tral Timer Module (CTM) when the front door key
lock cylinder is in the Lock, Unlock, or Neutral posi-
tions. The CTM reads the switch status through an
internal pull-up, then uses this information as an
input for both power lock system and Vehicle Theft
Security System (VTSS) operation.
The door cylinder lock switches and circuits can be
diagnosed using conventional diagnostic tools and
methods.
DIAGNOSIS AND TESTING - DOOR CYLINDER
LOCK SWITCH
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.
(1) Disconnect the door cylinder lock switch pigtail
wire connector from the door wire harness connector.
(2) Using an ohmmeter, perform the switch resis-
tance checks between the two cavities of the door cyl-
inder lock switch pigtail wire connector. Actuate the
switch by rotating the key in the door lock cylinder
to test for the proper resistance values in each of the
three switch positions, as shown in the Door Cylinder
Lock Switch chart.
DOOR CYLINDER LOCK SWITCH
Switch Position
Resistance
Driver Side Passenger Side
Neutral Neutral 12 Kilohms
Lock (Clockwise)Lock (Counter
Clockwise)644 Ohms
Unlock (Counter
Clockwise)Unlock
(Clockwise)1565 Ohms
(3) If a door cylinder lock switch fails any of the
resistance tests, replace the faulty switch as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the door outside latch handle mount-
ing hardware and linkage from the inside of the door.
(Refer to 23 - BODY/DOOR - FRONT/EXTERIOR
HANDLE - REMOVAL).
(3) From the outside of the door, pull the door out-
side latch handle out from the door far enough to
access the door cylinder lock switch (Fig. 1).
(4) Disengage the door cylinder lock switch from
the back of the lock cylinder.(5) Disconnect the door cylinder lock switch pigtail
wire connector from the door wire harness connector.
(6) Disengage the retainers that secure the door
cylinder lock switch pigtail wire harness to the inner
door panel.
(7) Remove the door cylinder lock switch from the
door.
INSTALLATION
(1) Position the door cylinder lock switch into the
door (Fig. 1).
(2) Engage the retainers that secure the door cyl-
inder lock switch pigtail wire harness to the inner
door panel.
(3) Reconnect the door cylinder lock switch pigtail
wire connector to the door wire harness connector.
(4) Reinstall the door cylinder lock switch onto the
back of the lock cylinder.
(5) Reinstall the door outside latch handle mount-
ing hardware and linkage on the inside of the door.
(Refer to 23 - BODY/DOOR - FRONT/EXTERIOR
HANDLE - INSTALLATION).
(6) Reconnect the battery negative cable.
Fig. 1 Door Cylinder Lock Switch - Typical
1 - DOOR OUTSIDE LATCH HANDLE
2 - DOOR
3 - DOOR CYLINDER LOCK SWITCH
4 - CONNECTOR
5 - RETAINERS
8N - 6 POWER LOCKSBR/BE
DOOR CYLINDER LOCK SWITCH (Continued)
POWER LOCK MOTOR
DESCRIPTION
Models equipped with the optional power lock sys-
tem have a power operated door locking mechanism
located within each front door. The lock mechanisms
are actuated by a reversible electric power lock motor
that is integral to the door latch unit within each
front door. A single short pigtail wire with a molded
plastic connector insulator connects the door lock
motor to the vehicle electrical system through a take
out and connector of each front door wire harness.
The power lock motors cannot be adjusted or
repaired and, if faulty or damaged, the entire door
latch unit must be replaced.
OPERATION
On models with a base version of the Central
Timer Module (CTM), the power lock motor is con-
trolled by the battery and ground feeds from the
power lock switches. On models with the high-line or
premium versions of the CTM, the power lock motor
is controlled by the battery and ground feeds from
the power lock and unlock relays, which are integral
and internal to the high-line and premium versions
of the CTM. A positive and negative battery connec-
tion to the two motor terminals will cause the power
lock motor plunger to move in one direction. Revers-
ing the current through these same two connections
will cause the power lock motor plunger to move in
the opposite direction.
