While driving the brake and ABS lights on the instrument panel light up. This has occurred while driving of the freeway and on city streets. Sometimes these lights go off and sometimes they remain lighted. When this happens I fear that there is a problem with the brakes and have taken this matter to a mechanic. The brakes were examined and he found nothing wrong. This is very startling to the driver and of great concern. This appears on internet searches and it appears that 100,000 plus individuals have this problem. I have contacted the dealer and obviously this matter has been brought to there attention. Yet they claim they are unfamiliar and want to charge $600 to diagnose and then likely more to fix. This is obviously a lie as there is no way that one could be reading so much about this on the internet if it was not a problem in the GMC Sierra trucks. Some claim it is a faulty circuit board while others have lost the use of their brakes. This is of great concern. This occurs while driving and the vehicle is in motion and sometimes at high speeds on a freeway.

- North Hollywood, CA, USA

Instrument panel works very rarely, can't tell how fast you are going or what gear you are in and the antilock brakes make it so the vehicle won't stop when you are moving at low speeds.

- Norfolk, NE, USA

While driving 60 mph vehicle stalled. The consumer tried to restart it, but was unable to do so. The consumer had the vehicle towed to the dealer for inspection. The mechanic replaced the electric ejection pump, however the problem recurred. No matter what speed the vehicle was going, the engine would die as the key was turned off. Sometimes the vehicle restarted immediately, but sometimes it wouldn't restart until it was "worked with." The electric injection pump was replaced for a third time. Two new alternators had been placed in the vehicle but at times, frequently killed the pump which drained the battery. The vehicle had stopped in fast moving traffic. The emergency flashers were inoperative, sometimes there would be a hard start then the service engine soon light would come on, the vehicle would die when the headlights were turned on, the A/C switch had broken, and there were leaking lines.

- Princeton, WV, USA