Problem The 1.6 petrol doesn't start anymore


The problem with an A3 1.6 petrol from 98.

When crossing an embankment near the pedestrian crossings, the engine stopped and did not start again...

When searching for errors, it gave an error in the key, I disassembled it, cleaned the contacts and the error did not appear again, but the car still does not start... I put it in automatic mode until the battery dies, and nothing, the fuel flows but it still does not start...

Any ideas?