Make sure your 24v power supply is not low, I had a dmc that would not run, I would plug in my laptop, using world freedom software, and i was able to communicate and adjust anything on the unit. As soon as I unplugged the laptop, the car would not run. If i plugged it back in, it would run again. It turns out the 24 volt supply was around 19 v, for some reason when i plugged in the laptop to the unit, it raised the voltage to around 22 volts which would let it communicate to the system.