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A problem that Mercedes-Benz S-Class W221 owners may experience is the backup camera stops working when the transmission is placed in reverse. The COMAND screen shows a blue screen and guidance lines but no image. 

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This problem can affect 2006-2013 W221 models such as S350, S400, S450, S550, S63 AMG, S600.  


  • Blue screen 
  • No image when backing up
  • Check entire surroundings shows up but no camera image.


mercedes benz blue screen due to bad comand head unit

In most cases, this problem is intermittent and typically happens in the morning when very cold. The problem goes away when the engine warms up or on warmer days. 


  • Blue Screen - If the problem is intermittent and worse when it is cold, then it is likely that this problem is caused by a faulty resistor inside the head unit. 

If the backup camera has stopped working completely regardless of exterior temperature, then the problem may not be the resistor inside the head unit but a damaged camera or wiring harness. 

  • Black Screen - If the screen is black, the problem can be due to a broken camera wire. The camera wire breaks at the trunk left (driver side) hinge. Remove the panel and inspect the wire at this location for damage. Solder the wire if it is broken. 


To fix the resistor problem, you will need to replace or repair the COMAND head unit. The most expensive solution is to remove and replace the head unit with a new one. This method can cost between $800-$1200 at most Mercedes-Benz dealerships. 

A less expensive solution ($350-$500) is to remove your old head unit and send it to a Mercedes-Benz specialist for repair. There are a few places that fix Mercedes-Benz command units, but you will need to ship them to them for repair.

At the time of this listing, we could find W221 Comand Repair Service on eBay. The turnaround time is typically between five to ten days.