Engine/Transmission (1998.5 - 2002) Banks brake / Smart lock problem

[silverram03]

I have a question for anybody familiar with the banks brake and smart lock set up. While my Dad was on his way up to the mountains today, in his 1999 4x4 2500 auto 47,000 miles and transmission just serviced about 500 miles ago along with new mag-hytec deep pan 4+ quart as well as governor solenoid and transducer (if thats what its called) the truck started to shake so bad that the cup holder jumped up and down like crazy. So I disconnected the banks brake and smart lock controllers with the supplied pig- tail jumpers and the problem has gone away, so what could be causing this? (fluctuating line pressure/bad electronics) The truck has only had 11,000 miles put on it since the banks brake and smart lock were installed and just passed its 2-year warranty. Any help you guys can give me is greatly appreciated.