How does changing the programming affect claims for factory warranty work?

 

It is STRONGLY recommended by some chip manufacturers to return the vehicle to stock and have a few drive cycles before taking the vehicle in for service along with disconnecting the battery to reset the PCM(computer). A drive cycle is when you operate your vehicle a few times to help clear or reset any information that may be left in the vehicles PCM. Of course dealers vary and none that I know will tell you it is o.k. and can easily say that your warranty is void. Unless they can prove that the modifications you made are the sole cause of your problems they cannot refuse warranty.(but they do). So it is an item that you need to use with caution. The tuner itself can help calibrate for tires, adjust gear changes as well as check, diagnose and clear trouble codes. So, in itself it is a very handy device. Also, many dealers do not want to address the delay throttle issues that are apparent in some of the newer vehicles so you have to do it yourself if you want to see any improvement. Heck, the dealer I went to could not recalibrate for my larger tires. So I bought a tuner and when I need service for any reason. I will reload the stock tuning; Drive the truck a few times before I drop it off for service.

 

You cannot void a warranty without the problem present. And they can either ford all your warranty or just the powertrain for instance.

The dealer can only change tire sizes that were offered on that vehicle. It will come up with an error stating the tire size is not in recomended operating range and not let you change it. BUT you can set up the PCM figuring out different rear gear ratios to make it work right.