Engine in protection mode

[nunuk]

Hi guys, i recently had an issue with the speed sensor shaft, it got loosen and out of place far from the sensor, making the speedo going crazy, light from engine on in the dashboard, and the engine went into protection mode, cutting revs at 5k. That was fixed by welding the shaft. The car went ok for a couple of times.

This time i got no engine fault light on the dash, the speedo seems to work fine (just saw it rattling once at high revs fro a sec, but it's working fine mostly), but the engine has gone again into protection mode. I don't have a dealer at hand right now, and i'd like to hear your thoughts before i hand the car over my beloved old fart but competent Saab mechanic without a hint on where to start looking. The car is a 2019 485S. Any info would be very much appreciated.