The last time that this thread was posted in was over 4 years ago and it has been of huge help to me.
I recently purchased a 2000 Oldsmobile Bravada with 109550 miles on it. It was working fine for a bit before I noticed that the gauges started to flash and the shifting was very temperamental... maybe not even getting out of... THIRD.
So, after I became greatly concerned with the possibility of needing to have the automatic transmission. I went nuts, being a college student - money is not really a luxury that I have. I bought the truck for $3,000 and I figured that I would probably have to invest close to $500 for various things that it needs.
A set of ball joints and tie rod ends got me an inspection sticker, but set me back around $400. In the mean time, the gauges went out randomly. Sometimes they would work; generally by wiggling the key and hitting the steering column, I could get them to work. Always, after I would get them working, the truck would really just stay in third gear. I had almost no power taking off from anywhere, but that didn't limit me from getting up to a pretty decent speed.
It was very difficult for me to gauge my speed, because my... gauges weren't working.
Like I said, I thought I was faced with replacing an automatic transmission - which would easily run me $1500. So, I started looking around and I came across this jewel. This thread saved me so much money, it's not even funny.
Guess what the problem was? Yup, the ignition switch. It cost almost nothing to do, and the results are fantastic. The car shifts fantastically, I have a ton of power in all gears and it works great.
The only guess from the guy that I had the thing repaired by was that since the ignition switch signals the transmission when to work, some of the electrical wiring doesn't signal the solenoids properly and that's where you get the codes from.
I got 3 out of the 5 codes that "oldsjoe" got, so don't be concerned if you don't have the exact codes that he does.
Just some important notes, my Bravada has a remote starter and power locks (as do all others) which are connected to the ignition switch - so be mindful if you do this yourself. Even if you're a little bit off doing anything on the switch, you could run into a problem like I had.
Of course, this is also relevant to the GMC Jimmy and Chevrolet Blazer generally from 1995, 1996, 1997, 1998, 1999, 2000, 2001. I'm trying to get some tags here, so that if anyone has the same problem - they can easily find the information.
The Service Engine Soon (SES) light went off, and I am completely satisfied!!!
Thank you guys!