This is not an unheard of problem in the full size trucks. Normally the failure is the instrument panel itself. These have been found to be such a common failure that gm has actually extended the warranty for this problem. Proper testing would require the access to a class 2 scan tool. Here is some info on the extended warranty. The mileage you have listed actually makes you over the allowed mileage though. The gm bulletin #07187A is where gm actually has extended this warranty.
Some customers of 2003-2004 model year Cadillac Escalade, Escalade ESV, and Escalade EXT; Chevrolet Avalanche, Silverado, Suburban, and Tahoe; and GMC Sierra, Yukon, and Yukon XL vehicles have reported that one or more of the instrument panel (IP) cluster gauges stick, flutter, or become inoperative. This may cause inaccurate readings.
This special coverage covers the condition described above for a period of 7 years or 70,000 miles (110,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.
Dealers are to replace the instrument panel cluster after the condition has been verified. The repairs will be made at no charge to the customer.