Lumbar Support Description and Operation (W/O A45)

The driver and passenger seat lumbar support systems each consist of the following components:
^ Lumbar Switch
^ Lumbar Horizontal Motor
^ Lumbar Vertical Motor
^ PWR SEAT Circuit Breaker 30 A

Power Lumbar Switch
Battery positive voltage (B+) is supplied at all times to the driver and passenger seat lumbar switches from the PWR SEAT Circuit Breaker located in the rear fuse block. Both lumbar switches are grounded through the switch ground circuit and C 301. The lumbar switches provide both power and ground to the selected lumbar motors.

Motors
The lumbar system consists of two lumbar motors (horizontal and vertical) that operate independently of each other. Each motor contains an electronic circuit breaker (PTC) that will reset only after voltage has been removed from the motor The lumbar horizontal motor moves the lumbar forward and rearward and the lumbar vertical motor moves the lumbar up and down.

Horizontal
When the lumbar switch is operated to move the lumbar rearward, battery positive voltage (B+) is applied through the lumbar rearward switch contacts and the lumbar motor rearward control circuit to the lumbar horizontal motor. The motor is grounded through the lumbar forward switch contacts and the lumbar motor forward control circuit to the horizontal motor. The motor runs to drive the lumbar rearward away from the occupant's back until the switch is released. Moving the lumbar forward works similarly to moving the lumbar rearward, except that battery positive voltage (B+) and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Vertical
When the lumbar switch is operated to move the lumbar up, battery positive voltage (B+) is applied through the lumbar up switch contacts and the lumbar motor up control circuit to the lumbar vertical motor. The motor is grounded through the lumbar down switch contacts and the lumbar motor down control circuit to the vertical motor. The motor runs to drive the lumbar up until the switch is released. Moving the lumbar down works similarly to moving the lumbar up except that battery positive voltage (B+) and ground are applied on opposite circuits causing the motor to run in the opposite direction.

"For a description of the RPO Code(s) shown in this article or any of the images therein, refer to the RPO Code List found at Vehicle/Application". RPO Codes