I have an 04 Silverado, digital odometer w/ settings for "personal" and "business" trips, as well as some other features. Noticed today that my Business mileage is at 77,000 miles, and the actual odometer mileage reads 39,000 some odd miles. I recently bought the truck from a dealer, mileage at the time of purchase was 37,000 some odd miles, and also have the little piece of paper signed from the dealer stating the actual mileage at the time of sale was 37,000 miles. Any ideas on why the business trip meter says 77000 miles, annual mileage avg. meter says 20,000 miles, and odometer only reads 39,000 miles? Surely the odometer doesnt start back over at 0 once it reaches 99000 miles, or did I have the wool pulled over my eyes? Any help is greatly appreciated.