How do you reset the check engine light on a 2004 Neon?

Pull the codes from the computer, match the code to the troubleshooting procedure, follow the procedure to find the source. Repair the source, light will go out if that was the only problem. There are "monitors" or self test the computer runs the car through, if a problem occurs, it may not run all of the self tests until that problem is taken care. Therefore, another problem may exist.

The following worked on my 2000 Neon: After replacing what the diagnostic test said was bad, I disconnected one of the battery cables for approximately 30 minutes. I then made contact or touched the battery terminal with the cable battery clamp three (3) times and then connected the cable to the battery. It reset the computer.