Gmc envory gauges goes off while driving and cuts

If you are under warranty, these will be covered for repair. Otherwise:

The mechanical gauges for the tach, speedo, fuel, etc. are all controlled by small stepper motors soldered in place on the circuit board of the dashboard cluster. They can become stuck in an arbitrary position, or indicate values significantly above or below actual levels when driving, parked and with the key on or off. If these sound like your symptoms, read on. Otherwise, you may have a different problem.

Your dealer will tell you it's $300+ to replace the cluster, plus labor to install and program it. If you can use a socket wrench (or simple nut driver) and a low wattage (20 to 30 watt) soldering iron, you can save yourself literally hundreds of dollars.

The parts you need are available on eBay. Search "X25168" (the part number of the stepper motor). They're under $3 each. I replaced a single motor in a little over an hour - from dash removal and repair to re-installation. You might want to replace the dashboard cluster lamps, while you're at it. When I completed this job, I found that 3 lamps no longer lit up. They're on all the time and as a result, the filament is pretty brittle. Try as you might, you'll probably not be able to prevent one or two from failing. The people that offer the stepper motors on eBay also sell the lamps - check their "store". You can combine them with the motors in the order to save a few bucks on the shipping. I'm waiting for my lamps to arrive.

You can learn how to make the repairs (complete with photos) on this page (visible after free registration):

http://forums.trailvoy.com/showthread.php?t=48886

This site has tons of information that is very helpful to owners of the GMC Envoy and Chevy Trailblazer and I highly recommend it.

I hope this was helpful!