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The software trw2scan is the only freely available tool being able to communicate with airbags ECUs using the TRW2 protocol. This kind of ECUs is found in many cars built by Fiat until the late 90s (Fiat, Alfa Romeo, Lancia,...).

The software is used together with script files that define the communication details that are different from car to car.

The usage syntax is:

trw2scan scriptfile


trw2scan works with USB KKL-adapters based on FTDI's FT232 chip. There are many sources found on the web, one is stated below.

Airbags should be replaced by 3.3Ohm "dummy" resistors for safety reasons in order to prevent the ECU from detecting the missing airbags. For disonnecting the airbags follow the workshop manual!

To be able to connect to the GTV ph 1 (ECU 60625181) the L-line must NOT be connected. You need to modify either your KKL-adapter or the OBD2 16-pin to Fiat 3-pin adapter cable for this purpose.

ECUs known to be supported

ECU number Cars
60631206 Alfa 145/146
60625181 Alfa GTV phase 1 (Make sure L-line is not connected!)
Alfa Spider 916

Safety Issues

ATTENTION: It is strongly recommended NOT to use this software while the airbags are connected to the ECU! For disconnecting follow the procedure proposed in the respective workshop manual. E.g. disconnect the battery and wait for 10 minutes before disconnecting the airbag.


Working on car electronics may cause severe damage and danger and has to be done by qualified personnel using qualified equipment and software.

trw2scan is no qualified tool suited to perform car repairs. The software is intended only for educational purposes demonstrating on board diagnosis protocols. The usage together with devices that are connected to car electronics or airbags is not recommended. The software is provided "as is" without warranty of any kind. Any liability for damages caused by using the software is excluded.


trw2scan download page

Homepage of the unidiag OBD software, also providing a KKL-adapter compatible with trw2scan

Video demonstration of how to use trw2scan

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