lumbar support GMC SONOMA 1999 Owner's Manual

1-3 Manual Lumbar Support (If Equipped)
If you have this feature,
there will be a knob on the
outside of the driver and
passenger bucket seats.
Turn the knob toward the front of the vehicle to increase
lumbar support and toward the rear of the vehicle to
decrease lumbar support.
Reclining Seatbacks
(Bucket Seats or 60/40 Bench)
To adjust the front seatback,
lift the lever on the outer
side of the seat.
Release the lever to lock the seatback where you
want it. Pull up on the lever and the seat will go to an
upright position.