Bosch Engine Control Units (ECUs)

Hello,

Recently, someone was selling tuning chips for a 1Z TDI on eBay, and they claimed that all Bosch engine control units with the number 028 906 021 are the same, meaning that all chips for that number are also the same, and that the two letters after the number only indicate whether the chips are soldered or plugged in. However, I find that hard to believe, because if that were true, why are there so many different letter combinations?
Does anyone know anything about that?

Hi,
The person who said that has no idea!
Behind that number, there are at least three different hardware variants of the STG.
- e.g., 028 906 021 B,C: 2 x 8-bit controller and boost pressure sensor up to 2 bar.
- e.g., 028 906 021 P: 2, 8-bit controller and boost pressure sensor up to 2.5 bar.
- e.g., 028 906 021 BF: 1, 16-bit controller, boost pressure sensor up to 2.5 bar.
All three versions are not compatible with each other (although at least the first two use identical processors).
Even with the same engine control unit (ECU) hardware, it cannot be guaranteed that the same (tuning) software will perform equally well in different cars (Golf, Passat, Sharan, etc.), as the software may take into account different characteristics in the engine maps (transmission, weight, etc.).

Thank you for the response. Are there different combinations of letters that are compatible with each other, meaning that the same tuning chips can be used for them?

It depends on how much performance you want to extract from the engine. For a small performance increase, a simple chip swap might be possible (e.g., between a G3 and a Passat). However, the higher the desired performance gain, the more important it is to take your specific car to a tuner of your choice who can precisely tune the chip to your vehicle (rather than just inserting a generic chip).
I am still looking for an overview of compatible software versions myself.

Hello, take a look.
http://www.8ung.at/ecufilechecker/
It might be a start.
'These are only suitable for engines with 110 horsepower.'
I haven't put the others together yet.
You can find the list in the download section.
See you, Thomas.

Hi Thomas,
Thanks for the list.
Let's see what I can do with this.