Pneumatic Seats

The sport seats incorporate a power inflate/power deflate pneumatic system used for controlling comfort features of the seats by inflating or deflating air cells within the seats. The pneumatic system consists of the console seat switch, seat air pump assembly, lumbar control module and the seat solenoid valve assemblies.

Power is supplied at all times to terminal C of Connector C1 on the console seat switch. Whenever an adjustment is to be made, the seat select switch must be set to the L or R position. This action supplies battery voltage to each of the four comfort switches and prepares a ground path (from terminal D, connector C1, on the console seat switch) for either the LH or RH seat solenoid/valve assemblies.

All four of the comfort feature switches operate in a similar manner. If any one of them is moved to the INFLATE position, for example, battery voltage is supplied through the WHT(766) wire to the inflate relay, which is energized. When any one of the switches is moved to the DEFLATE position, battery voltage is supplied through the GRY (764) wire to energize the deflate relay. The inflate and deflate relays are grounded through the BLK (1250) wire at ground G202.

At the same time, battery voltage is also supplied to the associated solenoid coil in the seat solenoid/valve assemblies from the other half of the feature switch. If, for example, the seat select switch is moved to the L position and middle lumbar switch is held in the INFLATE position, the inflate relay is energized through the WHT (766) wire and the middle solenoids in the LH seat solenoid/valve assembly are energized through the BRN (763) wire. Battery voltage is also applied to the middle lumbar solenoid in the RH seat solenoid/ valve assembly, but the solenoid is not energized because there is not a path to ground. The ground path for the LH seat solenoid is through the TAN/BLK (797) wire to terminal F on Connector C2 of the console seat switch, through the seat select switch, through the BLK/WHT (769) wire to terminal A of the lumbar control module, through the normally closed contacts of the pressure cut-out relay, and to ground G202 through the BLK (1250) wire at terminal B of the lumbar control module.

The purpose of the deflate and inflate relays is to supply voltage of the proper polarity to the seat air pump assembly. When the inflate relay is energized, battery voltage at terminal F of the lumbar control module is supplied through the closed contacts of the inflater relay to terminal A of the seat air pump assembly through the PNK (768) wire. Terminal B of the seat air pump assembly is grounded through the normally closed contacts of the deflate relay and the BLK (1250) wire at terminal E of the lumbar control module.

When the deflate relay is energized, battery voltage is supplied to terminal B of the seat air pump assembly through the closed contacts of the deflate relay. Terminal A of the seat air pump assembly is grounded through the normally closed contacts of the inflate relay and the BLK (1250) wire and terminal E of the Lumbar Control Module.

In this way, the air pump runs in either direction to inflate or deflate the bladders in the seat as required.

Should any of the bladders become fully inflated or deflated, the increased pressure or vacuum operates the pressure cut-out switch, which allows the pressure cut-out relay to be energized whenever the air pump is operated. When the pressure cut-out relay is energized, the air pump motor circuit and solenoid valve circuit are interrupted.