For 1990-2009 cars

### Power Lumbar System Operation

The power lumbar system is controlled through the power lumbar switch. Battery voltage is supplied to the power lumbar switch through the SEATSW 40A fuse in the underhood BEC and the Power Seats 20A circuit breaker in the driver seat wiring harness. While the lumbar switch is in an inactive state the switch contacts are closed to the lumbar switch ground circuit. When a lumbar switch is pressed to an active state the switch contact is closed to the battery voltage supply circuit. The lumbar adjuster motor is controlled by the lumbar switch through 2 motor control circuits. The lumbar adjuster motor is bidirectional and the direction of adjuster motor rotation is determined by which of the motor control circuits is switched to battery voltage while the other remains grounded.