L5P Transmission (TCM) Tuning Kit for 2017-2025 GMC/Chevy 6.6L Duramax

Our L5P TCM tuning package delivers premium transmission calibrations for 2017–2025 GM Duramax L5P trucks, perfectly optimized to pair with upgraded powertrains. You only need to license your factory TCM and upload our pre-built tune files. It recalibrates shift timing, shift points, torque converter lockup behavior and transmission hydraulic line pressure entirely. This full transmission control module enhancement requires zero replacement physical components.

Key Features & Build Details

• No extra hardware required: Fully compatible with your stock T87A & T93 TCM units. Just complete licensing and flash the provided tune file directly.
• Redesigned shift maps: Factory shift routines are reworked to accommodate heavy diesel hauling and daily driving loads.
• Custom shift point calibration: Upshift and downshift trigger points are raised/lowered past OEM factory limits.
• Smooth, consistent shifting: Shift timing and smoothness are precisely calibrated for steady, predictable gear changes in all driving scenarios.
• Optimized torque converter lockup: Revised lockup logic cuts torque slippage under load while boosting overall fuel efficiency.
• Recalibrated transmission line pressure: Higher adjusted line pressure delivers firmer clutch clamping to handle increased torque output reliably.

Specification

What's Include? ( Denpends on what you choose )

• GM Duramax L5P TCM Tune File — Advanced year-matched calibration file for your existing T87A or T93 TCM
• 4x OBD2 Tuning Credits — Required to flash the tune file via your OBD2 interface
• Vehicle License — Standard licensing for your truck
• OBD 2 Flash Tuning Interface
• Note: An OBD 2 Flash Tuning Interface is required to flash the included tune file. Your existing T87A or T93 TCM will be automatically detected when you connect via OBD2. No hardware replacement needed.

What Changed in 2026

• T87A (2017–2019): As of early 2026, GM T87A TCMs no longer require a hardware upgrade. Your existing T87A can now be licensed and tuned directly — no new module needed.
• T93 (2020–2025): As of March 17th, 2026, users no longer need to upgrade the GM T93 TCM with a send-in service or this upgrade kit. Simply license and tune the controller as normal.

Q: Do I need to buy a new TCM?
A: No. This bundle works with your existing T87A (2017–2019) or T93 (2020–2025) TCM. You only need the tune file and credits to flash your current unit.

Q: What is the difference between T87A and T93?
A: The T87A is used in 2017–2019 L5P trucks (6-speed and 10-speed transmissions). The T93 is the successor for 2020–2025 L5P diesel applications. Both can now be tuned directly without hardware upgrades.

Q: I have a T93 — do I need to purchase an upgrade?
A: No. As of March 17, 2026, you can upgrade your T93 TCM directly via OBD2 for FREE. Simply license and tune as normal with this bundle.

Q: Does this bundle fit gas engine trucks?
A: No. This bundle is for L5P diesel applications only.

Q: I already own the OBD2 interface — how do I use the included credits?
A: Provide your interface serial number at checkout and the 4 credits will be registered to your device.

Q: Is this product refundable?
A: No. This is a final sale, non-refundable product. Confirm your year selection and verify you have the required OBD2 interface before ordering.

Q: What if I need a physical replacement TCM?
A: If your T87A or T93 is damaged or defective, contact us separately. This bundle is for tuning existing, functional TCMs only.

• 2017-2023 Chevrolet Silverado 2500/3500 L5P 6.6L Duramax
  
• 2017-2023 GMC Sierra 2500/3500 6.6L L5P 6.6L Duramax
• Tuner Requirement: Only compatible with MPVI3 or MPVI4 tuner