Speedometer

Mine did the same but not in the cold. GM extended the warranty on this gauge cluster problem. Call dealer to see if it is still covered. Mine was fixed for free Dec. 2009 on my 2004 Tahoe. Good luck!

It sounds like and internal fault with the guages cluster. The only way to tell for sure is to check for the proper speed input to the speedometer when the fault is current. You will need a scan tool for this kind of test.