Ford Mondeo Mk4 2.2 engine failure?

For a short time now, I have repeatedly been shown an engine fault in my conversation. Mostly when driving slowly / normally. The error never occurs when driving faster on the freeway.

The fault remains for a few seconds and disappears again.

Fault memory is empty… Had the laptop connected while driving and at the moment when the fault came it was read without success.

The car runs without problems

The supply line for the signaling of the error could occasionally get a short circuit, so that where else plus 12 V is present.
If you drive slowly, the car vibrates more so that this apparent mistake comes more often. The car is quieter at higher speeds.
Check the wiring (wiring harness) to this display