The power lock motors and circuits can be tested
using conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - POWER LOCK
MOTOR
On models with a base version of the Central
Timer Module (CTM), confirm proper power lock
switch operation before you proceed with this diagno-
sis. On models with a high-line or premium version
of the CTM, confirm proper power lock switch, power
lock switch output circuit, and CTM operation before
you proceed with this diagnosis. Remember, the
power lock switch controls the output to the power
lock motors on models with a base CTM, while the
CTM controls the output to the power lock motors on
models with a high-line or premium CTM. Refer to
the appropriate wiring information. The wiring infor-
mation 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 con-
nectors, splices and grounds.
(1) Check each power lock motor for correct opera-
tion while moving the power lock switch to both theLock and Unlock positions. If both of the power lock
motors are inoperative, go to Step 2. If one power
lock motor is inoperative, go to Step 3.
(2) If both of the power lock motors are inopera-
tive, the problem may be caused by one shorted
motor. Disconnecting a shorted power lock motor
from the power lock circuit will allow the good power
lock motors to operate. Disconnect the wire harness
connector from each power lock motor, one at a time,
and recheck both the lock and unlock functions by
operating the power lock switch. If both power lock
motors are still inoperative after the above test,
check for a short or open circuit between the power
lock motors and either the power lock switch (base
CTM) or the CTM (high-line or premium CTM). If
disconnecting one power lock motor causes the other
motor to become functional, go to Step 3 to test the
disconnected motor.
(3) Once it is determined which power lock motor
is inoperative, that motor can be tested as follows.
Disconnect the door wire harness connector from the
inoperative power lock motor. Apply 12 volts to the
lock and unlock driver circuit cavities of the power
lock motor pigtail wire connector to check its opera-
tion in one direction. Reverse the polarity to check
the motor operation in the opposite direction. If OK,
repair the shorted or open circuits between the power
lock motor and the power lock switch (base CTM) or
the CTM (high-line or premium CTM) as required. If
not OK, replace the faulty power lock motor.
REMOTE KEYLESS ENTRY
TRANSMITTER
DESCRIPTION
The Remote Keyless Entry (RKE) system Radio
Frequency (RF) transmitter is equipped with three
buttons, labeled Lock, Unlock, and Panic. It is also
equipped with a key ring and is designed to serve as
a key fob. The operating range of the transmitter
radio signal is up to 7 meters (23 feet) from the RKE
receiver. The RKE receiver is integral to the high-
line or premium Central Timer Module (CTM) in this
vehicle.
Each RKE transmitter has a different vehicle
access code, which must be programmed into the
memory of the RKE receiver in the vehicle in order
to operate the RKE system. The RKE receiver can
retain the access codes for up to four transmitters in
its memory. (Refer to 8 - ELECTRICAL/POWER
LOCKS/REMOTE KEYLESS ENTRY TRANSMIT-
TER - STANDARD PROCEDURE - RKE TRANS-
MITTER PROGRAMMING).
BR/BEPOWER LOCKS 8N - 7
DIAGNOSIS AND TESTING - POWER LOCK
SWITCH
The Light-Emitting Diode (LED) illumination
lamps for all of the power window and lock switch
and bezel unit switch paddles receive battery current
through the power window circuit breaker in the
Junction Block (JB). If all of the LEDs are inopera-
tive in either or both power window and lock switch
and bezel units, be certain to diagnose the power
window system before replacing the switch unit.
(Refer to 8 - ELECTRICAL/POWER WINDOWS -
DIAGNOSIS AND TESTING). If only one LED in a
power window and lock switch and bezel unit is inop-
erative, replace the faulty switch and bezel unit.
Refer to the appropriate wiring information. The wir-
ing 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.
(1) Check the fused B(+) fuse (Fuse 13 - 10
ampere) in the Junction Block (JB). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
(Fuse 13 - 10 ampere) in the JB. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit between
the JB and the Power Distribution Center (PDC) as
required.
(3) Disconnect and isolate the battery negative
cable. Remove the power window and lock switch and
bezel unit from the door trim panel. Disconnect the
door wire harness connector for the power window
and lock switch unit from the switch connector recep-
tacle.
