How To Correct The Speed Reading For Those Larger Tires You Put On You – Hypertech, Inc.

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How To Correct The Speed Reading For Those Larger Tires You Put On Your Ram 2500


When you installed those larger than stock tires on your Ram 2500, it's likely that your vehicle's computer didn't adjust to provide an accurate speed reading. And don’t forget, an accurate speed reading is required by law. That inaccurate speed reading can be quickly and easily corrected with the Hypertech In-Line Speedometer Calibrator® Module.

Configuration Before Installation

Before installing the In-Line Speedometer Calibrator Module, you will need to configure the module for the new tire size. This is done with the provided software you download from to your PC. That software lets you then configure the module with your new tire size.


Installation Process

Installation of the In-Line Speedometer Calibrator Module only takes about 20 minutes or so. It installs behind the instrument cluster on the dash. The tools required for this installation are a 7mm nut driver or socket, trim removal tools (optional), and a T-20 Torx screwdriver. Please note that the In-Line Speedometer Calibrator Module will NOT work with Ram 2500 models with the 12 inch digital cluster.

Step-by-Step Installation

Use the trim removal tool to pry the bezel off, starting at the top. Lift the rubber mat off the top of the infotainment display and use the proper driver to unscrew the nuts. Gently and firmly pull backwards to remove it from the dash. Then, remove the four plastic pieces that surround the display of gauges. Remove the dust cover that's on top of the steering column, which might be screwed on. Finally, there are the four bolts that hold the speedometer in place. Remove those, and gently pull the speedometer out of the dash. The applicable cables are on the right side. Pull the connector out of the back of the speedometer, and attach all the matching connectors between the In-line Speedometer Calibrator harness, the module, and the Ram 2500's instrument cluster itself. They only go together one way, so be careful not to damage the pins in the connectors. Secure the cables behind the speedometer with the tie that comes with the module. Then, put everything back together in reverse order. Of course, keep the screws and bolts separate so that you don't accidentally put the wrong screw in the wrong location. Detailed instructions are available at

Enhancing Performance with Hypertech Products

Also, you can combine the In-Line Speedometer Calibrator Module with other Hypertech performance products, like the React Throttle Optimizer®, which gives you complete throttle response control at your fingertips.