2009 Buick Lucerne Owner's Manual - Page 10

Power Lumbar For vehicles with a two-way lumbar control, press the control top or bottom to increase or decrease support in the lower seatback. On vehicles with a four-way lumbar control, press the control forward or rearward to increase or decrease support in the lower seatback. Press the top or bottom of the control to raise or lower the support in the seatback. The lumbar support may need to be re-adjusted when changing the seating position. On vehicles with power lumbar, the control is located on the outboard side of the front seats. 1-6