DO NOT turn the ignition on or place the truck into Service Mode while the ECM is removed from the vehicle.

The 2024–2026 L5P uses GM's Global B electrical architecture. Keying the truck on without the ECM installed can cause an immobilizer issue that may require an immobilizer relearn.

Install the unlocked ECM before turning the ignition on.

A few things should be taken care of before reading or programming the truck:

1. Disable Apple CarPlay or Android Auto on the phone or tablet being used for tuning. These can interrupt the connection during the process.
2. Make sure you have a fast and stable internet connection, either cellular or Wi-Fi, that reaches the location where the truck will be programmed.
3. Do not install modified parts before installing the tune file. These trucks are very sensitive to changes in vehicle configuration, and any aftermarket parts need to be accounted for in the tune.
4. Make sure the truck's batteries are properly charged before beginning.
5. If transmission tuning is being performed on a truck equipped with the T93 Global B TCM, the TCM must first be removed and sent in for its required mail-in unlock. Do not attempt TCM tuning before the unlock is complete.
6. Once we receive your stock read, there may be approximately 2–3 business days of processing time before your tune is added to your account.

Once your unlocked ECM has been reinstalled and you have received your MPVI4 or RTD4/SFG Tuner, download the HP Tuners TDN App.

Android

Download TDN for Android

Apple / iPhone

Download TDN for iPhone

Initial Setup

1. Install and open the TDN App.
2. Follow the on-screen prompts for the license agreement and First Time Setup.
3. The setup process will require you to connect the MPVI4 or RTD4/SFG Tuner to the truck's OBD-II port.
4. Follow the on-screen instructions to pair your phone or tablet with the tuning device.
5. If you do not already have an HP Tuners account, create one from the Account page in TDN.
6. If you already have an HP Tuners account, sign in.
7. Once signed in, return to Account.
8. Select Link Tuner.
9. Enter tuner link code:

JGVD-8122

10. Contact us and let us know that you have submitted the link request.

TDN does not automatically notify us that you have requested access. We must manually approve the link before you can proceed with your stock read.

Do not begin this process until your tuner link request has been approved.

1. Connect the MPVI4 or RTD4/SFG Tuner to the truck.
2. Open the TDN App.
3. From the TDN home screen, select Flash.
4. At the bottom of the Flash screen, select Read Vehicle.
5. Place the truck into Service Mode.

For push-button trucks:

• Keep your foot OFF the brake.
• Press and hold the Start/Stop button.
• Continue holding it until the light on the Start/Stop button is solid green.
• The engine must NOT be running.

6. Begin the vehicle read in TDN.
7. TDN will query the vehicle.
8. The app will then instruct you to turn the ignition OFF.
9. Turn the ignition off as instructed.
10. Press OK in TDN.
11. TDN will transfer the required information to the HP Tuners servers.
12. The app will then instruct you to turn the ignition back to RUN, with the engine off.
13. Again, with your foot OFF the brake, press and hold the Start/Stop button until the light is solid green.
14. Press OK in TDN.
15. Allow the app to finish the read process.

The stock vehicle information will now be uploaded through TDN.

Contact us and let us know that the stock read has been completed.

We will use the uploaded information to prepare the tune for your specific truck.

Once your tune is complete and uploaded, you will receive notification that a new tune file is available.

Once you have been notified that your tune is available:

1. Connect the MPVI4 or RTD4/SFG Tuner to the truck.
2. Open the TDN App.
3. Select Flash from the TDN home screen.
4. Select Sync Files.

TDN will download the available tune files from the server to your tuning device.

5. Wait until the file synchronization has completely finished.
6. A green check mark will appear beside files that have successfully synchronized.

The file named Restore is your stock calibration.

7. Make sure the truck's batteries are charged.
8. Place the truck into Service Mode, with the engine NOT running.

For push-button trucks:

• Keep your foot OFF the brake.
• Press and hold the Start/Stop button until the light is solid green.

9. Select the tune file you want to install.
10. TDN will display CANCEL and WRITE.
11. Press and hold WRITE.
12. Select Write Entire.
13. Allow TDN to begin the programming process.

The app will go through several preliminary stages, including processing, gathering information, and querying the vehicle.

14. Once those steps are complete, TDN will instruct you to turn the ignition OFF.
15. Turn the ignition off.
16. Press OK in the app.

The truck will now begin programming.

Do not disconnect the tuning device, close the TDN App, interrupt vehicle power, or attempt to start the truck while programming is in progress.

The actual write process is normally fairly short, but allow TDN to complete every step before doing anything with the vehicle.

17. Once programming is complete, TDN will instruct you to place the ignition back into RUN, with the engine off.
18. With your foot OFF the brake, press and hold the Start/Stop button until the light is solid green.
19. Press OK in the TDN App.
20. Allow TDN to complete its final checks.

Programming is now complete.

Check the truck for any new warning messages or faults before driving.

If new faults are present after programming, contact us before driving the vehicle.

If no new faults are present, you may install the aftermarket parts that were accounted for in your tune.

Do not drive the truck using a tune that was not made for its current hardware configuration. Running the vehicle with parts or tuning that do not match can cause drivability problems or mechanical damage.

If you change the vehicle configuration later, contact us before operating the truck under load so we can determine whether the tune needs to be updated.