I would check the power supply for the group boards, make sure 35 and 5 volt supplies are at appropriate levels with minimal ac ripple. I have seen group problems with power supplies in the 30 volt level for 35 and 4.5 for the 5 volt supply. Low voltage and high ac ripple on goolean logic power supplies cause many intermittent unexplained and unanswered problems. ps also check individual car power supplies as well, If I were rich i would bet you a 100 dollars this is a power supply problem. If your not sure of the ac ripple factor compare values between power supplies of other cars. I would like to believe it would be below 100 mv ac.
