Illustrated donor guide
How to match BMW DME donor part numbers
Use the manufacturer number, DME family, and hardware revision or index as the primary donor identity. Confirm the BMW number and complete label before buying.
Siemens / Continental example
- Manufacturer number: 5WK90027
- DME family: MS43
- Hardware revision: Index 09
- BMW number: 7 551 615
Safest donor target: 5WK90027 + DME MS43 + Index 09. Use 7 551 615 as supporting confirmation.
Other numbers could be seller or inventory sticker. Do not use it to select your donor ECM/DME. The best practice is to match the numbers of your original DME.
Bosch example
The complete Bosch number in the red box is 0 261 S14 562. You need to match this number when searching. It is also a good practice to confirm the BMW number matches, in this case 8 655 428-01.
Why an exact hardware match is preferred
Some controller families can be cloned across more than one part number or hardware revision, but that is not a guarantee and it is not reliable. We have had problems when mixing and matching so we stopped doing it.
With BMW, the rule is simple: buy the exact match when available.
Do not substitute another ECU family
An MS42 or MS45 is not an MS43 donor merely because the aluminum case and connectors look similar. The same principle applies to later Bosch, Siemens, and Continental families.