reset DODGE RAM 2001 Service User Guide
Page 583 of 2889
MALFUNCTION INDICATOR
LAMP (MIL)
DESCRIPTION
A Malfunction Indicator Lamp (MIL) is standard
equipment on all instrument clusters. The MIL is
located near the lower edge of the instrument cluster
overlay, to the left of center. The MIL consists of a
stencilled cutout of the International Control and
Display Symbol icon for ªEngineº in the opaque layer
of the instrument cluster overlay. The dark outer
layer of the overlay prevents the indicator from being
clearly visible when it is not illuminated. An amber
lens behind the cutout in the opaque layer of the
overlay causes the icon to appear in amber through
the translucent outer layer of the overlay when the
indicator is illuminated from behind by a Light Emit-
ting Diode (LED) soldered onto the instrument clus-
ter electronic circuit board. The MIL is serviced as a
unit with the instrument cluster.
OPERATION
The Malfunction Indicator Lamp (MIL) gives an
indication to the vehicle operator when the Power-
train Control Module (PCM) has recorded a Diagnos-
tic Trouble Code (DTC) for an On-Board Diagnostics
II (OBDII) emissions-related circuit or component
malfunction. In addition, on models with a diesel
engine an Engine Control Module (ECM) supple-
ments the PCM, and can also record an OBDII DTC.
The MIL is controlled by a transistor on the instru-
ment cluster circuit board based upon cluster pro-
gramming and electronic messages received by the
cluster from the PCM or ECM over the Chrysler Col-
lision Detection (CCD) data bus. The MIL Light
Emitting Diode (LED) receives battery current on the
instrument cluster electronic circuit board through
the fused ignition switch output (st-run) circuit
whenever the ignition switch is in the On or Start
positions; therefore, the LED will always be off when
the ignition switch is in any position except On or
Start. The LED only illuminates when it is provided
a path to ground by the instrument cluster transis-
tor. The instrument cluster will turn on the MIL for
the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the indicator is illuminated
for about seven seconds as a bulb test.
²PCM Lamp-On Message- Each time the clus-
ter receives a lamp-on message from the PCM or
ECM, the indicator will be illuminated. The indicator
can be flashed on and off, or illuminated solid, as dic-
tated by the PCM/ECM message. For some DTC's, if
a problem does not recur, the PCM or ECM will send
a lamp-off message automatically. Other DTC's mayrequire that a fault be repaired and the PCM or
ECM be reset before a lamp-off message will be sent.
For more information on the PCM, the ECM, and the
DTC set and reset parameters, (Refer to 25 - EMIS-
SIONS CONTROL - OPERATION).
²Communication Error- If the cluster receives
no lamp-on message from the PCM or ECM for
twenty seconds, the MIL is illuminated by the instru-
ment cluster to indicate a loss of bus communication.
The indicator remains controlled and illuminated by
the cluster until a valid lamp-on message is received
from the PCM or ECM.
²Actuator Test- Each time the cluster is put
through the actuator test, the indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
The PCM/ECM continually monitor the fuel and
emissions system circuits and sensors to decide
whether the system is in good operating condition.
The PCM/ECM then sends the proper lamp-on or
lamp-off messages to the instrument cluster. For fur-
ther diagnosis of the MIL or the instrument cluster
circuitry that controls the LED, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). If the instrument cluster turns on
the MIL after the bulb test, it may indicate that a
malfunction has occurred and that the fuel and emis-
sions systems may require service. For proper diag-
nosis of the fuel and emissions systems, the PCM,
the ECM, the CCD data bus, or the message inputs
to the instrument cluster that control the MIL, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
ODOMETER
DESCRIPTION
An odometer and trip odometer are standard
equipment in all instrument clusters. The odometer
and trip odometer information are displayed in a
common electronic Vacuum-Fluorescent Display
(VFD), which is visible through a small window cut-
out located in the left lower quadrant of the cluster
overlay. However, the odometer and trip odometer
information are not displayed simultaneously. The
trip odometer reset switch on the instrument cluster
circuit board toggles the display between odometer
and trip odometer modes by depressing the odometer/
trip odometer switch knob that extends through the
lower edge of the cluster lens, just right of the
tachometer. Both the odometer and the trip odometer
information is stored in the instrument cluster mem-
ory.
