The lumbar support system incorporates an inflatable bladder, lumbar support switch and a lumbar support motor and solenoid assembly. For vehicles equipped with a bench, split bench or bucket seats without heated seats, power is supplied from the CIG LTR fuse through CKT 640 (ORN) to the lumbar support switch. On vehicles equipped with heated seats, power is supplied from the PWR ACCY circuit breaker through CKT 540 (ORN) to the lumbar support switch. Ground, with either system , is supplied from G202 through CKT 150 (BLK) to the lumbar support motor and solenoid assembly.

By placing the lumbar support switch in the inflate position, voltage is applied through CKT 767 (PPL) to the motor and CKT 768 (TAN) to the solenoid. This causes the motor to run and the solenoid to energize. Ambient air is drawn through the motor and past the solenoid to fill the bladder. When the switch is released, the motor stops and the solenoid de-energizes. The solenoid acts as a check valve and captures the air in the bladder.

By placing the lumbar support switch in the deflate position, voltage is applied through CKT 768 (TAN) to the solenoid only. When the solenoid is energized, air from the bladder is allowed to pass through the solenoid and motor to the atmosphere, thus deflating the bladder.