How to actually "fix" a BMW or Mini Cooper BCM BC1 unit

Posted by Mark Kirschenbaum on

I found it funny that no one has published how to actually "fix" a bad BC1 / BCM Body Control Module in a BMW or in this case a Mini Cooper. In fact, it is fairly easy provided one little part is still working in the original BC1. You also need to find someone that has surface mount soldering skills and a salvaged working BC1. A new one will work, but there is no point! 

Note: We've heard that bad ground points on high current draw components that feed into the BCM can cause similar "strange issues" to occur. This was reported as a bad ground on the wiper motor, but could be caused by a bad ground on any of the components.  


We're simply going to find the serial eeprom and swap it over to a good salvaged unit. It's .150mil SOIC 8 pin IC that stores all the information about the car. A secondary copy of the car's odometer reading, VIN number and other fun stuff is located in this part.   

Microchip EEprom

The part is labeled 93LC76C by Microchip Technology (M) or 93LC763 by StMicroelectronics (ST) and is located on the backside of the BC1 board.


  1. Locate a good salvaged replacement BCM from a car with the same options such as convertible, sunroof etc. I would match part numbers. Searching seemed to work for me in the past.
  2. Remove the plastics from the electronics by gently prying up the retaining clips.
  3. Label the bad unit and the salvaged units very well. It's easy to get parts swapped.
  4. Hot air rework the 93LC76C(3) chip from the salvaged unit. Note, this component is glued down during assembly so it does require a bit of a twist once the solder has flowed. Gently place this on your mat. A hard drop may crack the IC and it's done forever. We are practicing for the real part. Obviously, we also want to be careful not to destroy the pads or other devices!
    If you don't know how to hot air rework circuit boards, this is not the one to start with! The adhesive makes it tricky, the BCM is expensive, and you have one chance!
  5. Let it cool, bag and label the salvaged part. You can also just throw this part away at this time. I like to inspect it under the microscope to make sure my process works well before removing my car's eeprom.
  6. Removed the same part from your "bad" unit. Let is cool. 
  7. Soldered it onto the new "salvaged unit." I would suggest cleaning off the flux and resealing the board with conformal coating. 
  8. Reinstall the plastics and resintall into your car.
  9. Now you bought a new unit and got it programmed for just the cost of a salvaged computer! 

EEprom on MiniCooper BCM
Backside of a BCM

Having us do the swap

If you would like me to swap over these parts with that from a salvaged unit please email me and I will quote a price. Contact information is below. I currently do this swap for $70 USD including shipping in the US (Priority USPS). 

This method should fix the following BCMs: 

61356949288, 61356946363, 61356961364, 61356968827, 61356976989, 61356982115

This only works on 2004(1/2?) to 2008 Mini Coopers. Older models have a different design and are physically potted to the case. 

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