Also... if you are using either a "GYMKO" Tech 2 or some other Pass-Thru Device
(J-2534) using a laptop with the proper software to access your PCM and perform an update to the PCM via a Subscription with
ACDelco TIS2WEB Services... Consider this:
After you complete your initial Hardware and Vehicle Recognition Set Up Page, there MAY be an opportunity to CHOOSE from the Different Sub-Options for your Power Train Control Module and Transmission Types,
and hopefully include a selection of
OPTIONAL TIRE SIZES.
If this is going to work, You MUST confirm what your particular RPO Codes are available on that list and then look for any additional choices on that menu that will accept any alternative Tire Sizes that match your new configuration.
Please bear this in mind:
THIS is NOT a Casual Choice just for the Tires. EVERYTHING else listed there must match the alterations you have made on your particular vehicle.
DO NOT USE METHOD UNLESS YOU CAN CONFIRM THAT WHAT YOU HAVE DONE TO YOUR VEHICLE IS ON THAT MENU prior to accepting these Parameters and continuing on to Update your PCM Calibration and fix any other outstanding issues.
Here is a Video demonstrating what these procedures look like on a Non-GMT-360
so you can see first hand how this works: