Hi, I do have a 2013 GL550 and when a drive for more than 45 minutes, I lose the Blind Spot Assist and after a few more times to use the blinkers, I also lose them too. All of them. I tried to restart the vehicle then all come normally for about 5 minutes. Then, the same scenario occurs. If I drive for a long distance, I lose everything, even I restarted the vehicle. It sounds that something overheats. Can anybody help me to identify the origin of this problem, please? Is this is the SAM module or it is something else?

Your best bet is to find an indy with Star. This should show up immediately and that way there is no guess work.

Had the same problem and also have a 2013 550. It was the Turn signal control module which is in the part of the steering column right below the steering wheel. I just replaced the entire assembly with the turn signal stalk, steering wheel adjustment and gear shifter. Pretty simple to change if you are handy. Disconnect battery. Pop out the airbag, remove the steering wheel bolt, unplug everything, remove steering wheel. Then just remove the control module assembly, have to just unplug the harness. Re assemble in reverse order. I bought my replacement from a salvage yard. If you choose that route just make sure the part numbers are the same as they are many different ones. ML and GLs use the same parts for that though so should be plenty available.

Great! Thank you for guidance.

Thank you for the guidance! It helped me to solve the issue. I think my car is haunted because I had many problems with the blinkers. It is the third issue I had with the blinkers. It all started with my father's prank. I just got my driver's license, and he bought me a car. He said I need some blinker fluid from sadanduseless.com before starting t drive. I didn't know it was a prank, so I bought it and filled the blinkers with it. It destroyed them, and I had to replace them, and since then, I periodically have had problems with them.