8J - 24 INSTRUMENT CLUSTERBR/BE
Page 584 of 2889
The odometer can display values up to 499,999
kilometers (499,999 miles). The odometer latches at
these values, and will not roll over to zero. The trip
odometer can display values up to 999.9 kilometers
(999.9 miles) before it rolls over to zero. The odome-
ter display does not have a decimal point and will
not show values less than a full unit (kilometer or
mile), the trip odometer display does have a decimal
point and will show tenths of a unit (kilometer or
mile). The unit of measure (kilometers or miles) for
the odometer and trip odometer display is not shown
in the VFD. The unit of measure for the instrument
cluster odometer/trip odometer is selected at the time
that it is manufactured, and cannot be changed. Dur-
ing daylight hours (exterior lamps Off) the VFD is
illuminated at full brightness for clear visibility. At
night (exterior lamps are On) the VFD lighting level
is adjusted with the other cluster illumination lamps
using the panel lamps dimmer thumbwheel on the
headlamp switch. However, a ªParadeº mode position
of the panel lamps dimmer thumbwheel allows the
VFD to be illuminated at full brightness while the
exterior lamps are turned On during daylight hours.
The VFD, the trip odometer switch, and the trip
odometer switch button are serviced as a unit with
the instrument cluster.
OPERATION
The odometer and trip odometer give an indication
to the vehicle operator of the distance the vehicle has
traveled. This gauge is controlled by the instrument
cluster circuit board based upon the cluster program-
ming and electronic messages received by the cluster
from the Powertrain Control Module (PCM) over the
Chrysler Collision Detection (CCD) data bus. The
odometer and trip odometer information is displayed
by the instrument cluster Vacuum Fluorescent Dis-
play (VFD), and the VFD will not display odometer
or trip odometer information after the ignition switch
is turned to the Off position. The instrument cluster
circuitry controls the VFD and provides the following
features:
²Odometer/Trip Odometer Display Toggling-
Actuating the trip odometer reset switch momen-
tarily with the ignition switch in the On position will
toggle the VFD between the odometer and trip odom-
eter display. Each time the ignition switch is turned
to the On position the VFD will automatically return
to the mode (odometer or trip odometer) last dis-
played when the ignition switch was turned to the
Off position.
²Trip Odometer Reset- When the trip odome-
ter reset switch is pressed and held for longer than
about two seconds, the trip odometer will be reset to
000.0 kilometers (miles). The VFD must be display-ing the trip odometer information in order for the
trip odometer information to be reset.
²Message Failure- If the cluster fails to receive
a distance message during normal operation, it will
flash the odometer/trip odometer distance informa-
tion on and off repeatedly until a distance message is
received, or until the ignition switch is turned to the
Off position, whichever occurs first. If the cluster
does not receive a distance message within one sec-
ond after the ignition switch is turned to the On posi-
tion, it will display the last distance message stored
in the cluster memory. If the cluster is unable to dis-
play distance information due to an error internal to
the cluster, the VFD display will be blank.
²Actuator Test- Each time the cluster is put
through the actuator test, the VFD will display all of
its characters at once, then step through each char-
acter segment individually during the VFD portion of
the test to confirm the functionality of the VFD and
the cluster control circuitry.
The PCM continually monitors the vehicle speed
sensor, then sends the proper distance messages to
the instrument cluster. For further diagnosis of the
odometer/trip odometer or the instrument cluster cir-
cuitry that controls these functions, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the
vehicle speed sensor, the PCM, the CCD data bus, or
the message inputs to the instrument cluster that
control the odometer/trip odometer, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
OIL PRESSURE GAUGE
DESCRIPTION
An oil pressure gauge is standard equipment on all
instrument clusters. The oil pressure gauge is located
in the upper right quadrant of the instrument clus-
ter, above the fuel gauge. The oil pressure gauge con-
sists of a movable gauge needle or pointer controlled
by the instrument cluster circuitry and a fixed 90
degree scale on the cluster overlay that reads left-to-
right either from 0 kPa (0 psi) to 758 kPa (110 psi).