(4) Reconnect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
door wire harness connector for the power window
and lock switch unit. If OK, go to Step 5. If not OK,
repair the open fused B(+) circuit between the power
window and lock switch unit and the JB as required.(5) Test the power lock switch continuity. See the
Power Lock Switch Continuity charts to determine if
the continuity is correct in the Neutral, Lock, and
Unlock switch positions (Fig. 2) or (Fig. 3). If OK,
repair the door lock switch output (lock and/or
unlock) circuit(s) between the power window and lock
switch unit and the power lock motors (base Central
Timer Module [CTM]) or the CTM (high-line or pre-
mium CTM) as required. If not OK, replace the
faulty power window and lock switch and bezel unit.
DRIVER SIDE LOCK SWITCH
SWITCH POSITION CONTINUITY BETWEEN
NEUTRAL 7 & 9,8&9
LOCK 7 & 9,8&10
UNLOCK 7 & 10,8&9
LAMP 3 & 5
Fig. 2 Power Lock Switch Continuity - Driver Side
1 - VIEW OF SWITCH CONNECTOR RECEPTACLE
BR/BEPOWER LOCKS 8N - 9
POWER LOCK SWITCH (Continued)
OPERATION
The ambient photocell sensor is located on the for-
ward-facing (windshield side) of the rear view mirror
housing, and detects the ambient light levels outside
of the vehicle. The headlamp photocell sensor is
located inside the rear view mirror housing behind
the mirror glass and faces rearward, to detect the
level of the light being received at the rear window
side of the mirror. When the circuitry of the auto-
matic day/night mirror detects that the difference
between the two light levels is too great (the light
level received at the rear of the mirror is much
higher than that at the front of the mirror), it begins
to darken the mirror.
The automatic day/night mirror circuitry also mon-
itors the transmission using an input from the
backup lamp circuit. The mirror circuitry is pro-
grammed to automatically disable its self-dimming
feature whenever it senses that the transmission
backup lamp circuit is energized.
The automatic day/night mirror is a completely
self-contained unit and cannot be repaired. If faulty
or damaged, the entire mirror assembly must be
replaced.
DIAGNOSIS AND TESTING - AUTOMATIC
DAY/NIGHT MIRROR
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.
(1) Check the fuse in the junction block. If OK, go
to Step 2. If not OK, repair the shorted circuit or
component as required replace the faulty fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fuse in the junction
block. If OK, go to Step 3. If not OK, repair the open
circuit to the ignition switch as required.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Unplug the wire harness connector from the auto-
matic day/night mirror (Fig. 1). Connect the battery
negative cable. Turn the ignition switch to the On
position. Check for battery voltage at the fused igni-
tion switch output (run/start) circuit cavity of the
automatic day/night mirror wire harness connector. If
OK, go to Step 4. If not OK, repair the open circuit to
the junction block as required.
(4) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Check for continuity between the ground circuit cav-ity of the automatic day/night mirror wire harness
connector and a good ground. There should be conti-
nuity. If OK, go to Step 5. If not OK, repair the cir-
cuit to ground as required.
(5) Connect the battery negative cable. Turn the
ignition switch to the On position. Set the parking
brake. Place the transmission gear selector lever in
the Reverse position. Check for battery voltage at the
backup lamp switch output circuit cavity of the auto-
matic day/night mirror wire harness connector. If
OK, go to Step 6. If not OK, repair the open circuit
as required.
(6) Turn the ignition switch to the Off position.
Disconnect the battery negative cable. Plug in the
automatic day/night mirror wire harness connector.
Connect the battery negative cable. Turn the ignition
switch to the On position. Place the transmission
gear selector lever in the Neutral position. Place the
mirror switch in the On (LED in the mirror switch is
lighted) position. Cover the forward facing ambient
photocell sensor to keep out any ambient light.
NOTE: The ambient photocell sensor must be cov-
ered completely, so that no light reaches the sen-
sor. Use a finger pressed tightly against the sensor,
or cover the sensor completely with electrical tape.
