Lumbar Adjustment; Reclining Seatbacks - GMC Chevrolet Silverado 2500HD 2021 Owner's Manual

Some vehicles are equipped with a feature
that activates a vibrating pulse alert in the
driver seat to help the driver avoid crashes.
See Driver Assistance Systems 0 247.

Lumbar Adjustment

Power Lumbar
To adjust the lumbar support, if equipped:
Press and hold the control forward to
increase or rearward to decrease upper
and lower lumbar support at the
same time.

Reclining Seatbacks

Warning
Sitting in a reclined position when the
vehicle is in motion can be dangerous.
Even when buckled up, the seat belts
cannot do their job.
The shoulder belt will not be against
your body. Instead, it will be in front of
you. In a crash, you could go into it,
receiving neck or other injuries.
The lap belt could go up over your
abdomen. The belt forces would be there,
not at your pelvic bones. This could cause
serious internal injuries.
For proper protection when the vehicle is
in motion, have the seatback upright.
Then sit well back in the seat and wear
the seat belt properly.
Seats and Restraints
Do not have a seatback reclined if the
vehicle is moving.
Manual Reclining Seatbacks
Warning
If either seatback is not locked, it could
move forward in a sudden stop or crash.
That could cause injury to the person
sitting there. Always push and pull on
the seatbacks to be sure they are locked.
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