An International Control and Display Symbol icon for
ªEngine Oilº is located on the cluster overlay, directly
below the highest graduation of the gauge scale. The
oil pressure gauge graphics are white against a black
field except for a single red graduation at the low
end of the gauge scale, making them clearly visible
within the instrument cluster in daylight. When illu-
minated from behind by the panel lamps dimmer
controlled cluster illumination lighting with the exte-
rior lamps turned On, the white graphics appear
blue-green and the red graphics appear red. The
BR/BEINSTRUMENT CLUSTER 8J - 25
ODOMETER (Continued)
Page 587 of 2889
turn on the seatbelt indicator for the following rea-
sons:
²Seatbelt Reminder Function- Each time the
cluster receives a battery current input on the fused
ignition switch output (st-run) circuit, the indicator
will be illuminated as a seatbelt reminder for about
seven seconds, or until the ignition switch is turned
to the Off position, whichever occurs first. This
reminder function will occur regardless of the status
of the seatbelt switch input to the cluster.
²Driver Side Front Seatbelt Not Buckled-
Following the seatbelt reminder function, each time
the cluster receives a ground input on the seat belt
switch sense circuit (seatbelt switch closed - seatbelt
unbuckled) with the ignition switch in the Start or
On positions, the indicator will be illuminated. The
seatbelt indicator remains illuminated until the seat
belt switch sense input to the cluster is an open cir-
cuit (seatbelt switch opened - seatbelt buckled), or
until the ignition switch is turned to the Off position,
whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
The seatbelt switch input to the instrument cluster
circuitry can be diagnosed using conventional diag-
nostic tools and methods. For further diagnosis of the
seatbelt indicator or the instrument cluster circuitry
that controls the LED, (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING).
SERVICE REMINDER
INDICATOR
DESCRIPTION
A Service Reminder Indicator (SRI) is standard
equipment on all instrument clusters. However, on
vehicles not equipped with certain optional heavy
duty emission cycle gasoline engines, this indicator is
electronically disabled. The SRI is located near the
lower edge of the instrument cluster overlay, to the
left of center. The SRI consists of a stencilled cutout
of the words ªMAINT REQDº in the opaque layer of
the instrument cluster overlay. The dark outer layer
of the overlay prevents the indicator from being
clearly visible when it is not illuminated. An amber
lens behind the cutout in the opaque layer of the
overlay causes the ªMAINT REQDº text to appear in
amber through the translucent outer layer of the
overlay when the indicator is illuminated from
behind by a Light Emitting Diode (LED) soldered
onto the instrument cluster electronic circuit board.The SRI is serviced as a unit with the instrument
cluster.
OPERATION
The Service Reminder Indicator (SRI) gives an
indication to the vehicle operator when engine emis-
sions maintenance procedures should be performed.
This indicator is controlled by a transistor on the
instrument cluster circuit board based upon the clus-
ter programming and electronic messages received by
the cluster from the Powertrain Control Module
(PCM) over the Chrysler Collision Detection (CCD)
data bus. The SRI Light Emitting Diode (LED)
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (st-run) circuit whenever the ignition
switch is in the On or Start positions; therefore, the
LED will always be off when the ignition switch is in
any position except On or Start. The LED only illu-
minates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster
will turn on the SRI for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the SRI is illuminated for
about two seconds as a bulb test.
²Service Required Lamp-On Message- Each
time the cluster receives a service required lamp-on
message from the PCM indicating that an emissions
maintenance interval has been reached, the SRI will
be illuminated. The indicator remains illuminated
until the cluster receives a service required lamp-off
message from the PCM, or until the ignition switch
is turned to the Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the SRI will be turned on
during the bulb check portion of the test to confirm
the functionality of the LED and the cluster control
circuitry.
