
OPERATION - POWER LOCK SYSTEM
All versions of the power lock system allow both
doors to be locked or unlocked electrically by operat-
ing the power lock switch on either front door trim
panel. On vehicles that are also equipped with the
optional Remote Keyless Entry (RKE) system, both
doors may also be locked or unlocked using a key in
either front door lock cylinder, or by using the RKE
transmitter. On vehicles with the RKE system, if cer-
tain features have been electronically enabled, the
locks may also be operated automatically by the
high-line or premium Central Timer Module (CTM)
based upon various other inputs. Those features and
their inputs are:
²Automatic Door Lock- If enabled, the high-
line/premium CTM will automatically lock the doors
when it receives a message from the Powertrain Con-
trol Module (PCM) indicating that the vehicle speed
is about 24 kilometers-per-hour (15 miles-per-hour)
or greater. The CTM also monitors the door ajar
switches, and will not activate the automatic door
lock feature until both doors have been closed for at
least five seconds. If this feature is enabled and a
door is opened after the vehicle is moving, the CTM
will also lock the doors five seconds after both doors
are closed.
²Central Locking- Vehicles equipped with a
high-line/premium CTM also have a resistor-multi-
plexed door cylinder lock switch mounted to the back
of the door lock cylinder within each front door. The
CTM continually monitors the input from these
switches to provide the central locking/unlocking fea-
ture. The CTM will automatically lock or unlock both
front doors when either front door is locked or
unlocked using a key.
²Door Lock Inhibit- The high-line/premium
CTM receives inputs from the key-in ignition switch,
the headlamp switch, and the door ajar switches. The
logic within the CTM allows it to monitor these
inputs to provide a door lock inhibit feature. The
door lock inhibit feature prevents the power lock sys-
tem from being energized with a power lock switch
input if the driver door is open with the headlamps
on or the key still in the ignition switch. However,
the locks can still be operated with the manual door
lock button or with a key in the door lock cylinder,
and the power locks will still operate using the RKE
transmitter while the driver door is open with the
headlamps on or a key in the ignition.
²Enhanced Accident Response- If enabled,
the high-line/premium CTM provides an enhanced
accident response feature. This feature uses elec-
tronic message inputs received by the CTM from the
Airbag Control Module (ACM) to determine when an
airbag has been deployed. The CTM also monitors
the state of the power lock system and the vehiclespeed messages from the PCM in order to provide
this feature. If the airbag has been deployed and the
vehicle has stopped moving, the CTM will automati-
cally unlock the doors, prevent the doors from being
locked, and turn on the courtesy lamps inside the
vehicle. Of course, these responses are dependent
upon a functional battery and electrical circuitry fol-
lowing the impact.
All versions of the power lock system operate on
battery current received through a fused B(+) circuit
from a fuse in the Junction Block (JB) so that the
system remains functional, regardless of the ignition
switch position. Also, in both versions of the power
lock system, each power lock switch receives battery
current independent of the other. In vehicles with the
base version of the power lock system, the driver side
power lock switch receives ground through the body
wire harness. A single wire take out of the body wire
harness with an eyelet terminal connector is secured
by a ground screw to the lower left B-pillar (regular
cab, extended cab) or lower left quarter inner panel
(quad cab). The passenger side power lock switch
receives ground through the driver side power lock
switch in the base version of the power lock system.
The base version power lock switches direct the
appropriate battery current and ground feeds to the
power lock motors. In the power lock system for vehi-
cles with the RKE system, the power lock switches
direct a battery current Lock or Unlock request sig-
nal to the high-line or premium CTM, and the CTM
energizes internal relays to direct the appropriate
battery current and ground feeds to the power lock
motors.
OPERATION - REMOTE KEYLESS ENTRY
SYSTEM
On vehicles with the Remote Keyless Entry (RKE)
system, the power locks can be operated remotely
using the RKE transmitter. If the vehicle is so
equipped, the RKE transmitter also arms and dis-
arms the factory-installed Vehicle Theft Security Sys-
tem (VTSS). Three small, recessed buttons on the
outside of the transmitter case labelled Lock, Unlock,
and Panic allow the user to choose the function that
is desired. The RKE transmitter then sends the
appropriate Radio Frequency (RF) signal. An RF
receiver that is integral to the high-line or premium
version of the Central Timer Module (CTM) receives
the transmitted signal, then uses its internal elec-
tronic programming to determine whether the
received signal is valid and what function has been
requested. If the signal is valid, the CTM provides
the programmed features.
Besides operating the power lock system and arm-
ing or disarming the VTSS, the RKE system also
controls the following features:
BR/BEPOWER LOCKS 8N - 3
POWER LOCKS (Continued)

