Instrument cluster not working

2012 MERCEDES BENZ C250
80,000 MILES • 6 CYL • AUTOMATIC
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CHRISTIANA
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Woke up this morning to a very foggy day and an instrument cluster completely blank. Everything else seems fine in the car, most function works besides the steering wheel buttons.

I'm also unable to access my information or time on the COMAND. Lastly I'm having some issues with my key fob not unlocking the doors consistently although not sure if its related since I haven't replaced the key battery since I got the car.

I've checked all fuses and they're fine. Battery was replaced about 2 months ago and had my last service done about 1 month ago. Usually when my battery goes bad my power windows and SRS fails.

Battery was completely unrelated, fixed with battery change. I've ordered a new Instrument Cluster and will replace as soon as I get it. Any and all ideas in the meantime are welcomed.
Nov 30, 2019 at 2:16 PM
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STRAILER
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Hello,

Can you check for power at fuse # 18 and 28 in the front SAM control unit? Here is a guide to help us with the instrument cluster wiring diagrams so you can see how the system works:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.
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Dec 2, 2019 at 11:07 AM
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CHRISTIANA
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Hey Ken, thank you for the reply.

I unplugged the battery and waited for 5 minutes. The instrument cluster stayed dead. The morning after the instrument cluster worked for about 30 minutes for it to die mid drive.

I used my OBD just to find out that it didn't work. I replaced the OBD fuse which seemed good and my OBD showed me the fault that the instrument cluster failed to connect (paraphrasing here).

I took the instrument cluster out and after putting back on the instrument has worked without any issues.

I'll check the SAM if the instrument cluster goes out, thank you.
Dec 4, 2019 at 2:45 AM
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STRAILER
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Yep sometimes unplugging them and plugging them back in can correct a bad connection at the cluster. Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.
Dec 4, 2019 at 1:03 PM