When I turn on my bike, the speedometer goes up to 120, back to 0, and displays "DIAG," which I presume stands for "diagnostic" in the window.

The bike was serviced about 1500 miles ago, and no warning lights are on. It seems to be running fine.

I called the local dealership, and the guy I talked to on the phone didn't have a clue, but told me to bring it in so they could hook it up to the computer.

Any ideas what's going on before I hand them a fistful of dollars?

 

What you are describing is a typical result of the odometer reset/selector button being held in when the key is turned to the ON position. This is how you normally enter the diagnostic mode.

Does the odometer button work properly? It sounds like it's stuck in the depressed position.

 

Thanks a million. You clearly know a lot more about the bike than our local service department. I have never touched that button, but I'm headed out to the garage now to play with it.