My wife has an 02 cavalier that has had few problems until recently when the daytime running lights and high beams stopped working. I have replaced the headlights and the relay and checked all the fuses associated with the headlamps. She recently took it to the shop where they spent 3 days trying to figure out what was wrong. When it is shifted in to gear it makes a clicking noise and the service engine light comes on if the headlamps are not turned on when it is shifted in to gear. The mechanic we took it to found a couple of broken wires and replaced everything between the battery and the headlamps. It still does the exact same thing. He recommended taking it to the dealer to have them use some more specialized diagnostic equipment on it.
Has anyone else encountered this? If so, what was the diagnosis and how pricey of a fix was it?