Air Conditioner problems of the 2009 Smart Fortwo

Within the space of three months, in the middle of driving my Smartcar, my dash display has gone from showing d (for drive) to n and then flashing three vertical bars. I have lost all control of driving the car and luckily there was space on the side of the road to coast to a stop. When trying to turn the car back on, the three bars remain. There is a way through the shifter to restart the car or at least getting it into neutral. A series of pumping the brake, turning the start key and trying to move the shifter back and forth through gears. Eventually, the car will start. Unfortunately, the three bars of death (as nicknamed on the Smart car forums) can happen for any numerous types of faults such as weak battery to faulty communication with the transmission, to heater/air conditioning operating unit is defective. The list is long. The problem is my car has completely stopped working in the middle of the road without warning and this could be very dangerous.