hi everyone

we have been tuning 383 and 406 ls engines with 4l80 swaps... some time ago we did 2 lsx engines dor 2008 trucks, theyre dirven like 2000 miles a year and suddenlu they both got 0606 code. I tried a new VCM on one... the same after 20 hours of driving. The trucks only throw this codes when drag racing on the starting line ( brake satalling to get on the converter or when you relase the brakes). DO you have eny idea where to look at?

I have some suspicius components like:

1.we used a corvette 90mm TB intead of the 90mm one form hte TBSS
2.Could the trans max torque input be maxed
3. are ABS doing dsomething strange ( one owner told me it doesnt flash the light whit the ABS fuse pulled)
4. Something with 4x4, they only throw the code when using 4x4 to drag race


I have read that this code can be triggered by some other conditions and it will be on until I fix that condition.

any comment or pointer will be really apreciated