2004 Buick Regal Owner's Manual - Page 127

Tachometer If the vehicle has a tachometer, it displays the engine speed in thousands of revolutions per minute (rpm). Safety Belt Reminder Light When the ignition key is turned to RUN or START, a chime will come on for several seconds to remind occupants to fasten their safety belts. The safety belt light will also come on and stay on for several seconds, then it will flash for several more. Notice: If you operate the engine with the tachometer in the shaded warning area, your vehicle could be damaged, and the damages would not be covered by your warranty. Do not operate the engine with the tachometer in the shaded warning area. If the driver's belt is already buckled, neither the chime nor the light will come on. 3-29