The PCM continually monitors the vehicle speed
sensor to determine the distance the vehicle has been
driven, then sends the proper messages to the instru-
ment cluster. Once the SRI has been illuminated and
the required emissions maintenance procedures have
been completed, the PCM must be reset using a
DRBIIItscan tool before it will send the proper ser-
vice required lamp-off message to the instrument
cluster. Refer to the appropriate diagnostic informa-
tion. For further diagnosis of the SRI or the instru-
ment cluster circuitry that controls the LED, (Refer
to 8 - ELECTRICAL/INSTRUMENT CLUSTER -
DIAGNOSIS AND TESTING). For proper diagnosis
of the PCM, the CCD data bus, or the message
inputs to the instrument cluster that control the SRI,
a DRBIIItscan tool is required. Refer to the appro-
priate diagnostic information.
8J - 28 INSTRUMENT CLUSTERBR/BE
SEATBELT INDICATOR (Continued)
Page 644 of 2889
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, this
system 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
will return to the last function being displayed before
the ignition was turned to the Off position. With the
ignition switch in the On position, momentarily
depressing and releasing the Step push button switch
will cause the compass-mini-trip computer to change
its mode of operation, and momentarily depressing
and releasing the U.S./Metric push button will cause
the unit to toggle between U.S. and Metric measure-
ments. While in either compass mode, depressing the
U.S./Metric push button for more than ten seconds
will toggle the display between the compass/temper-
ature and the compass/compass in degrees modes.
This compass mini-trip computer features several
functions that can be reset. If both the Step and U.S./
Metric push buttons are depressed at the same time
with the ignition switch in the On position, the trip
computer information that can be reset is reset.
Depressing and releasing the Step and U.S./Metric
push buttons at the same time for more than 100
milliseconds, but not more than one second while in
any display mode (except the compass/temperature
mode) will cause a local reset. A local reset affects
only the function currently displayed. See the Reset
Chart below for more information on this feature.
Performing a local reset while in the compass/tem-
perature mode enters the module into the compass
variance setting mode.
Depressing and releasing the Step and U.S./Metric
push buttons at the same time for more than two
seconds while in any display mode (except the com-
pass/temperature mode) will cause a global reset. A
global reset changes all of the trip computer func-
tions that can be reset.
For more information on the features and control
functions of the compass mini-trip computer, see the
owner's manual in the vehicle glove box.
BR/BEMESSAGE SYSTEMS 8M - 9
COMPASS/MINI-TRIP COMPUTER (Continued)
Page 665 of 2889
DRIVER POWER SEAT SWITCH
DESCRIPTION
The power seat in standard cab models can be
adjusted in six different ways using the power seat
switches (Fig. 1). The power seat switch for extended
cab models (club cab and quad cab) has an additional
switch knob for adjusting the power lumbar support.
The switch is located on the lower outboard side of the
seat cushion on the seat cushion side shield on all mod-
els. Refer to the owner's manual in the vehicle glove box
for more information on the power seat switch functions
and the seat adjusting procedures.
The individual switches in the power seat switch
module cannot be repaired. If one switch is damaged
or faulty, the entire power seat switch module must
be replaced.
OPERATION
When a power switch control knob or knobs are actu-
ated, a battery feed and a ground path are applied
through the switch contacts to the power seat track or
recliner adjuster motor. The selected adjuster motor
operates to move the seat track or recliner through its
drive unit in the selected direction 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 adjuster motor to run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel limit.
The power seat adjuster motors each contain a self-re-
setting circuit breaker to protect them from overload.
However, consecutive or frequent resetting of the circuit
breaker must not be allowed to continue, or the motor
may be damaged.
DIAGNOSIS & TESTING - DRIVER POWER
SEAT SWITCH
For circuit descriptions and diagrams, refer to Wir-
ing Diagrams.
(1)
Disconnect and isolate the battery negative cable.
