I have a 1999 Grand Prix with a V6 and automatic. It runs good but it won't shift out of first. any help would be appreciated.

Im not very experienced in these kinds of probelms, but it must be your transmission thats acitng up. Have you tryed manually shifting up in gear?

Is your SES light on? Either way you need to get it scanned.

There is no lights on and nothing to indicate there is a problem with the exception of the fact it won't shift out of first gear. I've tried to manually change gears but still nothing.

Did you pop the cable shift adjust clip out of its lock position before trying to manually shifting the gears?