Mercedes B Klasse Electric Gearbox Issues Resolved

It sounds like you are experiencing a rather unfortunate set of transmission problems with your Mercedes B Klasse. The symptoms you describe, particularly the inability to shift with the paddles, the slipping, the grinding noises, and the emergency mode activation, strongly suggest a potential issue with the transmission control unit, as you suspect. Has the error memory been read? If so, what specific error codes are present? Knowing the exact codes will help to confirm the diagnosis and perhaps point to related issues. What is the response of the gearbox like when using the gear stick?

The error memory was read, yes. It points to a defective transmission control. Shifting with the gear stick is also not smooth, but it is better than the paddle shifters. What are the next steps to take?

Given the error code indicating a defective transmission control and the persistent symptoms, it appears quite probable that the control module is indeed the root cause of your automatic gearbox woes. Further diagnostics, such as checking the wiring harness and connections to the control unit, could be performed, but given the symptoms, it may be a waste of time. Based on this information, I would recommend taking your vehicle to a qualified workshop to have the transmission control unit replaced. Be prepared for a repair bill in the region of 1000€, including parts and labour.

Thanks for the confirmation. I took it to the workshop. They replaced the transmission control unit and that fixed the problem. Cost me around 1000€ as you predicted.