Hi All. Has anyone experienced this issue with a Fiat 500 Dualogic as its driving me crazy- Gearbox works 100% when driving -all gears select no problem at all But with engine running when I select neutral it wont- message on dash warns you that its not possible- cannot get neutral from reverse either. If i switch engine off and just have ignition everything works fine, but as soon as engine is running No Neutral unless you default it by going from a forward gear to reverse without foot on brake.
So far i have replaced -brake switch, gearbox clutch speed sensor and tried a secondhand tcm and gear lever. No fault codes in any system
Any help appreciated

Welcome, I'd say, if its OK when driving normally, leave it alone, use your work around, see this thread https://www.fiatforum.com/500/425006-one-only-dualogic-failure-thread.html

Have you checked the rear brake lights (and the light cluster earths)?
And the tailgate wiring?
Both can cause this, but are easy to overlook.

All rear brake lights work, but have not checked the earths- will do and respond. Thx

Came across this today https://youtu.be/-g7teDU2Jm8 may have no relevance at all but your gearbox issue jogged my memory (hatch wiring)

Thx but not same issue- in fact this is so opposite to what Fiat 500 dualogics famously do. I will have to pin out signals from engine ecu to transmission ecu to get to the bottom of it- me thinks !!