Table of Contents

Quick Answer: Look Up Your Truck

Find your platform and model year below for a fast answer. If your truck is not listed or you are unsure which engine or transmission you have, send your year, make, model, engine, and cab and bed configuration to support before ordering.

Platform Model Years ECM Unlock Needed Typical Fix
Ram 6.7L Cummins 2019-2024 Yes EZ Lynk AMDP tuning package plus SOTF switch
Ram 6.7L Cummins 2007.5-2018 No EFI Live or handheld tuner works without an unlock
Duramax L5P 2017-2023 Yes EZ Lynk AMDP tuning package plus CAN bus connector
Duramax LML, LMM, LBZ, LLY, LB7 2001-2016 No Standard EFI Live custom tuning
Ford 6.7L Powerstroke 2011-2019 Generally no SCT or EZ Lynk tuning without a factory unlock
Ford 6.7L Powerstroke 2020-2024 Depends on PCM EZ Lynk AMDP tuning package, confirm PCM before ordering
Jeep and Ram EcoDiesel 3.0L 2014-2023 Limited tuning support Confirm tuner compatibility with support before buying

This table covers the platforms EngineGo carries parts for most often. Fitment can shift within a model year on some trucks because of mid-year PCM changes, so treat this as a starting point and confirm before checkout.

What a Locked ECM Actually Is

The engine control module, or ECM, is the computer that manages fuel delivery, boost, timing, and emissions-related functions on your diesel. On older trucks, that computer accepted custom tuning files from almost any tuner without restriction. Starting with certain model years, manufacturers began encrypting ECM and PCM firmware so it only accepts calibration files that come from an authorized source.

Why Manufacturers Started Locking Them

The locking was introduced primarily to control warranty claims, prevent unauthorized emissions tampering at the dealer level, and reduce liability tied to aftermarket tuning on trucks still under factory coverage. It was not designed with the aftermarket delete and tuning community in mind, but it directly affects anyone trying to install a diesel tuner on an affected platform.

What Happens If You Try to Flash a Locked ECM

If you attempt to load a standard tuning file onto a locked ECM, the flash will typically fail, throw an error, or in some cases leave the truck unable to start until the calibration is corrected. This is one of the most common support calls diesel shops get from owners who bought a tuner without checking fitment first. Confirming your exact platform before you order prevents a truck sitting in the driveway over a mismatched part.

Platforms That Require an Unlock

2019+ Ram 6.7 Cummins

Ram switched to a locked PCM architecture starting with the 2019 model year 6.7L Cummins, covering the 2500, 3500, 4500, and 5500 trucks. On these trucks, a standard EFI Live cable or handheld programmer will not communicate with the ECM until an authorized unlock has been completed. Most 2019-2024 Cummins owners run an AMDP EZ Lynk custom tuning package paired with a start-over-the-flash switch, listed here as the EZ Lynk AMDP SOTF switch, to get the unlock and the custom calibration in the same purchase. Trucks built with the Aisin transmission have their own tuning requirements, covered by the Aisin transmission tuning package. Browse the full lineup on the 6.7 Cummins tuner collection or shop by exact fitment on the 2019-2024 Ram 6.7 Cummins vehicle page.

For a deeper walkthrough of what changed on this generation, read our 2019 Ram 2500 6.7L Cummins ECM unlock and tuning guide.

2017+ L5P Duramax

The L5P Duramax, used in 2017-2023 Chevrolet Silverado and GMC Sierra 2500HD and 3500HD trucks, also runs a locked PCM. Owners typically need an EZ Lynk AMDP tuning package for 2017-2019 L5P or the 2020-2023 L5P tuning package, along with a CAN bus connector such as the L5P CAN bus connector, 2017-2019 or the 2020-2023 CAN bus plug connectorao/products/2017-2019-6-6l-l5p-duramax-ez-lynk-custom-amdp-tuning-package-PTN0240AZZ. Confirm your build year before ordering, since the connector and tuning package differ between the earlier and later L5P production runs. Shop the full range on the L5P Duramax tuner collection.

If you are pairing the unlock with a delete kit, our L5P Duramax delete kit buyer guide covers how the tuning and delete components work together.

Late-Model Powerstroke Considerations

Ford has not locked the 6.7L Powerstroke ECM as broadly as Ram and GM, but 2020 and newer trucks can carry updated PCM hardware that changes tuning requirements depending on build date. Owners of 2011-2019 trucks typically tune without an unlock using the 6.7 Powerstroke tuner collection, while 2020-2024 owners should confirm PCM compatibility before ordering. AMDP EZ Lynk packages are available for both ranges, including the 2011-2019 F250 and F550 tuning package, the 2020-2022 tuning package, and the 2023-2026 tuning package. Trucks running an SOTF switch use the AMDP SOTF switch for 6.7 and 3.0 Powerstroke.

