Reprogram Tire Size With Tech Ii

[mxz905]

Installed slightly larger tires on my 05 Seirra a couple months back went up to a 285/70R17 from the stock 265. I have access to a Tech II this weekend and was hoping someone out there could clarify if the Tech II can reprogram the tire size.

 

I've been given conflicting stories the first being yes it will the second being it will only reprogram to sizes available on that truck from the factory so if you had a 245/70R17 but as an option a 265/70R17 was available I could reprogram to that but if I put a larger tire such as the 285 it wouldn't know how to do that.

 

Can anyone confirm what the Tech II can do the 285/70R17 I have on it where no a factory option. I basically need to drive a little out ofthe way to get the Tech II so if it can't do it I won't wast my time.

 

While I'm at it is there anything else I can/should adjust with the Tech II while I have access. Thanks

[Spurshot]

I installed the same oversize tire recently. Justin apparently adjusted within limits of the gear ratio, but could only get about 1/2 mph closer on my 2 mph (@ 70 mph) error. He was worried about a ABS fault message if he changed the gear ratio in the ECM or TCM. Possibly, a Tech II is needed to change the BCM ABS settings? He didn't elaborate on the cause of the possibly ABS fault.