Getting Started with Free/Open-Source PCM Tuning

Instead of spending tons of money buying/licensing one of the proprietery programing setups(and often paying extra per PCM), some great people have made it possible to read/write/tune supported PCMs(P01 and P59 families) using freely available software. For supported PCMs and OSs please see: Operating Systems · LegacyNsfw/PcmHacks Wiki Please note that the list is not all inclusive, there are plenty of our vehicles in those years that are compatible, the most popular one probably being our GM vehicles with the 0411 PCMs.


You will need a computer, some free software, and a compatible adapter.
Here is a list of compatible OBD2 adapters: SupportedDevices · LegacyNsfw/PcmHacks Wiki
I'm using this wifi adapter https://amzn.to/3cFPw53 as it works with both Tech2Win and PCMhammer

To read and write from your supported PCM you will use a piece of software called PCMhammer, available here: Releases · LegacyNsfw/PcmHacks

The second piece of software you will need to actually edit your configuration is the freely available TunerPro: TunerPro and TunerPro RT - Professional Automobile Tuning Software You do not need the RT version.

Basically you will use PCMhammer to read, TunerPro to edit, and PCMhammer to write back to your PCM.

To get started, you have to:

• Download and install the software to your computer
• Plugin/connect your PCMhammer compatible OBD2 adapter.
• Start with PCMhammer and make sure the configuration matches your compatible device.
• Connect your device to the OBD2 port, click on Read Properties inside PCMhammer to determine the Operating System(OS) of your PCM
• Select Tools, Read Entire PCM. This will save your current config to a .bin file Save this somewhere safe so you can always go back to stock. Back it up online, email it to yourself, whatever you need to do but keep this file.
• Open up your favorite search engine and search for the XDF file that matches your OS. This is required by TunerPro to know where the data is stored in your OS.
• The you can open TunerPro and load your XDF and BIN file for editing. Save your edited BIN file for writing to your PCM.
• Using PCMhammer and your adapter again, connect to your PCM and click on Write Calibration choosing your new edited BIN file for writing.

What happens if I can not find the XDF for my OS?

• The easiest solution to that is probably changing to a supported OS on your PCM. Operating Systems · LegacyNsfw/PcmHacks Wiki

Note: if you are successful, please feel free to post your 'Read Properties' results from PCMhammer so others know what all years/PCMs are currently working.

Note: I am not financially/personally involved with any software listed here, it's all available to use free of charge and PCMhammer is open source software. I am simply a happy end user.