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Mercedes donor ECU guide

How to match Mercedes ECU part numbers

Find a usable Bosch, Siemens/Continental, or Delphi replacement engine computer without guessing from the vehicle description or connector shape.

Mercedes Bosch ECU label showing the Mercedes-Benz and Bosch part numbers that must match
Bosch example: match A 272 153 60 91 and 0 261 209 284 exactly. Spaces do not matter; every digit does.

The short answer

Shop by year, model, and engine to find possible donors, but buy by the complete labels. A compatible-looking used ECU can still be the wrong hardware revision. Ask the seller for a clear photograph of the entire label before paying.

Bosch Mercedes ECU labels

  • Match the complete Mercedes-Benz A-number exactly.
  • Match the complete Bosch number exactly.
  • Confirm the controller family, such as ME9.7, ME2.8, MED17.7, EDC16, or EDC17, when possible.

In the example above, the Mercedes number is A 272 153 60 91 and the Bosch number is 0 261 209 284 and this is a ME9.7. If this was your original ECM, you want to purchase a donor that matches those numbers.

Siemens and Continental labels

  • Match the primary Mercedes-Benz A-number.
  • Match any separate Mercedes hardware number marked HW or shown as another A-number.
  • Match the complete Siemens/Continental 5WK or A2C number.
  • Match the complete controller family and subtype, not merely “SIM271.”

SIM271DE and SIM271KE describe different controller paths. Do not assume that a similar case, connector, or M271 engine description makes them interchangeable.

Delphi CRD labels

  • Match every Mercedes-Benz A-number printed on the labels.
  • Match the complete Delphi R-number or eight-digit 28-series number.
  • Match the complete CRD designation, including the suffix: CRD.11, CRD2.xx, CRD3.10, CRD3.20, and so on.
  • Confirm the same engine and injector application.

“OM651 ECU,” “Sprinter computer,” or simply “CRD3” is not specific enough to order a donor safely.

Finding a donor through Car-Part.com

Car-Part.com searches inventory from automotive recyclers and is often a better first stop than eBay for a used original ECU.

  1. Choose the Mercedes year and model.
  2. Select Computer Box, Engine in the part drop-down.
  3. Enter your ZIP code and choose a search radius.
  4. Review the recycler notes, price, location, and warranty.
  5. Call or message the yard and request a complete label photograph, or give them yours and ask if they have a match.
  6. Some yards use an “interchange” system to tell them what parts fit. This is not a fender, we recommend to match the numbers for the highest odds of compatibility and a successful clone.
  7. Match the label numbers using the rules above before buying.

Car-Part.com says its search has interchangeability built in using Hollander Interchange. That can identify likely candidates, but the site also advises buyers to contact the recycler to verify the part. For cloning, the ECU labels are the key to success.

Numbers that do not replace the hardware match

A production date, serial number, barcode, software number, or seller interchange number may help identify the unit, but they are not substitutes for the matching manufacturer and hardware identities above.

Ready to have the donor cloned?

After you have the original and a correctly matched donor, order the Mercedes ECU / ECM engine computer cloning service. Clone-only service is $299 with tracked standard US return shipping included.