2003 Chevrolet Tahoe Owner's Manual - Page 13

If your vehicle has power seats with a power recliner, see Power Seats on page 1-4 for further information on how to operate the reclining seatback feature, Sitting in a reclined position when your vehicle is in motion can be dangerous. Even if you buckle up, your safety belts can't do their job when you're reclined like this. The shoulder belt can't do its job. In a crash, you could go into it, receiving neck or other injuries. The lap belt can't doits job either. In a crash the belt could go up over your abdomen. The belt forces would bethere, 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 your safety belt properly. But don't have a seatback reclined if your vehicle is moving. 1 -6