The 2024–2026 L5P All-In-One Kit Dieselr is the most complete tuning package available for GM’s latest 6.6L Duramax trucks equipped with the new E42 ECM. Built by techs, tested on real trucks, and packaged for results — this kit gives you everything you need to tune your L5P the right way.

Optional Upgrade — Transmission Tuning Support

This All-In-One Kit supports engine tuning out of the box. You can now complete the system by adding TCM tuning, which integrates cleanly and allows engine and transmission calibration to work together as intended.

To add TCM tuning, the following components are required:

GM T93 TCM Upgrade Service (Required - factory TCM send-in)
Dieselr T93 TCM Tune Files
(4) HP Tuners Universal Credits (sold separately)

This upgrade is optional, but recommended for customers who want full control and consistency across both engine and transmission tuning.

Add TCM Upgrade Service (Required for Tuning) Add TCM Tune Files Add Required Credits (4)

At the core is the HP Tuners RTD-4 paired with one of Dieselr’s custom Upto +180HP single-level tune files — VIN-matched, dyno-tested, and built for safe torque, better throttle response, and reliable power under load. No inflated claims. No guesswork. Just real results.

To use this kit, your ECM must be unlocked via the HP Tuners GM E42 ECM Upgrade Service. This mail-in service is required to make your factory ECM tune-ready.

About the Required ECM Unlock:

The E42 ECM Upgrade Service is the first step in tuning your 2024–2026 Silverado or Sierra HD. Once your order is placed, you'll receive full shipping instructions to send your original ECM to HP Tuners. After unlock, it’s returned fully licensed and ready for RTD-4 use.

Only the original ECM is accepted — no spares allowed.
Requires 8 HP Tuners credits and VCM Suite (Beta).
Return shipping is included.

At Dieselr, we've already tested this unlock on our own fleet of 2024+ L5Ps — so you're not buying blind. You're buying what we run.

✅ What’s Included in the 2024–2026 L5P All-In-One Kit Dieselr:

HP Tuners GM Duramax - E42 Global B Unlock & Upgrade Service
HP Tuners RTD-4
A Single Dieselr custom tune file [Choose from 5 levels with upto +180HP Gain]
8 HP Tuners credits
4” or 5” downpipe-back exhaust or the Cat & DPF Straight race pipe
Dieselr EGR upgrade kit
Dieselr 3.5" downpipe

Important Notes:

No SOTF available — single-level tune only
CAN bus plugs not yet available — Can Bus Systems - NOx & DEF must remain plugged or tied in place. Functionality is unaffected
4–5 day pre-sale processing window

Order your 2024–2026 L5P All-In-One Kit Dieselr now — and get tuned by the team building the future of L5P tuning.

2024-2026 Duramax L5P Bundles

DIESELR GM Duramax L5P All In One Kit (2024-2026)