Mercedes-Benz S400 Hybrid Won't Start

Mercedes Medic • 2 December 2019

We are working on a 2010 Mercedes-Benz S400 Hybrid that won't start. The problem seem to be with the power module. Since these modules are so hard to find, we hope to be able to find the root cause of the problem so that we can fix this car.

The fault codes present at this time are:

  • U011000 - Communicatin with control unit Electric Machine A has a malfuntion.
  • Communication with control unit Electric machine A has a malfunction - Incorrect data were received.

Both these codes are present and the vehicle will not start.

They seem to point to a faulty power module. Where, what part of the power module has failed is the bigger question.


I got this problem. Twice today at a parking lot. Car wont start. Have to try several times. And wait before it can restart. So far we are at the longest.

  • Log in or register to post comments
  • Update. Wont start again at another store not more than half hour from last incident. Tried to start several times but no luck. Any ideas or is it done. The guy who sold it to me said that there is a small battery on hybrids may need a jump but I dont know the location or if it's TRUE at all. Please advise. Thanks

  • Log in or register to post comments
  • You have jump start terminals in the engine bay passenger side if you want to try jump starting it. If not then you need to read the codes? Also how many miles on yours? 

  • Log in or register to post comments
  • Yes we tried the jump start and nothing just lights on the display. Mine has 47k miles. Good thing it was parked and not on the road. I'm in the USA. Where are you?

  • Log in or register to post comments
  • First I would recommend that you file a vehicle safety complaint. Too many S400 owners are having this problem. File complaint here.

    Second, I would call any Mercedes Benz dealer and ask if service campaign bulletin 2012080004 applies to your car. If your car is part of the campaign they may replace the power electronic free of charge.

    Located in Baltimore MD.

  • Log in or register to post comments
  • That would be helpful. My Vin# WDDNG9FB8AA300627 I'm in Washington State, apparently car was from Canada and I bought the car at MB Motors Llc in Bellingham, WA. They refuse to take the car back.

  • Log in or register to post comments