Platforms That Don't

Not every diesel truck on the road needs an unlock. Pre-2019 Ram Cummins trucks, all Duramax generations before the L5P (LB7 through LML), and most 2011-2019 Powerstroke trucks tune with a standard EFI Live cable or handheld programmer without any additional unlock step. If your truck falls into one of those windows, you can move straight to selecting a tuner from the full tuner collection without budgeting for an unlock service.

EcoDiesel owners should check compatibility carefully. Tuning support on the 3.0L EcoDiesel is more limited than on the big three platforms, and not every year has the same tuner options available.

How the Unlock Process Works

Mail-In vs Bench Service

Most EZ Lynk AMDP unlocks are handled remotely rather than requiring you to physically ship the ECM. You install the tuning device in the truck, connect it to a laptop or the vendor's software, and the unlock and initial calibration are pushed through that connection. A small number of older locked platforms still use a bench service, where the ECM is removed and sent out, but this is not the standard path for the Cummins and Duramax platforms covered above.

What You Ship and How It Comes Back

If your specific build does require a bench unlock, you typically ship only the ECM or PCM, not the full engine harness. It comes back reflashed and ready to reinstall, along with any documentation needed to keep the unlock active on future tunes.

Typical Turnaround Time

Remote unlocks completed through the tuning device are usually finished the same day once the device is registered and connected. Bench-service unlocks, where required, generally run several business days once the module is received, not counting outbound and return shipping.

Truck Downtime: How to Plan For It

For most owners, the truck is drivable while a remote unlock and initial calibration are completed, since the process happens through the OBD port rather than requiring disassembly. If your platform needs a bench-service unlock, plan for the truck to be down for the shipping window plus processing time. Order your tuning package and any required delete components together so you are not waiting on a second shipment before the truck is back on the road.

Cost: Unlock, Tuner and Tunes

Pricing depends on the platform and whether the unlock is bundled into a tuning package or purchased as a separate service. On the platforms covered in this guide, the unlock is built into the AMDP EZ Lynk tuning package price rather than sold as a standalone line item, so you are paying for the tuner, the unlock, and the initial custom tune together. SOTF switches and CAN bus connectors, where required, are typically sold separately from the tuning package itself. Check the product page for your exact year and engine to see what is included before you check out.

Is It Reversible?

An ECM unlock itself does not need to be reversed to restore factory-style operation. Most AMDP EZ Lynk packages allow you to load the stock calibration back onto the truck at any time through the same device used to install the custom tune, which is useful if you are selling the truck or returning it closer to factory settings.

Buying Order: Unlock First or Kit First?

For the platforms listed above, order the tuning package first, since it typically includes the unlock and the base calibration your delete or performance parts will need to run correctly. If you are planning a full setup, review our guide on whether you should tune if you choose to delete your truck before finalizing your parts list, and check what it means to delete and tune a diesel truck if you are new to this process. Cummins owners specifically can also review 6.7 Cummins delete tuner best options for 2013-2024 for a platform-specific breakdown.

Legal Notice: Off-Road and Competition Use Only

Emissions-related tuning and delete products discussed in this guide are intended for off-road, race, or non-public-road use where permitted. Customers are responsible for confirming compliance with federal, state, and local laws before purchase and installation. EngineGo does not represent these products as legal for use on public roads on emissions-controlled vehicles unless specifically stated and verified.

Frequently Asked Questions

How do I know if my truck's ECM is locked?

Check your exact model year against the lookup table above. If your tuner installation fails to communicate or throws a lock-related error, that generally confirms a locked module.

Can I unlock the ECM myself?

The unlock process is completed through the tuning device and its associated software rather than performed manually, so no separate DIY unlock step is required beyond installing the tuning package correctly.

Will an ECM unlock void my factory warranty?

Tuning and delete modifications can affect warranty coverage on emissions-related components. Review your specific warranty terms and consider your truck's warranty status before proceeding.

Do I need the unlock even if I am only installing a delete kit and not tuning for performance?

Yes. On the platforms listed as requiring an unlock, the ECM must be unlocked before any custom calibration, including a delete-specific tune, will load correctly.

What if my truck's exact PCM does not match the years listed here?

Send your year, make, model, engine, and cab and bed configuration to EngineGo support before ordering so we can confirm the correct tuning package for your build.