Speedometer Calibrator | Inline | Chevy/GMC 2500HD/3500HD (17-19)

Rough Country’s Speedometer Calibration Device is an inline, plug-and-play solution designed for Chevy/GMC 2500HD and 3500HD trucks (2017–2019). If you’ve upgraded to larger tires or a lift, this device reprograms your speedometer and updates the ECM so your readings, shift points, and stability control stay accurate.

• Compatibility: Inline speedometer calibrator designed for Chevy/GMC 2500HD/3500HD models from 2017–2019.
• Plug-and-Play Installation: Connects directly to the vehicle’s Diagnostic Link Connector Port with a straightforward setup that can be completed in just a few short hours.
• Accurate Calibration: Reprograms the speedometer to match larger tires and updates the ECM to ensure the in-dash readout, transmission shift points, and electronic stability control reflect real-world performance.
• ECM Update: Goes beyond a display change by synchronizing the ECM with tire-size changes for true vehicle behavior and safety features.
• Reset Function: Includes a way to revert to stock speedometer settings for servicing, maintenance, or tire-size changes.
• Warranty: Backed by a 1-year warranty for reliable, long-term use.

This device addresses a common pain point for lifted or larger-tire GM trucks: a speedometer that no longer matches actual speed, which can affect speed reporting, shift timing, and stability systems. By calibrating the speedometer and updating the ECM, you’ll experience a truthful speed reading, more accurate shift points, and preserved electronic stability control. The reset feature adds flexibility for service or tire changes, while the plug-and-play design makes installation approachable for DIY enthusiasts. All of this comes with a reassuring 1-year warranty.