A guy I know has an 07 Silverado with an E38 ECM. He did some work to it (supercharger, swapped rear axles). He bought a tune for it for the supercharger, and now it is throwing an ABS light. He called me to see if I could recalibrate it for the new gears it had. I changed the gear ratio, but it was still throwing the code. I went back by this morning and drove the truck. After going approximately 1.5 miles, the light would come on. I tinkered with it and finally got the speedo reading correctly with a GPS. I drove the truck about 5 miles and got no lights. I assumed it was fixed, but I just found out he drove it about 20 miles to the next town, and the lights came on just as he was getting into the next town. What can I do to get this thing fixed? I am an idiot when it comes to the gasser ECMs. Anyone have any advice? I see there is a cell for driven wheel circumference and one for non-driven wheel circumference. I'm guessing these are what I need to change, but is there a PID I can log to see what the front wheel sensors are seeing? And how do I adjust them? Any help or advice would be greatly appreciated. Thanks.