Mercedes Viano emergency call system malfunction

I had a similar issue with the emergency call system in my old Opel Insignia. Same symptoms: error message, warning light. By 'telematics unit', you mean the system that handles emergency calls and vehicle tracking, right? Did you check all the fuses related to that system? Sometimes it's just a simple blown fuse.

Yes, I mean the unit for emergency calls and vehicle tracking. Thanks for confirming. Where are the fuses located in the vehicle's electrical system? Were there specific diagnostic codes with the fault in your Opel Insignia, and did a system reset fix the problem after the connection issue?

On the Insignia, the fuse box was in the glove compartment and also in the engine bay. Your Viano might be similar. The diagram should be on the fuse box cover or in the owner's manual. I don't remember the exact code, but it was related to the telematics module not communicating properly. A system reset didn't fix it at first; I had to get the connection sorted. If you're not comfortable with the wiring, take it to a workshop. 95€ isn't too bad for peace of mind.

I took it to a qualified technician. It was a faulty connection in the telematics unit, as suspected. After the repair and system reset, the error message is gone, and the emergency call system is working. Thanks for helping me avoid a more costly repair. Your Opel Insignia experience helped a lot.