This release is obsolete.

Please use the latest release instead.

This release fixes in-vehicle reflashing with the ObdLink ScanTool LX (and probably MX/MX+).

This release also includes a new data logging app, PCM Logger. It basically works, and in future releases it will become easier to use.

There are three known issues, both of which are expected to be fixed soon:

1. Write Parameters (Clone) is disabled due to risk of data corruption.
2. For the P59 PCMs (aka 1mb PCMs), calibration writes are supported, but full OS writes are not.
3. Calibration writes won't work on 1mb PCMs with Intel flash chips. This is fixed in release 10.

One warning:

Please don't make OS or calibration changes in your only car. This is new software, and you'll be among the first people in the world to use it. If something goes wrong, it may be a while before you drive that car again.

Reading and data logging are perfectly safe, though.

To use this stuff, unzip all of the files into an empty directory, and run PcmHammer.exe or PcmLogger.exe. When the window appears, the first thing you'll need to do is select the device that you're using.

To test PCM Hammer, click Read Properties to confirm that you've selected the device correctly - it should print a few details about your PCM. Then try "Read Contents." And then, if you're feeling bold... and if you have a different car that you can use to drive to work... try writing the calibration or parameter blocks.

To test PCM Logger, open a log profile and click "start logging." To create your own log profile, open one of the examples in notepad.exe and... well, you're on your own. As noted above, this will get easier in future releases. If you come up with something useful in the meantime, please share at http://pcmhacking.net/ .

This project is still in its early stages. You may encounter bugs. The software may behave in strange ways. Please report such things to us so that we can fix them.

If anything goes wrong, please take detailed notes about the exact steps that you took, and please also copy the contents of the Debug tab and save it to a file. We'll need that to figure out what went wrong, how to fix it, and how to prevent it from happening to anyone else.

The developers can be reached by creating a new thread at pcmhacking.net: https://pcmhacking.net/forums/viewforum.php?f=42

While we think it is just about impossible for this software to make your car unusable, please keep in mind that we're just a bunch of hobbyists who have been working on this stuff in our spare time. It's a miracle that we've gotten this far. If you need the guarantees that come with a commercial product, you should buy a commercial product.

This release is obsolete. Please use the latest release instead.

This release added the ability to write to the calibration and parameter blocks of P59 PCMs (also known as the 1mb PCMs). However it contained a bug that prevented the ScanTool family of devices from working well when used in a vehicle. They did still work for workbench reflashing though.

This release added the ability to completely replace the contents of flash memory of GM's P59 PCMs (aka 1mb PCM).

Except that you can't read from a P59 using this release, which is rather important. You definitely want to do that before you write.

So, let's pretend this release never happened. A new release is coming very soon.

This release is obsolete. Please use the latest release instead.

This release added the ability to completely replace the contents of flash memory for P01 PCMs (aka the 512kb PCMs).

This release is obsolete. Please use the latest release instead.

This was basically just release 4 with a few minor changes to make everything more reliable when using AVT's interfaces.

This release is obsolete. Please use the latest release instead.

This is (was) the first release that will allow you to read and write the contents of a General Motors '411 Powertrain Control Module (PCM). While the read feature will read the entire contents of the PCM, the write feature is currently (was) limited to the calibration and parameter sections.

This release is obsolete. Please use the latest release instead.

With this release, P01 calibration writes were supported, but it was up to the user to ensure that any changes you apply to a PCM are compatible with the operating system that is currently on that PCM. In later releases, the app will prevent you from flashing incompatible changes.

This release is obsolete. Please use the latest release instead.

The only change from the previous release is that this version fixed support for J2534 interfaces.

This release is obsolete. Please use the latest release instead.

This first release of the PCM Hammer utility allowed you to read the contents of a General Motors '411 Powertrain Control Module and save it to your computer as a .bin file.

We added write functionality in a subsequent release.

Just some utilities, nothing for end users yet.