Man TGX 440 2012 EEV TCU 1 Error 03155-00: Gearbox Issue Guidance & Details Needed

Hello everyone, I know that sometimes I get this type of error PASSIV TCU 1 03155-00 and I can not take it from what it is, I know something with the gearbox but no one describes the details anywhere, I will only add that it is a MAN TGX 440 2012 EEV and I will be grateful for a hint where to start. I paste a photo

This is an error that describes "gearbox not engaging". There can be several reasons, for example, an ending clutch, an island or the gear activator itself. To solve, you need a fault permanent / deep diagnosis and tests with a diagnostic computer.

Ok, thank you very much, the clutch is 2 years old and we drive mainly on the highways, so I think it's not his fault, maybe the island itself will be checked on the computer on Saturday, the best thing is that this code was lit for the first time, sooner TCU 3 00191- 08, the pracuke gearbox is really flawless. Everyone is surprised that these errors disappear so quickly after a week from the computer's memory, probably when the driver returns on Friday, this error from the island will no longer be there because this TCU 3 00191-08 in diagnoses was not there after 4 days. I fought the NOX sensor and Ad Blue in general, and also on Monday the driver was on fire and I made an appointment for a workshop, and on Saturday in DIAGNOSIS without current entries, what such differences stick and disappear so quickly