secure the center seat
cushion section to the brackets on the power seat
adjuster.
(3) Install the screws that secure the power seat
track assembly to the seat cushion frame.
(4) Connect the power seat wire harness connec-
tors at each of the three power seat motors.
(5) Install the power seat wire harness retainers
on the seat track assembly.
(6) Install the seat, power seat track as a unit
(Refer to 23 - BODY/SEATS/SEAT - INSTALLA-
TION).
(7) Connect the battery negative cable.
8N - 22 POWER SEAT SYSTEMBR/BE
POWER SEAT TRACK (Continued)

INSTALLATION
(1) Connect the power window switch to the har-
ness connector.
(2) Insert the rear of the switch and bezel unit into
the opening.
(3) Push down on the front and rear of the switch
until the retaining tabs snap into place.
(4) Reconnect the battery negative cable.
WINDOW MOTOR
DESCRIPTION
A permanent magnet reversible motor moves the
window regulator through an integral gearbox mech-
anism. A positive and negative battery connection to
the two motor terminals will cause the motor to
rotate in one direction. Reversing the current
through these same two connections will cause the
motor to rotate in the opposite direction.
In addition, each power window motor is equipped
with an integral self-resetting circuit breaker to pro-
tect the motor from overloads. The power window
motor and gearbox assembly cannot be repaired and,
if faulty or damaged, the entire power window regu-
lator assembly must be replaced.
DIAGNOSIS AND TESTING - WINDOW MOTOR
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds. Before you proceed withthis diagnosis, confirm proper switch operation.
(Refer to 8 - ELECTRICAL/POWER WINDOWS/
POWER WINDOW SWITCH - DIAGNOSIS AND
TESTING).
(1) Disconnect and isolate the battery negative
cable. Remove the trim panel from the door with the
inoperative power window.
(2) Unplug the power window motor wire harness
connector. Apply 12 volts across the motor terminals
to check its operation in one direction. Reverse the
connections across the motor terminals to check the
operation in the other direction. Remember, if the
window is in the full up or full down position, the
motor will not operate in that direction by design. If
OK, repair the circuits from the power window motor
to the power window switch as required. If not OK,
replace the faulty motor.
(3) If the motor operates in both directions, check
the operation of the window glass and lift mechanism
through its complete up and down travel. There
should be no binding or sticking of the window glass
or lift mechanism through the entire travel range. If
not OK, (Refer to 23 - BODY/DOOR - FRONT/WIN-
DOW REGULATOR - REMOVAL).
REMOVAL
The power window motor and mechanism is inte-
gral to the power window regulator unit. If the power
window motor or mechanism is faulty or damaged,
the entire power window regulator unit must be
replaced. (Refer to 23 - BODY/DOOR - FRONT/WIN-
DOW REGULATOR - REMOVAL) for the window
regulator service procedures.
8N - 26 POWER WINDOWSBR/BE
POWER WINDOW SWITCH (Continued)

(8) Remove the cigar lighter or power outlet mount
from the instrument panel.
INSTALLATION
(1) Reconnect the instrument panel wire harness
connector to the cigar lighter or power outlet recep-
tacle base connector receptacle.
(2) Install the cigar lighter or power outlet mount
into the instrument panel.
(3) Align the splines on the outside of the cigar
lighter or power outlet receptacle base connector
receptacle with the grooves on the inside of the
mount.
(4) Press firmly on the cigar lighter or power out-
let receptacle base until the retaining bosses of the
mount are fully engaged in their receptacles.
(5) Install the cigar lighter knob and element into
the cigar lighter receptacle base, or the protective cap
into the power outlet receptacle base.
(6) Reconnect the battery negative cable.
CIRCUIT BREAKER
DESCRIPTION
Automatic resetting circuit breakers are used to
protect a system circuit from a short circuit or over-
load. Some examples of his condition can be caused
by an obstructed or stuck seat adjuster or power win-
dow motor.
The circuit breaker cannot be repaired and, if
faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - CIRCUIT BREAKER
For circuit descriptions and diagrams, refer to Wir-
ing Diagrams.
(1) Locate the correct circuit breaker in the junc-
tion block. Pull out the circuit breaker slightly, but
be certain that the circuit breaker terminals still con-
tact the terminals in the junction block cavities.
(2) Connect the negative lead of a 12-volt DC volt-
meter to a good ground.
(3) With the voltmeter positive lead, check both
terminals of the circuit breaker for battery voltage.
If only one terminal has battery voltage, the circuit
breaker is faulty and must be replaced. If neither ter-
minal has battery voltage, repair the open circuit
from the Power Distribution Center (PDC) as
required.
GENERATOR CARTRIDGE
FUSE
DESCRIPTION
A 140 ampere generator cartridge fuse is used on
this model. The generator cartridge fuse is similar to
other cartridge fuses found in the Power Distribution
Center (PDC). This fuse has a color-coded plastic
housing and a clear plastic fuse conductor inspection
cover like other cartridge fuses, but has a higher cur-
rent rating and is connected and secured with screws
instead of being pushed onto male spade-type termi-
nals. The generator cartridge fuse cannot be repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The generator cartridge fuse is secured between
the two B(+) terminal stud connection bus bars
within the Power Distribution Center (PDC). This
fuse protects the vehicle electrical system from dam-
age that could be caused by excessive charging sys-
tem output and/or excessive electrical system current
levels resulting from a faulty generator or faulty
charging system control circuits. If the current rating
of the fuse is exceeded, the fuse conductor melts to
open the generator output circuit connection to the
PDC. If a generator cartridge fuse fails, be certain to
completely inspect and test the vehicle charging sys-
tem before replacing the fuse and returning the vehi-
cle to service. Refer toCharging Systemfor the
charging system diagnostic procedures. Refer toWir-
ing Diagramsfor the location of complete PDC cir-
cuit diagrams.
REMOVAL
If a generator cartridge fuse fails, be certain to
inspect and test the vehicle charging system before
replacing the cartridge fuse and returning the vehicle
to service. Refer toCharging Systemin the index of
this service manual for the charging system diagnos-
tic procedures.
(1) Disconnect and isolate the battery negative
cable.
(2) Unlatch and remove the cover from the Power
Distribution Center (PDC).
(3) Remove the two screws that secure the genera-
tor cartridge fuse to the two B(+) terminal stud bus
bars within the PDC.
(4) Remove the generator cartridge fuse from the
PDC.
INSTALLATION
If a generator cartridge fuse fails, be certain to
inspect and test the vehicle charging system before
replacing the cartridge fuse and returning the vehicle
8W - 97 - 4 8W-97 POWER DISTRIBUTIONBR/BE
CIGAR LIGHTER OUTLET (Continued)

