Having promblems with my instrument cluster, the speedodmeter is stuck on 50 mph and the oil gauge wont go back to 0. its a 2003 chevy trailblazer with a 4.2 liter and air bag light stays on

I know that you can't trust the Trailblazer instrument cluster at all. Our 2007 was the biggest mess, but it's the gauge clusters and not the sending units that are defective. There are Good Folks making a Living doing nothing more than rebuilding Trailblazer Instrument Clusters and you can google that. The only way to know for sure is to verify with other means. For example, For MPH on the speedometer simply drive an indicated 60 mph on any Interstate Hwy that has Mile markers and time how long in seconds it takes to get from one marker to the next. 60 seconds means the speedometer is perfect. A temperature gun can tell you if the temp gauge is working right or not. Is your mileage changing or are the gauges giving you bad info? My advice is start at the gauges because they will drive you nuts. I hope that helps you!

Take the truck to a place like Autozone to have them read the code the engine light is producing. Usually done for free. At this point, we can help narrow it down with the codes. As for the gauges going haywire, TB's have a problem with te stepper motors on the back of the instrument cluster, these little inexpensive motors, may need to be replaced. OR you could have a problem with your ignition switch.

Have the various systems scanned and see if they show a fault code, I suspect they will. As far as the gauges go that sounds like the rebuilder screwed up.

Pretty common problem with these. Here's a guide to learn how to fix GM instrument clusters yourself, I used it to fix mine and it worked great.How to guide for Trailblazer instrument cluster repair

Pretty common problem with these. Here's a guide to learn how to fix GM instrument clusters yourself, I used it to fix mine and it worked great.How to guide for Trailblazer instrument cluster repair

Pretty common problem with these. Here's a guide to learn how to fix GM instrument clusters yourself, I used it to fix mine and it worked great.How to guide for Trailblazer instrument cluster repair

speed sensor in the tranny is malfuntioning is the only thing I can say. Unless its your instrument cluster itself. Good Luck.

Call your local dearship with your vin, and ask if the special policy for the IPC (cluster) appies to your truck. Some of these have a special policy which would mean that you could have it fixed at the dealer for very cheap. Otherwise you will need to have the cluster sent out and it will need to be repaired, it's not very cheap either, and it will need to be programed at the dealership also after it's replaced.

"The Fix" works...I would have not believed it untill I did it.... Start the car in reverse and about 5 times later it reset the speedometer back to zero.....wow!

Common issue on teh 03-06 Trailblazer instrument clusters, it's caused by failing stepper motors on the cluster's circuit board. It is fixable, check out this page for more on how to get it fixed - Trailblazer oil gauge broken