(7) Shine a light into the rearward facing head-
lamp photocell sensor. The mirror glass should
darken. If OK, go to Step 8. If not OK, replace the
faulty automatic day/night mirror unit.
(8) With the mirror glass darkened, place the
transmission gear selector lever in the Reverse posi-
tion. The mirror should return to its normal reflec-
tance. If not OK, replace the faulty automatic day/
night mirror unit.
Fig. 1 Automatic Day/Night Mirror
8N - 12 POWER MIRRORSBR/BE
AUTOMATIC DAY / NIGHT MIRROR (Continued)
INSTALLATION
(1) Insert the power mirror switch to the back of
the door trim panel.
(2) Connect the power mirror switch to the har-
ness connector.
(3) Install the trim panel to the inside of the
driver side door. (Refer to 23 - BODY/DOOR -
FRONT/TRIM PANEL - INSTALLATION).
(4) Install the nut that secures the power mirror
switch to the driver side front door.
(5) Push the control knob on to the power mirror
switch.
(6) Connect the battery negative cable.
SIDEVIEW MIRROR
DESCRIPTION
Each power mirror head contains two electric
motors, two drive mechanisms, and the mirror glass.
One motor and drive controls mirror up-and-down
movement, and the other controls right-and-left
movement.
OPERATION
The power mirrors in vehicles equipped with the
available heated mirror system option also include an
electric heating grid located behind the mirror glass.
This heating grid is energized by the heated mirror
relay in the heater and air conditioner control only
when the ignition switch is in the On position, and
the heated mirror system is turned on. (Refer to 8 -
ELECTRICAL/HEATED MIRRORS - DESCRIP-
TION) for more information.
The power mirror assembly cannot be repaired. If
any component of the power mirror unit is faulty or
damaged, the entire assembly must be replaced.
DIAGNOSIS AND TESTING - SIDEVIEW
MIRROR
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.
(1) Check the fuses in the Power Distribution Cen-
ter (PDC) and the junction block. If OK, go to Step 2.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse(s).(2) Check for battery voltage at the fuse in the
junction block. If OK, go to Step 3. If not OK, repair
the open circuit to the PDC as required.
(3) Disconnect and isolate the battery negative
cable. Remove the driver side door trim panel and
unplug the wire harness connector from the power
mirror switch. Connect the battery negative cable.
Check for battery voltage at the fused B(+) circuit
cavity in the door wire harness half of the power mir-
ror switch wire harness connector. If OK, go to Step
4. If not OK, repair the open circuit to the junction
block as required.
(4) Disconnect and isolate the battery negative
cable. Check for continuity between the ground cir-
cuit cavity in the door wire harness half of the power
mirror switch wire harness connector and a good
ground. There should be continuity. If OK, go to Step
5. If not OK, repair the circuit to ground as required.
(5) Check the power mirror switch continuity as
shown in (Fig. 4). If OK, go to Step 6. If not OK,
replace the faulty switch.
Fig. 4 Power Mirror Switch Continuity
MIRROR SELECTOR KNOB IN9L9POSITION
MOVE LEVER CONTINUITY BETWEEN
UP Pins 3 and 8, 1 and 7, 4 and 7
RIGHT Pins 3 and 7, 2 and 8, 5 and 8
DOWN Pins 3 and 7, 1 and 8, 4 and 8
LEFT Pins 3 and 8, 2 and 7, 5 and 7
MIRROR SELECTOR KNOB IN(R(POSITION
MOVE LEVER CONTINUITY BETWEEN
UP Pins 6 and 8, 1 and 7, 4 and 7
RIGHT Pins 6 and 7, 2 and 8, 4 and 8
DOWN Pins 6 and 7, 1 and 8, 4 and 8
LEFT Pins 6 and 8, 2 and 7, 5 and 7
8N - 14 POWER MIRRORSBR/BE
POWER MIRROR SWITCH (Continued)
POWER SEAT SYSTEM
TABLE OF CONTENTS
page page
POWER SEAT SYSTEM
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM............................16
DRIVER POWER SEAT SWITCH
DESCRIPTION.........................17
OPERATION...........................17
DIAGNOSIS AND TESTING - DRIVER POWER
SEAT SWITCH........................17
REMOVAL.............................18
INSTALLATION.........................18
LUMBAR CONTROL SWITCH
DESCRIPTION.........................18
OPERATION...........................19
REMOVAL.............................19
LUMBAR MOTOR
DESCRIPTION.........................19OPERATION...........................19
DIAGNOSIS AND TESTING - LUMBAR MOTOR . 19
PASSENGER POWER SEAT SWITCH
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING - PASSENGER
POWER SEAT SWITCH.................20
REMOVAL.............................21
INSTALLATION.........................21
POWER SEAT TRACK
DESCRIPTION.........................21
OPERATION...........................22
DIAGNOSIS AND TESTING - POWER SEAT
TRACK.............................22
REMOVAL.............................22
INSTALLATION.........................22
POWER SEAT SYSTEM
DESCRIPTION
The power seat system option allows the driver (or
passenger on SLT Plus with power seats) to electri-
cally adjust the seat position for optimum control and
comfort using the power seat switches located on the
outboard seat cushion side shield. The power seat
system allows the seating position to be adjusted for-
ward, rearward, front up, front down, rear up, or
rear down. The power seat system receives battery
current through a fuse in the Power Distribution
Center and a circuit breaker in the junction block,
regardless of the ignition switch position.
The quad cab models equipped with the power seat
option also feature a power operated lumbar support
in the seat back. The power lumbar support allows
the user to inflate or deflate a bladder located in the
lower seat back to achieve optimum comfort and sup-
port in the lower lumbar region of the spinal column.
The power lumbar support shares the battery feed
circuit of the power seat system.
The power seat system includes the power seat
adjuster and motors unit, the power lumbar support
bladder and electric pump (quad cab only), the power
seat switch, and the circuit breaker. Following are
general descriptions of the major components in the
power seat system. Refer toHeated Seat Systemfor information on the individually controlled heated
front seats. Refer to the owner's manual in the vehi-
cle glove box for more information on the features,
use and operation of the power seat system.
OPERATION
The power seat system allows the driver and/or
front passenger seating positions to be adjusted elec-
trically and independently using the separate power
seat switches found on the outboard seat cushion
side shield of each front seat. See the owner's manual
in the vehicle glove box for more information on the
features, use and operation of the power seat system.
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM
Before any testing of the power seat system is
attempted, the battery should be fully-charged and
all wire harness connections and pins cleaned and
tightened to ensure proper continuity and grounds.
For circuit descriptions and diagrams, refer to Wiring
Diagrams.
With the dome lamp on, apply the power seat
switch in the direction of the failure. If the dome
lamp dims, the seat may be jamming. Check under
and behind the seat for binding or obstructions. If
the dome lamp does not dim, proceed with testing of
the individual components and circuits.
8N - 16 POWER SEAT SYSTEMBR/BE
DRIVER POWER SEAT SWITCH
DESCRIPTION
The power seat in standard cab models can be
adjusted in eight different directions, up, down, front
up, front down, rear up, rear down, rearward and for-
ward. The power seat switch for quad cab models 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 (Fig. 1) on all models. 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
actuated, 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 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 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 resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
DIAGNOSIS AND TESTING - DRIVER POWER
SEAT SWITCH
The following procedure can be used to test the
power seat switch on standard and quad cab models.
Some quad cab trucks utilize a additional power lum-
bar option, if the switch being tested does not have
the lumbar option simply ignore the lumbar portion
of the test. For circuit descriptions and diagrams,
refer to Wiring 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 sec-
tion of this group. If not OK, replace the faulty power
seat switch unit.
Fig. 1 Power Seat Switch - Standard Cab
1 - SEAT SWITCH BEZEL
Fig. 2 Testing Driver Power Seat Switch
BR/BEPOWER SEAT SYSTEM 8N - 17
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)