(2)Remove the power seat switch from the power
seat.
(3)Use an ohmmeter to test the continuity of the
power seat switches in each position. See the Power
Seat Switch Continuity chart (Fig. 2) . If OK, see Power
Seat Adjuster and Motors or Power Lumbar Adjuster
and Motor in the Diagnosis and Testing section of this
group. If not OK, replace the faulty power seat switch
unit.
DRIVER POWER SEAT SWITCH TEST TABLE
DRIVER SWITCH
POSITIONCONTINUITY BETWEEN
OFF B-N, B-J, B-M
B-E, B-L, B-K
VERTICAL UP A-E, A-M, B-N, B-E
VERTICAL DOWN A-J, A-N, B-M, B-E
HORIZONTAL
FORWARDA-L, B-K
HORIZONTAL
REARWARDA-K, B-L
FRONT TILT UP A-M, B-N
FRONT TILT DOWN A-N, B-M
REAR TILT UP A-E, B-J
REAR TILT DOWN A-J, B-E
LUMBAR OFF O-P, O-R, P-R
LUMPAR UP (INFLATE) O-P, Q-R
LUMBAR DOWN
(DEFLATE)O-R, P-Q
Fig. 1 Seat Switches and Bezel - Standard Cab
1 - Seat Switch
Fig. 2 Testing Driver Power Seat Switch
8N - 16 POWER SEAT SYSTEMBR/BE
Page 667 of 2889
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 8-way power 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 toBucket Seat Back
in Body for the seat back frame service procedures.
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 & TESTING - POWER LUMBAR
ADJUSTER
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 toPower Lumbar Switch
in the Diagnosis and Testing section of this group. If
the power lumbar adjuster fails to operate in either
direction, perform the following tests. For complete
circuit diagrams, refer toPower Seatin Wiring Dia-
grams.
(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. Refer toPower
Lumbar Switchin the Diagnosis and Testing sec-
tion of this group. If the switch tests OK, test the cir-
cuits of the power seat wire harness 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 har-
ness as required.
8N - 18 POWER SEAT SYSTEMBR/BE
LUMBAR CONTROL SWITCH (Continued)
Page 668 of 2889
PASSENGER POWER SEAT
SWITCH
DESCRIPTION
The power seat in standard cab models can be
adjusted in six different ways using the power seat
switches (Fig. 6). The power seat switch for extended
cab models (club cab and quad cab) has an additional
switch knob for adjusting the power lumbar support.
The switch is located on the lower outboard side of
the seat cushion on the seat cushion side shield on
all models. Refer to the owner's manual in the vehi-
cle glove box for more information on the power seat
switch functions and the seat adjusting procedures.
The individual switches in the power seat switch mod-
ule cannot be repaired. If one switch is damaged or
faulty, the entire power seat switch module must be
replaced.
OPERATION
When a power switch control knob or knobs are actu-
ated, a battery feed and a ground path are applied
through the switch contacts to the power seat track or
recliner adjuster motor. The selected adjuster motor
operates to move the seat track or recliner through its
drive unit in the selected direction until the switch is
released, or until the travel limit of the adjuster is
reached. When the switch is moved in the opposite direc-
tion, the battery feed and ground path to the motor are
reversed through the switch contacts. This causes the
adjuster motor to run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel
limit. The power seat adjuster motors each contain a
self-resetting circuit breaker to protect them from
overload. However, consecutive or frequent resettingof the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
DIAGNOSIS & TESTING - PASSENGER POWER
SEAT SWITCH
For circuit descriptions and diagrams, refer to Wir-
ing Diagrams.
(1)
Disconnect and isolate the battery negative cable.
(2)Remove the power seat switch from the power
seat.
(3) Use an ohmmeter to test the continuity of the
power seat switches in each position. See the Power
Seat Switch Continuity chart below (Fig. 7) . If OK,
see Power Seat Adjuster and Motors or Power Lum-
bar Adjuster and Motor in the Diagnosis and Testing
section of this group. If not OK, replace the faulty
power seat switch unit.
