This sunday my van stalled and about 8 miles up the road going down the interstate at about 65mph i felt the van shutter and the speedometer dipped sharply and returned. I took it to a local auto shop and they charged me $80 just to tell me to take it to a tranni shop!...i am pretty mad about that! Their computer picked up the following codes and this what THEY say they mean.

42 - 2-4 silenoid circuit error
21- overdrive pressure switch circuit
02- Serial buss comm test failed

I have tried to look up these codes online but all the codes i see are p### codes not double digit codes. I am irritaed that I have now take it to a tranni shop and pay to have another dianostics on it. Does anyone have an idea what's going on and what those codes really are?

THANKS!!