SeatsLumbar Support Description and Operation
Lumbar Support Description and Operation
Lumbar Support Components
The driver and front passenger pneumatic lumbar support system
consists of the following components:
| • |
Seat lumbar support
switch |
| • |
Seat lumbar adjuster valve
assembly |
| • |
Seat lumbar support
pump |
Circuit Description
Battery voltage is supplied at all times to the driver and
passenger seat lumbar support switches through 15 A fuses located
in the underhood fuse block. When a lumbar switch is pressed to
inflate the lumbar support, battery voltage is applied through the
switch contacts and the inflate control circuit to the seat lumbar
adjuster valve assembly. In response to this signal, the lumbar
adjuster valve assembly energizes its internal inflate solenoid and
applies battery voltage through the seat lumbar support pump
control circuit to the pump. The pump runs to inflate the
appropriate lumbar bladder until the switch is released. When the
switch is pressed to deflate the lumbar support, battery voltage is
applied through the switch contacts and the deflate signal circuit
to the lumbar adjuster valve assembly. The lumbar adjuster valve
assembly energizes its internal deflate solenoid and air is
released from the bladder until the switch is released.
Description of Operation
The following describes the lumbar support operation and how the
lumbar adjuster valve assembly responds to each of the lumbar
switch inputs:
| • |
When the lumbar support switch
pressed in the FORWARD direction, the lumbar adjuster valve
assembly will command the lumbar support pump ON and start to
inflate the lower lumbar support bladder. After the lower lumbar
inflates to approximately 50%, the lumbar adjuster valve assembly
will slowly inflate the upper lumbar bladder until both bladders
are 100% inflated. The lower lumbar bladder will inflate to 100%
first. |
| • |
When pressing the lumbar
support switch in the REARWARD direction, the lumbar adjuster valve
assembly will slowly deflate the upper and lower lumbar support
bladders until the switch is released or they are both 100%
deflated. |
| • |
When the lumbar support switch
is pressed in the UP direction, the lumbar adjuster valve assembly
will slowly inflate the upper lumbar support bladder until the
switch is released or the bladder is 100% inflated. |
| • |
When the lumbar support switch
is pressed in the DOWN direction, the lumbar adjuster valve
assembly will slowly deflate the upper lumbar bladder while it
inflates the lower lumbar bladder. The lumbar adjuster valve
assembly will continue this operation until the switch is released
or the upper lumbar bladder is 100% deflated and the lower lumbar
bladder is 100% inflated. |
|
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16 Body & interior
