4L60E to 4L80E segment swap in HP Tuners

On a Gen III P01 or P59 computer, the segment swap copies the 4L80E's transmission and transmission-diagnostics segments from a stock 4L80E file into your tune, so the computer runs the transmission the way a factory 4L80E truck does. It does not work on a Gen IV E38/T42 setup; that's a T42 flash instead (E38/T42 route).

Last updated November 2, 2026

Before you start

• A VCM Editor version with the Segment Swapper (update VCM Suite if you don't see it), and the vehicle licensed so you can write it.
• Your stock file, read from the computer and saved. Note the operating system (OS) number.
• A stock file from a vehicle that came with a 4L80E and uses the same OS number. For trucks that's usually the 2500-series version of the same truck or SUV.
• A charged battery (don't program below about 11.5 volts).

Step by step

1. Open your stock file in VCM Editor.
2. Open the 4L80E file as a compare file and look at the transmission tables side by side, so you know what's changing.
3. Open the Segment Swapper. Select the transmission segment and the transmission-diagnostics segment from the 4L80E file and import both.
4. Save the result under a new file name, so your original stays untouched.
5. Reopen the new file. Transmission type should read 4L80E, and the shift, line pressure and converter tables should now match the 4L80E file.
6. Running a modified OS (2-bar or speed density)? Do steps 1–5 on the stock file, then open your last good tune as a compare file and copy everything except the two transmission segments into the new file, save again, and do the OS upgrade afterwards.
7. Write Entire.
8. Set gear ratio and tire size, then make your shift and pressure changes in later calibration writes.

Before the first drive

• The harness has to be re-pinned for the 4L80E's input speed sensor and converter clutch: mechanical and wiring steps.
• In the scanner, input shaft speed should read once you're rolling, and gear and converter slip should make sense.
• Engine fires and dies right after the write? You probably swapped onto a modified OS. Redo it from the stock file as in step 6.