GMC 2002 Sonoma Owner's Manual page 11

Horizontal Control: Raise or lower the front of the seat
by raising or lowering the forward edge of the control.
Raise or lower the rear of the seat by raising or lowering
the rear edge of the control. Move the seat forward or
rearward by moving the whole control toward the front
or the rear of the vehicle.
Moving the whole control up or down raises or lowers
the whole seat.
Vertical Control: Move the reclining front seatback
forward or rearward by moving the control toward the
front or rear of the vehicle.
1-4
Power Lumbar Control (If Equipped)
Press and hold the front of the control until you have the
desired lumbar support. To decrease lumbar support,
press and hold the rear of the control.
If your vehicle has this
feature, there will be a
control located on the
outboard side of the
front seat(s).