Lumbar Support/Torso Bolster System Components
The lumbar support/torso bolster system for the driver and passenger consists
of the following components:
• | Driver and passenger lumbar support/torso bolster switches |
• | Driver and passenger lumbar support/torso bolster motor assemblies |
• | SEAT 30A circuit breaker |
Lumbar Support/Torso Bolster System Operation
The power lumbar support/torso bolster system is only available with the driver
memory, 8 way power seats option. The driver seat lumbar and torso adjuster motors
are controlled through the driver seat module, while the passenger seat lumbar and
torso adjuster motors are controlled directly through the lumbar support/torso bolster
adjuster switch.
The driver seat module supplies the driver seat lumbar support/torso bolster
adjuster switch assembly with a battery positive reference voltage. While the switches
are in an inactive state the switch contacts are closed to the switch ground circuit.
When a switch is pressed to an active state the switch contact is closed to the reference
voltage circuit. Battery voltage on a switch signal circuit indicates to the driver
seat module the switch status is active. Each seat adjuster motor is controlled by
the driver seat module through 2 motor control circuits. While the seat adjuster
motors are in an inactive state the motor control circuits are closed to ground circuit
contacts within the driver seat module. The driver seat module operates the seat
adjuster motors by switching one of a motor's control circuits to battery voltage.
The seat adjuster motors are bidirectional and the direction of adjuster motor rotation
is determined by which of the adjuster motor control circuits is switched to battery
voltage while the other remains grounded.
The seat adjuster motors are equipped with internal position sensors. The adjuster
motor position sensors are monitored by the driver seat module and are used to determine
the seat position when storing or recalling memory settings. The lumbar and torso
adjuster motors use hall effect type position sensors. The hall effect position sensors
are supplied with battery positive reference and ground circuits from the driver
seat module. The position sensor signal circuits are supplied battery positive voltage
through a resistor them monitored within the driver seat module. During adjuster
motor operation the hall effect position sensor provides a single pulse for every
revolution of the adjuster motor shaft. The driver seat module counts the pulses
from the position sensor signal circuits to determine the adjuster motor positions
when storing or recalling memory seat position settings.
Battery voltage is supplied to the passenger seat lumbar support/torso bolster
switch through the SEAT 30A circuit breaker. While the switches are in an inactive
state the switch contacts are closed to the switch ground circuit. When a switch
is pressed to an active state the switch contact is closed to the battery voltage
supply circuit. Each motor is controlled by the power seat switch through 2 motor
control circuits. The motors are bidirectional and the direction of motor rotation
is determined by which of the motor control circuits is switched to battery voltage
while the other remains grounded.