PASSENGER POWER SEAT SWITCH TEST TABLE
PASSENGER SWITCH
POSITIONCONTINUITY BETWEEN
OFF B-N, B-J, B-M,B-E, B-L,
B-K
VERTICAL DOWN A-E, A-M, B-N, B-E
VERTICAL UP A-J, A-N, B-M, B-E
HORIZONTAL
FORWARDA-L, B-K
HORIZONTAL
REARWARDA-K, B-L
FRONT TILT DOWN A-M, B-N
FRONT TILT UP A-N, B-M
REAR TILT DOWN A-E, B-J
REAR TILT UP A-J, B-E
LUMBAR OFF O-P, O-R, P-R
LUMBAR DOWN
(DEFLATE)O-P, Q-R
LUMBAR UP (INFLATE) O-R, P-Q
Fig. 6 Seat Switches and Bezel - Standard Cab
1 - Seat Switch
Fig. 7 Testing Passenger Power Seat Switch
BR/BEPOWER SEAT SYSTEM 8N - 19
Page 670 of 2889
the motor and drive unit of the power seat recliner
mechanism is secured with two screws to the seat
cushion frame, and is concealed by the outboard seat
cushion side shield.
The power seat recliner cannot be repaired. If the
unit is faulty or damaged, it must be replaced. Refer
toBucket Seat Reclinerin Body for the service
procedure.
OPERATION
The power seat recliner includes a reversible elec-
tric motor that is secured to the lower hinge plate of
the recliner unit. The motor is connected to a gearbox
that moves the upper hinge plate of the power seat
recliner through a screw-type drive unit.
DIAGNOSIS & TESTING - POWER SEAT
RECLINER
Following are tests that will help to diagnose the
hard wired components and circuits of the power seat
system. Actuate the power seat recliner switch to
move the power seat recliner adjuster in each direc-
tion. The power seat recliner adjuster should move in
both directions. If the power seat recliner adjuster
fails to operate 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 seat recliner adjuster
still fails to operate in only one direction, refer to
Power Seat Switchin the Diagnosis and Testing
section of this group. If the power recliner adjuster
fails to operate in either direction, perform the fol-
lowing tests. For complete circuit diagrams, refer to
Power Seatin 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 seat switch connector recepta-
cle. Check for battery voltage at the fused B(+)
circuit cavity of the power seat wire harness connec-
tor for the power seat 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 seat 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 seat switch. Refer toPower
Seat Switchin the Diagnosis and Testing section of
this group. If the switch tests OK, test the circuits of
the power seat wire harness between the power seat
recliner adjuster motor and the power seat switch for
shorts or opens. If the circuits check OK, replace the
faulty power seat recliner unit. If the circuits are not
OK, repair the power seat wire harness as required.
POWER SEAT TRACK
DESCRIPTION
There are three reversible motors that operate the
power seat adjuster. The motors are connected to
worm-drive gearboxes that move the seat adjuster
through a combination of screw-type drive units.
The front and rear of a seat are operated by differ-
ent motors. They can be raised or lowered indepen-
dently of each other. When the center seat switch is
pushed in the Up or Down direction, both the front
and rear motors operate in unison. On standard cab
models the entire seat is moved up or down, on
extended cab models (club cab and quad cab) the seat
cushion moves independently of the seat back in the
up or down directions. The forward-rearward motor
is operated by pushing the center seat switch in the
Forward or Rearward direction, which moves the
entire seat in the selected direction on all models.
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. Make
the necessary repairs.
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
switch contacts to the motor(s). The motor(s) and
drive unit(s) operate to move the seat in the selected
direction until the switch is released, or until the
travel limit of the power seat adjuster is reached.
When the switch is moved in the opposite direction,
the battery feed and ground path to the motor(s) are
reversed through the switch contacts. This causes the
motor to run in the opposite direction.
DIAGNOSIS & TESTING - POWER SEAT TRACK
For circuit descriptions and diagrams, refer to Wir-
ing Diagrams.
