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.
POWER LUMBAR ADJUSTER
DESCRIPTION
The ten-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, just forward of 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 (Fig. 1).
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 Bucket Seat Back
in the Removal and Installation section of Group 23 -
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 more
this grid is compressed, the more the slats bow out-
ward against the center of the seat back padding,
providing additional lumbar support.
POWER LUMBAR SWITCH
DESCRIPTION
The ten-way power seat option includes an electrically
operated lumbar support mechanism. A single two-way
momentary power lumbar switch is located on the out-
board seat cushion side shield of each front seat, just
forward of the other power seat switches. The power
lumbar switch is secured to the back of the seat cushion
side shield with two screws, and the switch paddle pro-
trudes 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, they must be
replaced.
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.
Fig. 1 Power Lumbar Adjuster
1 – SEAT BACK FRAME
2 – SEAT BACK PANEL
3 – SEAT WIRE HARNESS
4 – TIE WRAP
5 – SCREW (3)
6 – POWER LUMBAR ADJUSTER
7 – SEAT BACK TRIM COVER AND PADDING
8R - 2
POWER SEAT SYSTEMS
WJ
DESCRIPTION AND OPERATION (Continued)