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DME RAM Checksum Repair (Cold Weather Stalling Issue) BMW E46 / E83 / E85 / E60

 
Are you experiencing a stalling issue with your BMW that is cold weather related? This is actually a common issue for some older BMW vehicles and is caused by a faulty processor in the DME / ECU (Engine Control Unit). This issue is found specifically the MS45.0 and MS45.1 DMEs which can be found in the BMW E46 3 series years 2003 to 2006, E83 X3 years 2003 to 2006, E85 Z4 years 2002 to 2005, and also the E60 5 series years 2001 to 2004. 

The main symptom of this DME failure you will experience is the vehicle stalling after about 20 to 25 seconds after start up in cold temperatures. 

If you read the fault codes in the DME you will find some or all of the following codes:

  • 2774 -- Engine cut off time
  • 28B2 -- RPM limiting: reset
  • 27A1 -- Electronic throttle controller: start check
  • 2830 -- DME RAM self-test: checksum
  • 2796 -- Electronic throttle controller: adaptation wrong
  • 2869 -- DME Self Diagnostics : RAM-Check Failed
  • 286B -- DME Self Diagnostics : Multi-output Module
  • P16A0 -- Internal Control Module Memory Check Sum Error in Boot Software
  • P16A1 -- Internal Control Module Memory Check Sum Error in Application Software

All of the fault codes above indicate that you need a NEW DME since your processor is now defective, however, Rpm Motorsport is able to repair this issue and offer a 1 Year warranty on this particular repair. This is something we discovered over 10 years ago and so it only felt right to share what we have found to help the BMW community to better understand this frustrating problem. 

You might notice the engine stalling shortly after start up happening randomly once in a while in cold weather (usually below 35 degrees Fahrenheit or around 2 degrees celsius. Usually in the warmer months the car will start and run fine until the temperatures drop again and you are plagued with the same issue again and as time goes on the symptoms may become worse and worse. Before you know it your vehicle is un-drivable in the winter months. 

So what exactly is the issue here and how do we go about repairing it so that the same thing doesn’t happen again in the future you might ask?

Here's a look into how this repair is completed.

Note: Once our work is finished we update the DME to the latest BMW Program Number (Latest Firmware)

Solder left behind on certain components by previous companies that worked on the ECU are professionally cleaned by Rpm Motorsport before we proceed with the repair.

We also make sure that the pins of the motherboard are seamlessly connected, eliminating the possibility of solder pins and joints touching.
Rpm Motorsport takes preemptive measures to ensure that the DME does not go bad again by adding a thermal padding to the processor to ensure it does not get too hot or too cold.
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