ESP firmware has two components:

- Firmware file (.HFMP): This is the firmware component that lives inside the ECU.

- Definition file (.HDEF): This tells the ESP software how to speak to the firmware.

If you are trying to connect to an ECU, you will only need the definition file. The firmware will be extracted from the ECU during connection.

Definition packs can be found on our website, under Downloads > ESP ECU Firmware. Save the ZIP file, then extract to /Documents/Haltech/Definitions.

Note that first launch of ESP after adding the definition pack will take longer than usual, while the software checks all new files.

If you have any issues adding files, or if the required definition isn't included in our download pack, please contact Haltech support: