2024–2026 L5P Duramax Breakdown

2024–2026 L5P Duramax Care Package Breakdown

STEP 1 — Purchase Your Care Package

Once your order is placed, we'll email you requesting your vehicle information (VIN, modifications, transmission information, etc.) so we can build your custom tuning.

CARE PACKAGE

STEP 2 — Send Us Your Factory ECM

Your original factory ECM must be removed from the truck and shipped to us.

Important:

  • Must be your original ECM

  • Spare ECMs cannot be used

  • ECM must not have broken tabs or connectors

  • ECM must be fully functional before being unlocked

STEP 3 — ECM Unlock Process (2–4 Weeks)

Once we receive your ECM, it is sent out for the unlock service.

Current turnaround:
 Approximately 2–4 weeks

Unfortunately this process cannot be expedited.

During this time your truck will remain down while the ECM is away for unlocking. HP Tuners' Global B support for 2024+ trucks requires an upgraded/unlocked ECM before custom tuning can be written.

STEP 4 — TCM Unlock (Required for Transmission Tuning)

If you purchase transmission tuning, your TCM must also be unlocked.

Engine tuning and transmission tuning are two separate control modules.

No unlocked TCM = No transmission tuning.

TCM UNLOCK AND TUNING SERVICE 

STEP 7 — Reinstall the ECM

Once your unlocked ECM arrives back:

  • Install the ECM

  • Reinstall the battery connections

  • Verify the truck starts properly

STEP 8 — Read Your Stock File

Once you receive your unlocked ECM (and TCM, if applicable) back in the mail:

  • Reinstall the modules into your truck.

  • Using your HP Tuners MPVI interface, perform a stock read of your ECM (and TCM if transmission tuning was purchased).

  • Email the stock read file(s) to our tuning team.

We use your stock read to verify the unlock was successful and build your custom calibration specifically for your vehicle.

Please do not flash any tuning until we have received and reviewed your stock read file(s).

STEP 5 — We Build Your Custom Files

Once your unlocked ECM (and TCM, if applicable) return:

  • Your custom engine tuning is built

  • Your transmission tuning is built (if purchased)

  • Your tuning files are assigned to your truck

  • Everything is prepared for installation


STEP 9 — Flash Your Custom Tuning

Using your HP Tuners interface, you'll flash your custom calibration onto the unlocked ECM.

If you purchased transmission tuning, you'll also flash the TCM calibration after the TCM has been unlocked.

STEP 6 — Install Your Parts

DO NOT INSTALL PARTS UNTIL TUNING IS COMPLETED 

  • Exhaust

  • Downpipe

  • EGR components

  • Turbo gaskets 

  • Other selected upgrades

STEP 10 — Enjoy Lifetime Support

Every JAT Care Package includes:

  • Lifetime engine tuning updates

  • Revision support

  • Future tune changes (within your package)

  • Technical support whenever you need it

Frequently Asked Questions

Can I keep driving my truck while the ECM is being unlocked?
 No. Your factory ECM must be removed, so the truck will be down during the unlock process.

Can the unlock be rushed?
 No. The unlock service currently takes approximately 2–4 weeks and cannot be expedited.

Do I need the TCM unlocked?
 Only if you purchased transmission tuning. Engine tuning and transmission tuning are separate systems.

Why does it take so long?
 The 2024+ Duramax uses GM's newer Global B architecture, which requires the factory ECM to go through a specialized unlock process before custom calibrations can be written.




2024–2026 L5P Duramax ECM/TCM Unlock + Tuning Only

What You'll Need

To tune your 2024–2026 L5P Duramax, you'll need the following:

1. ECM/TCM Unlock Service

Your factory ECM must be unlocked before custom engine tuning can be loaded.

If you plan on adding transmission tuning, your TCM must also be unlocked.

Engine Tuning = ECM Unlock Required
 Transmission Tuning = TCM Unlock Required

ECM UNLOCK SERVICE 

TCM UNLOCK SERVICE 

 

 

2. Custom Tuning Service

Once your unlocked module(s) are returned and you've provided us with your stock read file(s), we'll build your custom tuning specifically for your truck.

Choose from:

  • Engine Tuning

  • Transmission Tuning

  • Engine & Transmission Tuning

ECM TUNING SERVICE 

TCM TUNING SERVICE 

 

3. HP Tuners Interface (If You Don't Already Have One)

An HP Tuners MPVI interface is required to:

  • Read your stock ECM/TCM files

  • Email the stock read file(s) to us

  • Flash your completed custom tuning

If you do not already own an HP Tuners interface, you'll need to purchase one before you can complete the tuning process.

HP TUNERS DEVICE