GMC 2001 Sonoma Owner's Manual page 16

Manual Lumbar Support (If Equipped)
Turn the knob toward the front of the vehicle to increase
lumbar support and toward the rear of the vehicle to
decrease lumbar support.
If you have this feature,
there will be a knob on the
outside of the driver's
bucket seat.
Reclining Seatbacks (Bucket Seats or
60/40 Bench)
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.
To adjust the front seatback,
lift the lever on the outside
of the seat.
1-3