Pneumatic Seat

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, pneumatic seat module, and the solenoid valve assemblies.

Battery positive voltage (B+) is supplied at all times to console seat switch via CKT 640 (ORN). Whenever an adjustment is to be made, the seat select switch must be set to the LEFT or RIGHT position. This action supplies battery positive voltage (B+) to each of the four comfort switches and prepares a ground path for either the LH or RH seat solenoid valve assembly.

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 positive voltage (B+) is supplied via CKT 766 (WHT) to the inflate relay, which is energized. When any one of the switches is moved to the DEFLATE position, battery positive voltage (B+) is supplied via CKT 764 (GRY) to energize the deflate relay. The inflate and deflate relays are grounded via CKT 1250 (BLK) to ground G202.

At the same time, battery positive voltage (B+) is also supplied to the associated solenoid coil in the seat solenoid valve assembly from the other half of the feature switch. If, for example, the seat select switch is moved to the LEFT position and middle lumbar switch is held in the INFLATE position, the inflate relay is energized via CKT 766 (WHT) and the middle lumbar solenoid in the LH seat solenoid valve assembly is energized via CKT 763 (BRN). Battery positive voltage (B+) 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 valve assembly is via CKT 797 (TAN) from the console seat switch, through the seat select switch, via CKT 769 (BLK/WHT) from lumbar control module, through the normally closed contacts of the pressure cut-out relay, and to ground G202 via CKT 1 250 (BLK) through the pneumatic seat module.

The purpose of the deflate and inflate relays is to supply battery positive voltage (B+) of the proper polarity to the seat air pump. When the inflate relay is energized, battery positive voltage (B+) is supplied through the closed contacts of the inflate relay to seat air pump via CKT 768 (PNK). The seat air pump is grounded through the normally closed contacts of the deflate relay via CKT 767 (ORN) through the pneumatic seat module.

When the deflate relay is energized, battery positive voltage (B+) is supplied to the seat air pump through the closed contacts of the deflate relay via CKT 768 (ORN). The seat air pump assembly is grounded through the normally closed contacts of the inflate relay via CKT 768 (PNK) through the pneumatic seat module.

In this way, the seat 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.