Operation CHARM: Car repair manuals for everyone.

Lumbar Supports

PNEUMATIC CONTROLS

Each seat incorporates a power inflate/power deflate pneumatic system used for altering the contour of the seat. This is accomplished by inflating and deflating a set of individual air bladders within each seat. Each pneumatic seat system employs the following electrical components:
^ Lumbar Support Switches
^ Lumbar Manifold
^ Lumbar Relay Module
Power is supplied to the Lumbar Support Switches at all times through Circuit Breaker A. Each of the individual pneumatic adjustment switches within the seat control has battery voltage applied to it. When lumbar support is requested, the Lumbar Support Switch applies voltage to the selected solenoid at the Lumbar Manifold.
The Lumbar Manifold is grounded through the Lumbar Relay Module. At the same time, the Lumbar Support Switch applies battery voltage to the selected inflate or deflate relay within the Lumbar Relay Module. The Lumbar Relay Module applies power to the Seat Air Pump Assembly in either the forward direction (inflate) or the reverse direction (deflate).
The ground to the Lumbar Manifold is lifted when a pressure/vacuum sensor inside the Lumbar Relay Module senses a bladder full/empty condition. In response to these conditions the Lumbar Relay Module shuts off the pump and lifts the ground to the air management manifold until the switch paddle is released.