E41 ECM Upgrade Kit (2017-2023 L5P GM Duramax 6.6L)

The E41 ECM Upgrade Kit gives you the ability to upgrade 2017–2023 Chevy Silverado and GMC Sierra 6.6L Duramax E41 controllers without removing the ECM from the truck. As an authorized HP Tuners partner, Dieselr offers this kit for shops, professional tuners, and diesel owners who want a clean, repeatable upgrade process with zero risk to factory tabs or connectors.

With this kit, the entire upgrade is performed in-vehicle—no IMMO relearn, no crank relearn, and no “Replace ECM” procedure required. Start to finish, the process takes about 20 minutes using an MPVI2+ (with Pro Feature Set) or MPVI3 device, the included USB cable, and a VCM Suite-compatible computer running the latest BETA version.

Once the E41 ECM is upgraded, the controller becomes fully accessible through VCM Suite. You gain complete scan, data log, read, edit, and write capability, with write times averaging roughly six minutes. For diesel tuning shops and high-volume users, this provides a fast, predictable workflow built around HP Tuners hardware.

E41 ECM Upgrade Kit Benefits

• No ECM removal required
• No IMMO Relearn
• No crank relearn
• No need to perform "Replace ECM" function
• 20-minute upgrade process
• Works with MPVI2+ (Pro Feature Set) or MPVI3
• Compatible with 2017–2023 L5P/L5D Duramax trucks
• Full read/edit/write capability after upgrade
• Clean, repeatable, in-shop workflow used by Dieselr and professional tuners

Alternative Upgrade Option: Direct OBDII Upgrade (2018–2023)

For 2018–2023 L5P/L5D trucks, the ECM can be upgraded directly through the OBDII port using VCM Suite—no kit required.
This method is not supported on 2017 models, which still require either the E41 ECM Upgrade Kit or a send-in service.

The E41 ECM Upgrade Kit remains the most efficient way to prep a 2017–2023 Duramax for controller-level tuning with minimal downtime and direct compatibility with the Dieselr tuning workflow.