tor between many of the engine compartment, instru-
ment panel, and body wire harnesses. The JB houses
up to nineteen blade-type fuses (two standard-type
and seventeen mini-type), up to two blade-type auto-
matic resetting circuit breakers, the electronic combi-
nation turn signal and hazard warning flasher, and
one International Standards Organization (ISO)
micro-relay.
The molded plastic JB housing has integral mount-
ing brackets that are secured with two screws to the
left instrument panel end bracket. The left end of the
instrument panel cover has a snap-fit fuse access
panel that can be removed for service of the JB. A
fuse puller and spare fuse holders are located on the
back of the fuse access cover, as well as an adhesive-
backed fuse layout map to ensure proper fuse identi-
fication.
The JB unit cannot be repaired and is only ser-
viced as an assembly. If any internal circuit or the JB
housing is faulty or damaged, the entire JB unit
must be replaced.
OPERATION
All of the circuits entering and leaving the JB do
so through up to nine wire harness connectors, which
are connected to the JB through integral connector
receptacles molded into the JB housing. Internal con-
nection of all of the JB circuits is accomplished by an
intricate combination of hard wiring and bus bars.
Refer toWiring Diagramsfor the location of com-
plete JB circuit diagrams.
DIAGNOSIS AND TESTING - JUNCTION BLOCK
The junction block does not incorporate any self
diagnostic capability. Most of the electrical circuits
incorporated into the vehicle must pass through the
junction block at one point or another. The most effi-
cient means of diagnosing a suspected junction block
problem involves a simple continuity tester or ohm
meter. Using the Wiring Diagrams as a guide trace
the problem circuit to the proper junction block cav-
ity and test all circuits in the effected circuit for
proper continuity. A open or high resistance circuit is
a sign of a problem. Some other possible junction
block problems to look for are:
²Loose fuse receptacle terminals.
²Loose relay / circuit breaker receptacle termi-
nals.
²Bent or distorted electrical circuit pins.
²Incorrect size fuse installed in junction block
fuse cavity.
²Dark areas identifying a source of excess heat.
²Defective fuse, relay or circuit breaker installed
in junction block cavity.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the fuse access bezel from the instru-
ment panel.
(3) Remove the steering column cover (Refer to 23
- BODY/INSTRUMENT PANEL/STEERING COL-
UMN OPENING COVER - REMOVAL).
(4) Remove the hood release handle retaining
screws and position the handle assembly out of the
way.
(5) Remove the lower knee blocker from the instru-
ment panel.
(6) Pull drivers side carpet down, out of the way.
(7) Remove the parking brake switch connector,
release linkage and retaining fasteners and position
the assembly out the drivers door opening.
(8) Remove the electrical ground connections,
located behind park brake mounting location.
(9) Remove the two junction block retaining
screws. To access the upper retaining screw a 15 inch
long #2 Phillips screwdriver will be required. Access
the upper screw through hole in dash support brace.
(10) Reach through the outboard side of the instru-
ment panel steering column opening to access and
disconnect all of the wire harness connectors from
the Junction Block (JB) connector receptacles (Fig.
6).
Fig. 6 Junction Block Remove/Install
1 - I.P. End Bracket
2 - Junction Block
3 - Screws
BR/BE8W-97 POWER DISTRIBUTION 8W - 97 - 7
JUNCTION BLOCK (Continued)