I have a P120SE that has been working flawless for about 30 flights. Today it suddenly died on the startup of my intended second flight. First the glow plug went. I replaced the glow plug but then it started to behave very strange. Once RX is turned on the fuel pump starts spinning directly. Luckily the fuel valve stays closed. The GSU reports pump voltage to be 0. It reports temperature approx -30 deg (unstable) and it claims the ECU battery to be over 9V even though it’s a 7.4V lipo. Any ideas what could cause this behavior?

I hope it is something I can reset so that I don’t have to send the motor in. I tried resetting the ECU to factory defaults, but that did nothing. What is really odd (and dangerous) is that the ECU does not realize anything is wrong and I could in theory attempt to start the engine. I believe that would result in a spectacular fireball once the fuel valve opens and with the pump already spinning at half speed