I can't start the engine.

When I turn the ignition to on, transmission lettres don't appear on th instrument cluster. I move the shifter back and forth then try again, and still no start.

I also tried in neutral, same result.

My mechanic tell's me it's maybe a major tranny problem.

I got 179000 Km

Thats a bad sign.

If you aren't getting the "AT Check" at startup I would be worried.

Yes I am getting the

AT Check light

does it go off?

I guess what you're trying to say is that the "gear indicator" light on the dash is not displaying your gear, is that correct? And your car isn't starting because of this?

So you are stuck in a "no gear" right now. Does this ONLY happen for (P)Park or does it happen for your other gears as well?

My mechanic found the probleme by pur luck.

Blown fuse.

And yes the gear indicator didn't display any of the gears.

Now the probleme is, why did the fuse blow?

did you spill a drink into your center console? water get into the car somehow? Who knows. If it keeps popping the fuse then you need to look for a serious issue. If not, carry on driving as normal.