viper alarm system

I hope ypu guys can help. I have an early '99 Tahoe and the remote start is failing as well as the rear hatch opener. the locks work but thats it
Thanks

As far as failing...do they work at all? Or sometimes...? Does the hatch release button work in the truck still, and does it work on the factory keyless button if it had that option? When you try to remote start it what happens? -Nothing or lights flash or ????
It could be the brain-box going bad, if you had it installed professionally there should be a life-time warranty on it through DEI (makers of Viper). And usually if you had someone install it they should be able to trouble-shoot it also.

I wanted to add that the factory immobilizer could be going bad, the dealership should be able to check that out easily and check for recalls on it. Good luck!