SOTF Switch

Why Does Your Diesel Truck Need a SOTF Switch?

Reflashing The ECM For Every Tune Change

Without a switch on the fly setup, changing tunes means parking the truck, hooking up the handheld, and waiting through a full ECM reflash every single time. On a working rig that is five to ten minutes of dead time per swap, and in a busy shop those minutes stack up fast across every truck in the bay.

One Tune Does Not Fit Every Load

A single fixed file forces a bad compromise. Run a Race calibration while towing heavy and your exhaust gas temperature climbs, your transmission takes a beating, and the turbo works too hard. Run a Tow tune empty on the highway and you give up the horsepower and economy the engine is built to deliver.

Lost Tune Control On A Deleted Or Tuned Truck

Once a truck is tuned or deleted, the factory tune selector is gone, leaving the driver stuck on one aggressive file with no clean way to dial the power back for street driving, emissions checks, or handing the keys to another driver.

What Can a SOTF Switch Solve?

Instant, Repeatable Level Changes

The 5-position rotary dial delivers discrete, repeatable voltage steps that the tuner reads as specific, pre-written tune files. All the torque and fuel tables for every level are loaded into the ECM up front, which is exactly why the power changes the instant you turn the knob.

A Clean Hardwired Signal Path

The sealed connector taps the charge air cooler intake air temperature circuit, or feeds a direct EZ Lynk and SCT X4 input, so position changes register without a single reflash. Gold-plated contacts hold that signal steady across every detent.

Plug-And-Play Cab Control

A pre-terminated harness routes through the firewall to a cab-mounted knob within reach of the driver seat. You get on-demand control of Stock, Tow, Street, Performance, and Race calibrations without ever leaving the cab.

Shop SOTF Switch by Engine & Fitment Guide

• SOTF Switch for 6.7L Powerstroke - Fits the 6.7L Powerstroke in Ford F250 and F350 (2011-2020), spanning first-generation 2011-2016, second-generation 2017-2019, and 2020 trucks. 5-position dial plugs into the charge air cooler signal for instant Stock to Race level changes.
• SOTF Switch for 6.7L Cummins - Fits the 6.7L Cummins in Dodge Ram 2500 and 3500 (2010-2020), covering the early 6.7 and later generations. Hardwired for EZ Lynk tuning so you switch levels with no reflash.
• SOTF Switch for 6.6L LB7 Duramax - Fits the 6.6L LB7 Duramax in Chevy Silverado 2500HD and GMC Sierra (2001-2004). Sealed connector feeds a clean position signal to SCT X4 and EZ Lynk calibrations.
• SOTF Switch for 6.6L LBZ/LMM Duramax - Fits the 6.6L LBZ and LMM Duramax in Chevy Silverado and GMC Sierra (2006-2010). Rotary knob cycles through Tow, Street, and Performance files on demand.
• SOTF Switch for 6.6L LML Duramax - Fits the 6.6L LML Duramax in Chevy Silverado 2500HD and GMC Sierra (2011-2016). Gold-plated contacts hold a stable signal across every power level.

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The industry standard for high-performance diesel reliability.

Premium Quality & Rigorous Testing

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We aren't just selling parts. We live in this industry. With two decades of hands-on experience providing specialized modification solutions for heavy-duty truck owners, our upgrades have been extensively proven across every driving environment, from daily towing to high-performance tracks.

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What is a SOTF switch?

A SOTF (switch on the fly) switch is a cab-mounted rotary dial that lets you change between pre-loaded custom tunes while the truck is running, without reflashing the ECM.
It taps into the tuner signal circuit, often through the charge air cooler intake air temperature input, so each click of the knob loads a different horsepower level instantly.
You get on-demand control of Stock, Tow, Street, Performance, and Race calibrations right from the driver seat.

What does SOTF stand for, and is it switch on the fly or shift on the fly?

SOTF stands for switch on the fly, and you will hear it called shift on the fly interchangeably in the diesel community.
Both terms mean the same thing on a tuned truck: you change the active tune while driving instead of parking to reprogram.
It has nothing to do with the transfer case 4WD shifter that shares the same name.

How many power levels does the dial have?

Most of our SOTF switches are 5-position rotary knobs, labeled Stock, Tow, Street, Performance, and Race.
Each detent sends a distinct voltage step that the tuner reads as a separate tune file already written to the ECM.
The torque and fuel tables for every level are loaded up front, which is why the change is instant.

Will this SOTF switch work with my SCT X4?

Yes, the switch is built to interface with popular handhelds including the SCT X4, SCT BDX, SCT GTX, and SCT Livewire, plus the EZ Lynk platform.
The dial feeds the tuner a clean position signal so you never reflash between levels.
Confirm your specific device and tune file in the product listing before you order.

Does the SOTF switch need WiFi or a cell signal?

No. The SOTF circuit is hardwired straight to the tuner, so it works with zero wireless connection.
An EZ Lynk setup may use WiFi to load the tunes the first time, but the on-the-fly switching itself is a direct wired signal.
That is exactly why the dial responds the moment you turn it.

Will a SOTF switch fit my 6.7 Powerstroke?

Our Ford SOTF switch fits the 6.7L Powerstroke in 2011 to 2020 F250 and F350 Super Duty.
That single SKU covers the first-generation 2011 to 2016 trucks, the second-generation 2017 to 2019 trucks, and the 2020 model year.
It is built around the Ford charge air cooler signal path for a plug-and-play install.

Will a SOTF switch fit my 6.7 Cummins?

Our Ram SOTF switch fits the 6.7L Cummins in 2010 to 2020 Ram 2500 and 3500.
It is popular with EZ Lynk tuning on these trucks and is hardwired for instant level changes.
The pre-terminated harness matches the Ram charge air cooler circuit for a clean install.

Is there a SOTF switch for the L5P Duramax?

Our Duramax SOTF lineup currently covers the LB7 from 2001 to 2004, the LBZ and LMM from 2006 to 2010, and the LML from 2011 to 2016.
There is no supported switch for the 2017 and newer L5P, because that engine runs a locked ECM that does not accept the SOTF position signal.
If you have an L5P, confirm current availability with our techs before ordering so we do not waste your time.

Can I install the SOTF switch myself?

Yes, most owners install the switch in the driveway in under an hour with basic hand tools.
You route the pre-terminated harness through the firewall, tap the charge air cooler signal, and mount the dial within reach of the driver seat.
Wire colors vary by year, so follow the included guide for your exact truck, and double check that the tuner file is set to SOTF mode.

Are SOTF switches street legal?

Tow and Street tunes on an emissions-intact truck stay a street performance accessory, but the high-output Race and Performance calibrations are intended for competition and closed-course off-road use only.
Removing or altering emissions equipment violates federal and state law on public roads, so verify your local rules before you tune.
Every switch includes free shipping, is backed by a 1-year warranty, and comes with our 45-day return policy, and our techs will confirm fitment for your engine and year before you buy.