Diesel trucks have a bad reputation when it comes to throttle response. It begs the question – what if there was a way to get that longed-for feeling of responsiveness in a diesel? JMS has the answer in its PedalMax. The PedalMax operates as a throttle sensitivity booster, which means that it takes the normal throttle input signal from your throttle pedal, and “boosts” it so that the computer reads it as a much more demanding input.
JMS PedalMax throttle sensitivity booster mounts inline between the throttle position sensor and the vehicle harness and is available for all of the Big Three’s diesel trucks, covering Power Stroke, Duramax, and Cummins options. Model years for each manufacturer are as follows: 2011-18 Ford Super Duty, 2008-18 Chevrolet/GMC HD, and 2007-18 Ram HD. JMS also covers multiple other makes and models, including Polaris UTVs, Jeeps, Land Rovers, and Toyotas.
Installing the device is a cinch, and more or less follows the same steps from one manufacturer to the next. You can see how we did it our videos covering Ford, GM, and Ram applications, which you can view here in this article.
Installing starts with undoing the positive battery terminal and plugging the PedalMax to the supplied wiring harness. Next, the PedalMax plugs in between the throttle position sensor and OE wiring harness. Afterwards, the PedalMax should be tied up and secured out of the way using the supplied zip-ties. A 12-volt input pairs with the main harness to supply constant power to the PedalMax, and connects directly to the vehicle battery’s positive terminal or fuse box.
Once you’ve wired it all up, it’s time to test it out. You should see a green light illuminate on the PedalMax, meaning everything is hooked up perfectly. You can now take the truck out for a test drive. Right away, you’ll notice how responsive and quick the pedal works. That’s the magic of PedalMax. You’ll also see that we found some slight gains from dyno testing the PedalMax in a 2016 Ram 2500 and 2017 Chevrolet 2500HD; you can watch the videos to see the exact numbers.
What’s more, if you think the PedalMax throttle sensitivity booster is a bit too aggressive, JMS has you covered. You’ll notice there is a RED desensitizing plug that comes with the device. You can use that to dial back the responsiveness from 100 percent to 60 percent. It works by simply plugging into the four-pin connector on the device.
If you decide you’d like even more control over the PedalMax, you can opt for the control accessory, which uses a dial to adjust between stock to 100-percent sensitivity. It uses the same four-pin connection as the RED desensitizing plug, and can mount on your dashboard using supplied hardware. We recommend placing it in a spot where it won’t accidentally come into contact with your body.