BR/BEPOWER SEAT SYSTEM 8N - 21
RECLINER MOTOR (Continued)
Page 675 of 2889
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 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)
Page 737 of 2889
WIPER MODULE
DESCRIPTION
The wiper module is secured with screws to the
cowl plenum panel and concealed within the cowl
plenum area beneath the cowl plenum cover/grille
panel. The ends of the wiper pivot shafts that pro-
trude through dedicated openings in the cowl plenum
cover/grille panel to drive the wiper arms and blades
are the only visible components of the wiper module.
The wiper module consists of the following major
components:
²Bracket- The wiper module bracket consists of
a long tubular steel main member that has a
stamped pivot bracket formation near each end
where the two wiper pivots are secured. A stamped
steel mounting plate for the wiper motor is secured
with welds near the center of the main member.
²Crank Arm- The wiper motor crank arm is a
stamped steel unit that has a slotted hole on the
driven end that is secured to the wiper motor output
shaft with a nut, and has a ball stud secured to the
drive end.
²Linkage- The two wiper linkage members are
each constructed of stamped steel. A driver side drive
link with a plastic socket-type bushing in the left
end, and a plastic sleeve-type bushing in the right
end. Socket bushing is snap-fit over the pivot ball
stud on the left pivot, while the sleeve bushing is fit
over the longer wiper motor crank arm pivot stud.
The passenger side drive link has a plastic socket-
type bushing on each end. One end of this drive link
is snap-fit over the pivot ball stud on the right pivot,
while the other end is snap-fit over the exposed end
of the longer ball stud on the wiper motor crank arm.
²Motor- The wiper motor is secured with three
screws to the motor mounting plate near the center
of the wiper module bracket. The wiper motor output
shaft passes through a hole in the module bracket,
where a nut secures the wiper motor crank arm to
the motor output shaft. The two-speed permanent
magnet wiper motor features an integral transmis-
sion, an internal park switch, and an internal Posi-
tive Temperature Coefficient (PTC) circuit breaker.
²Pivots- The two wiper pivots are secured to the
ends of the wiper module bracket. The crank arms
that extend from the bottom of the pivot shafts each
have a ball stud on their end. The upper end of each
pivot shaft where the wiper arms will be fastened
each has an externally serrated drum secured to it.
The wiper module cannot be adjusted or repaired.
If any component of the module is faulty or damaged,
the entire wiper module unit must be replaced.
OPERATION
The wiper module operation is controlled by the
vehicle operator through battery current inputs
received by the wiper motor from the multi-function
switch on the steering column. The wiper motor
speed is controlled by current flow to either the low
speed or the high speed set of brushes. The park
switch is a single pole, single throw, momentary
switch within the wiper motor that is mechanically
actuated by the wiper motor transmission compo-
nents. The park switch alternately closes the wiper
park switch sense circuit to ground or to battery cur-
rent, depending upon the position of the wipers on
the glass. This feature allows the motor to complete
its current wipe cycle after the wiper system has
been turned Off, and to park the wiper blades in the
lowest portion of the wipe pattern. The automatic
resetting circuit breaker protects the motor from
overloads. The wiper motor crank arm, the two wiper
linkage members, and the two wiper pivots mechan-
ically convert the rotary output of the wiper motor to
the back and forth wiping motion of the wiper arms
and blades on the glass.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the wiper arms from the wiper pivots.
(Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARMS - REMOVAL).
(3) Remove the cowl plenum cover/grille panel
from the cowl plenum. (Refer to 23 - BODY/EXTERI-
OR/COWL GRILLE - REMOVAL).
(4) Remove the four screws that secure the wiper
module bracket to the cowl plenum panel and the
dash panel (Fig. 8).
(5) Reach into the cowl plenum to move the wiper
module far enough to access the wiper module elec-
trical connections (Fig. 9).
Fig. 8 Wiper Module Remove/Install
1 - WIPER MODULE MOUNTING SCREWS
8R - 14 WIPERS/WASHERSBR/BE