General Motors Online Checksum Calculator

This online checksum calculator allows you to correct the checksum for General Motors calibration files after a file modification, which can be used with the GM DPS software tool to program custom code into the modules.

To begin, follow these three steps:

1. 1. Select the original file to determine the calculation method (Big Endian or Little Endian, 16-bit only).
2. 2. Next, choose the second file for which you need to correct the checksum.
3. 3. Finally, download your file with the corrected checksum.

**Important**

• 1. Both files must be unzipped before use.
• 2. The first file should be the original version of the second file.
• 3. If the checksum in the first file is incorrect, the checksum for the second file cannot be corrected.