quick question - ABS / BRAKE light after Reflash

[Boost]

On an '05 1500 4wd truck with a 5.3, I used the Speedo Calculator to dial in the HUGE tires (35"). It drove fine up and down the street and the cell phone GPS is reporting that it is within 1-2 miles per hour of accurate (must have been way off). However, after about 10 minutes on the highway, the ABS and BRAKE lights came on the dash. I have not had a chance to scan it for "C" codes, but basically I am thinking that unless one of the modules freaked out from the reflash (very rare, I am not thinking this), it has to be something with the speedo calculation, right?? In the past, there have been glitches in the S.C. and also sometimes you have to paste in values manually (before). I guess one thing I can try is put back the stock values for tire size to see if it resolves the warning light, even if the speedo is back way off, and look for a fix. Thanks!

[Boost]

With a different program, still sets C0245 on the highway, "wheel speed sensor frequency". HELP

[Boost]

(only when putting in the correct tire size to speedo calc.)

[joecar]

The ABS controller performs sanity checks and probably needs to be reprogrammed (I don't know how).

[Boost]

I guess you mean reflash with a Tech2 at my job to the highest possible wheel size allowed (way less that 325/60/20), would that bring it within sanity range? But I still don't understand why it freaks out after I do the speedo calc, how would the EBCM know anything?

[joecar]

I think the ECM may send VSS (via a message on the can bus) to the EBCM, and the EBCM performs calculations and sanity checks... the service manual doesn't provide enough detail.