and receiving the proper messages on the CCD data
bus, that the CTM is receiving the proper hard wired
inputs, and that the power lock motors are being sent
the proper hard wired outputs by the CTM.
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.
PRELIMINARY TESTS
To begin this test, note the system operation while
you actuate both the Lock and Unlock functions with
the power lock switches, the door cylinder lock switches,
and the RKE transmitter. Then, proceed as follows:
²If the entire power lock system fails to function
with the power lock switches, the door cylinder lock
switches, or the RKE transmitter, check the fused
B(+) fuse in the Junction Block (JB). If the fuse is
OK, proceed to the diagnosis of the power lock
motors. (Refer to 8 - ELECTRICAL/POWER LOCKS/
POWER LOCK MOTOR - DIAGNOSIS AND TEST-
ING).
²If the power lock system functions with both
power lock switches, and both door cylinder lock
switches, but not with the RKE transmitter, proceed
to the diagnosis of the transmitter. (Refer to 8 -
ELECTRICAL/POWER LOCKS/REMOTE KEYLESS
ENTRY TRANSMITTER - DIAGNOSIS AND TEST-
ING).
²
If the entire power lock system functions with the
RKE transmitter, and both door cylinder lock switches,
but not with one or both of the power lock switches, pro-
ceed to diagnosis of the power lock switches. (Refer to 8
- ELECTRICAL/POWER LOCKS/POWER LOCK
SWITCH - DIAGNOSIS AND TESTING).
²If the entire power lock system functions with
the RKE transmitter, and both power lock switches,
but not with one or both of the door cylinder lock
switches, proceed to diagnosis of the door cylinder
lock switches. (Refer to 8 - ELECTRICAL/POWER
LOCKS/DOOR CYLINDER LOCK SWITCH - DIAG-
NOSIS AND TESTING).
²If one power lock motor fails to operate with
both of the power lock switches, both of the door cyl-
inder lock switches and/or the RKE transmitter, pro-
ceed to diagnosis of the power lock motor. (Refer to 8
- ELECTRICAL/POWER LOCKS/POWER LOCK
MOTOR - DIAGNOSIS AND TESTING).
If the problem being diagnosed is related to one or
more of the electronic features (automatic locks, door
lock inhibit, enhanced accident response, illuminated
entry, panic mode, or RKE horn chirp), further diag-
nosis should be performed using a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
DOOR CYLINDER LOCK
SWITCH
DESCRIPTION
A door cylinder lock switch is snapped onto the
back of the key lock cylinder inside each front door of
vehicles equipped with a high-line or premium Cen-
tral Timer Module (CTM). The door cylinder lock
switch is a resistor multiplexed momentary switch
that is hard wired in series between a body ground
and the CTM through the front door wire harness.
The door cylinder lock switches are driven by the key
lock cylinders and contain three internal resistors.
One resistor is used for the neutral switch position,
one for the Lock position, and one for the Unlock
position.
The door cylinder lock switches cannot be adjusted
or repaired and, if faulty or damaged, they must be
replaced.
OPERATION
The door cylinder lock switches are actuated by the
key lock cylinder when the key is inserted in the lock
cylinder and turned to the lock or unlock positions.
The door cylinder lock switch closes a path to ground
through one of three internal resistors for the Cen-
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 & 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.
BR/BEPOWER LOCKS 8N - 5
POWER LOCKS (Continued)

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.
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.
Fig. 1 Door Cylinder Lock Switch
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)

REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the
automatic day/night mirror (Fig. 2).
(3) Remove the set screw that secures the auto-
matic day/night mirror to the windshield support
button.
(4) Push the automatic day/night mirror upwards
far enough for the mounting bracket to clear the sup-
port button and remove the mirror from the wind-
shield.
INSTALLATION
(1) Install the mirror to the support button.
(2) Tighten the set screw.
(3) Reconnect the harness connector to the mirror.
(4) Reconnect the negative battery cable.
POWER MIRROR SWITCH
DESCRIPTION
Both the right and left power outside mirrors are
controlled by a single multi-function switch unit
located on and mounted to the upper flag area of the
driver side door trim panel.
OPERATION
The switch knob is rotated clockwise (right mirror
control), or counterclockwise (left mirror control) to
select the mirror to be adjusted. The switch knob is
then moved in a joystick fashion to control movement
of the selected mirror up, down, right, or left.
The power mirror switch cannot be repaired and, if
faulty or damaged, it must be replaced. The power
mirror switch knob is available for service replace-
ment.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Pull the control knob rearward to remove it
from the power mirror switch stem (Fig. 3).
Fig. 2 AUTOMATIC DAY/NIGHT MIRROR REMOVE
1 - SCREW
2 - WIRE HARNESS CONNECTOR
3 - AUTOMATIC DAY/NIGHT MIRROR
4 - SUPPORT BUTTON
Fig. 3 POWER MIRROR SWITCH REMOVE/INSTALL
1 - DOOR
2 - SWITCH
3 - DOOR TRIM PANEL
4 - KNOB
5 - NUT
8N - 12 POWER MIRRORSBR/BE
AUTOMATIC DAY / NIGHT MIRROR (Continued)

(3) Remove the nut that secures the power mirror
switch to the driver side front door trim panel.
(4) Remove the trim panel from the inside of the
driver side front door. (Refer to 23 - BODY/DOOR -
FRONT/TRIM PANEL - REMOVAL) for the proce-
dures.
(5) Pull the trim panel away from the inner door
far enough to access the power mirror switch wire
harness connector.
(6) Unplug the power mirror switch wire harness
connector.
(7) Remove the power mirror switch from the back
of the door trim panel.
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.
BR/BEPOWER MIRRORS 8N - 13
POWER MIRROR SWITCH (Continued)

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

REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) If equipped with a 6-way power seat, remove
the two screws that secure the power seat switch and
bezel unit to the seat cushion frame (Fig. 3).
(3) If equipped with a 8-way power seat, remove
the seat cushion side shield from the seat. Refer to
Body for the procedure.
(4) Pull the switch bezel or side shield unit out
from the seat far enough to access the switch wire
harness connector. Gently pry the locking tabs of the
switch away from the wire harness connector and
carefully unplug the connector from the power seat
switch module (Fig. 4).
(5) Remove the screws that secure the power seat
switch (Fig. 5).
INSTALLATION
(1) Position the power seat switch on the seat
cushion side shield and connect the electrical connec-
tor.
(2) Install the screws that secure the power seat
switch to seat cushion side shield.
(3) Install the seat cushion side shield on the seat.
Refer to Body for the procedure.
(4) If equipped, install the recliner lever on the
recliner mechanism release shaft.
(5) If equipped, install the screw that secures the
recliner lever to the recliner mechanism release shaft
on the outboard side of the front seat.
(6) Connect the battery negative cable.
LUMBAR CONTROL SWITCH
DESCRIPTION
The 8-way power seat option includes an electri-
cally operated lumbar support mechanism. A single
two-way momentary power lumbar switch is integral
with the power seat switches. The power lumbar
switch is secured to the back of the seat cushion side
shield with screws, and the switch paddle protrudes
through a hole to the outside of the shield. The
switch paddle is located in a shallow depression
molded into the outer surface of the seat cushion side
shield that helps to shroud it from unintentional
actuation when entering or leaving the vehicle.
The power lumbar switches cannot be adjusted or
repaired and, if faulty or damaged, the seat switch
assembly must be replaced.
Fig. 3 Seat Switches and Bezel - Standard Cab
1 - Seat Switch
Fig. 4 Power Seat Switch Connector Remove -
Standard Cab
1 - Release Tabs (3)
Fig. 5 Power Seat Switch Remove/Install - Extended
Cab
1 - Seat Cushion Side Shield
2 - Power Seat Switch
3 - Retaining Screws
BR/BEPOWER SEAT SYSTEM 8N - 17
DRIVER POWER SEAT SWITCH (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 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)