GM E41 ECM Services (L5P) - Upgrade Only

Get your L5P Duramax ready to tune. The E41 engine computer in 2017-2023 Chevrolet Silverado and GMC Sierra 2500/3500 trucks with the 6.6L Duramax has to be upgraded before it can be tuned. With this send-in service, HP Tuners upgrades your ECM so you can calibrate, data log and flash through the OBDII port.

2018-2023 owners, read this first: your truck can now be upgraded straight through the OBDII port with an MPVI3 or MPVI4 and 6 Universal Credits. No send-in is needed. This service is for 2017 trucks, and for owners who would rather have HP Tuners do the upgrade. 2017 owners can also do it at home with the GM E41 ECM Upgrade Kit.

This is a send-in service. Your ECM has to come out of the truck and ship to HP Tuners, so the truck will be down while it's away. Please read this whole page before ordering.

Will it work on my truck?

• 2017-2023 Chevrolet Silverado 2500 HD / 3500 HD 6.6L Duramax (L5P)
• 2017-2023 GMC Sierra 2500 HD / 3500 HD 6.6L Duramax (L5P)
• 2024 and newer L5P trucks are Global B and are not covered by this service.

What else you'll need (sold separately)

• 6 Universal Credits to license the E41 ECM.
• An HP Tuners MPVI2, MPVI2+, MPVI3 or MPVI4.
• The latest VCM Suite BETA software (free from HP Tuners).

How it works

1. Confirm your truck is covered and place your order.
2. Our team emails you the order number and the HP Tuners shipping form.
3. Remove the ECM, pack it carefully with the completed form inside, and write the order number on the outside of the box.
4. Ship it to HP Tuners with any carrier. Shipping to HP Tuners is the customer's responsibility; the shipping charged at checkout covers the return trip.
5. HP Tuners upgrades the ECM and ships it back. Allow up to 10 business days once it arrives, plus shipping.
6. Reinstall it, license it with 6 Universal Credits and start tuning.

Ship to:
HP Tuners, LLC
ATT: GM E41 ECM Service (L5P)
[Your order number]
711 Dartmouth Lane
Buffalo Grove, IL 60089

Wait for our email before you ship. Please don't send your ECM until you have the order number and shipping form.

Before you ship: important

• ECMs with broken locking tabs or connectors will not be accepted.
• No immobilizer relearn, crank relearn or "Replace ECM" procedure is needed as long as the ECM goes back into the same truck. A spare ECM will need those steps.
• Once upgraded, no other tuning or calibration tools can be used on the ECM, including dealer reflash tools. Scan tools and dealer diagnostics keep working, and you can return to stock any time with VCM Suite.