1994 GMC Suburban Owner's Manual - Page 134

You can only drive fora short time with the reading in either warning zone. If you must drive, turn off all unnecessary accessories, and have the vehicle serviced as soon as possible. Center High Mount Stop Lamp (CHMSL) Your vehicle has a Center High Mount Stoplamp (CHMSL) located above the tailgate glass orabove the rear load doors. If items areloaded on the roof of the vehicle, as in a luggage carrier, care should be taken not to block or damage the CHMSL unit. Convenience Net If you have a convenience net, it is stored i n a pouch attached to the spare tire. 2-78