Hi all!
I have a well-cared-for all black 2013 CTT
Occasionally, I have an intermittent PCM communication error which sends my coolant tachometer to jump up to the redline. I have checked for leaks, repaired the dreaded T issues, fixed a small leak in my radiator, and confirmed that there isn't a leak in the coolant cross-over tube, literally no leaks (anymore). the digital display of my coolant stays pretty standard, (cool then warms up to 197-203 F) when driving, and fans kick on when needed

When the display (attached) (PCM experiences a comm error) had my friend, a mechanic with an overpriced scan tool but not a Porsche mechanic, confirm PCM comm issues then all heck breaks loose, analog coolant display shoots up to the redline, parking assist failure issue is displayed, and fans kick on full throttle. my digital display of coolant displays normal readings for the type of driving that is occurring at the time of the comm issue.

I stop the car - open the door plug in my cheap scan tool - clear codes shut the car off completely - (the key is always in the car - my model I have a fob) open/close the door to ensure everything is shut off
restart the car everything is back to normal and the car runs like the beast she is.

Any thoughts?
Lastly, I appreciate all comments, recommendations