thanks guys, i went and checked it out today, the manual says that a door lock that bobbles as car leaves floor could cause the problem, i checked all the items in the troubleshooting help section of this fault. cleaned all locks and gate switch rechecked switch, L3S, made sure it does not open until car is below bottom floor by a few inches. if it comes in again, i have instructed mechanic to swap the board with another car, will see what happens. thanks again for the input