Home > News > How to Install an EZ Lynk SOTF Switch on a 2010+ Ram 6.7 Cummins (30-Minute DIY)
How to Install an EZ Lynk SOTF Switch on a 2010+ Ram 6.7 Cummins (30-Minute DIY)
I remember the first time I towed my 14,000-pound fifth wheel through Colorado with a tuned 6.7 Cummins. I had a fuel economy tune loaded for the flat highway miles across Kansas. When I hit the Eisenhower Tunnel approach — a 7% grade at 11,000 feet — I wanted my tow tune. The one with the aggressive EGT management and low-end torque curve that keeps exhaust gas temps under 1,200°F while climbing.
But to switch tunes, I had to pull over. On the shoulder. Truckers flying past at 75 mph. Pull out my phone. Open the EZ Lynk app. Wait for Bluetooth to connect. Wait 45 seconds for the reflash. All while my trailer sat there bleeding speed at the base of a mountain.
That was the day I ordered a SOTF switch.
What Is an EZ Lynk SOTF Switch?
A Shift On The Fly (SOTF) switch is a physical knob that mounts in your cab and lets you toggle between up to 5 custom tunes — instantly. No phone. No app. No pulling over. Twist the knob, and your ECU switches tune slots in under a second.
The TruckTok SOTF switch ($79.99) connects to your EZ Lynk AutoAgent through the CCV (crankcase ventilation) sensor circuit. It sends a resistance signal that tells the AutoAgent which of your 5 loaded tune slots to activate. The CCV sensor continues working normally — the switch just reads the circuit voltage without interrupting it.
Compatibility: 2010-2024 Ram 2500/3500 with 6.7L Cummins + EZ Lynk AutoAgent (all versions)
What’s in the Box
The TruckTok kit includes everything you need except basic hand tools:
- Knurled aluminum knob with 1-5 position decal
- Pre-wired harness with high-temperature rated wire
- 3-pin CCV plug-and-play connector
- 1/8" split loom tubing for clean wire routing
- Mounting hardware
What you’ll need from your toolbox: drill with 3/8" bit, wire stripper, panel removal tool, zip ties, electrical tape, and a coat hanger (for fishing wire through the firewall — trust me on this one).
Step-by-Step Install
Step 1: Pick Your Switch Location
Three good spots. Pick one:
| Location | Pros | Cons |
|---|---|---|
| Dash panel (left of steering wheel) | Looks factory, easy thumb reach | Requires drilling, dash trim removal |
| Center console (next to 4WD selector) | Most natural reach, easy wire route | Visible wire run, need longer harness |
| Overhead console | Hidden from outside view, clean look | Longest wire run, harder to reach while driving |
I mounted mine on the dash panel left of the steering wheel. It sits right where Ram puts factory auxiliary switches. Looks like it came from the factory.
Step 2: Run the Wiring
Run the harness from your switch location down through the dash cavity, along the driver’s side kick panel, and through the firewall grommet above the brake pedal. The grommet has a rubber nipple — snip the tip off, tape the SOTF harness wire to a straightened coat hanger, and push it through. It’ll pop out in the engine bay near the brake booster.
Wrap the wire in the included split loom, then zip-tie it every 6 inches along the firewall toward the driver’s side valve cover. Keep it away from the exhaust manifold and turbo — there’s a factory wire channel along the firewall that works perfectly.
Pro tip: Feed extra wire into the engine bay. You can always pull slack back into the cab, but if you cut it too short, you’re buying a new harness.
Step 3: Connect the 3-Pin CCV Connector
Locate the CCV sensor on top of the driver’s side valve cover. It’s a black plastic sensor with a 3-pin connector pointing toward the firewall.
Unplug the factory connector from the CCV sensor. Plug the TruckTok SOTF harness 3-pin connector in-line: factory connector → SOTF harness → CCV sensor. It’s plug-and-play — no cutting, no soldering, no tapping into factory wiring.
The SOTF switch reads the 5V reference voltage on the CCV circuit without affecting the sensor’s operation. Your CCV system keeps working. The switch just monitors the voltage to determine which tune slot to activate.
Verify orientation: The connector is keyed — it only fits one way. If it doesn’t click in, flip it 180 degrees.
Step 4: Mount the Switch
Drill a 3/8" hole at your chosen location. Insert the switch body from behind the panel, thread the knurled aluminum knob onto the front threads, and hand-tighten. The split loom should be flush against the back of the panel.
Apply the 1-5 decal around the knob. The decal has adhesive backing — clean the surface with alcohol first and it’ll stay put for years.
Step 5: Configure Your Tunes
The switch doesn’t hold tunes — it tells your AutoAgent which tune slot to run. Open the EZ Lynk app on your phone:
- Connect to your AutoAgent via Bluetooth
- Go to Tunes → SOTF Configuration
- Assign a tune to each switch position
Here’s the setup I run on my 2018 Ram 2500:
| Position | Tune | When I Use It |
|---|---|---|
| 1 | Stock / Emissions-On | Daily driving, state inspections, valet |
| 2 | Economy (+30 HP, +2-3 MPG) | Highway cruising, empty bed, long road trips |
| 3 | Heavy Tow (+80 HP, torque-focused) | 10K+ lbs trailer, mountain grades |
| 4 | Street Performance (+120 HP) | Unladen fun, merging, passing |
| 5 | Race (+200 HP) | Dyno day, track only |
Your setup will depend on what tunes your tuner builds. Calibrated Power, GDP, CTT, PPEI, and Hardway Performance all support 5-slot SOTF tuning — just tell them “I need SOTF-compatible tunes” when you order.
Step 6: Test Before You Drive
- Key ON, engine OFF
- Open the EZ Lynk app → verify all 5 slots register
- Rotate through positions 1-5 → app should show “Slot X Active” for each
- Start engine on Position 1
- Let idle 30 seconds, then twist to Position 2 — you should feel the idle note change slightly
- Repeat through all positions at idle
⚠️ Never switch tunes at wide-open throttle. Switch at idle or steady cruise only. Switching under heavy load can cause a momentary fueling interruption that the ECU interprets as a fault.
3 Common Install Mistakes (That I’ve Seen Firsthand)
1. Not zip-tying the engine bay wiring. That wire will find the exhaust manifold. It’s like a heat-seeking missile. Zip-tie every 6 inches along the factory harness channel.
2. Switching tunes at full throttle. The temptation is real — you’re merging, you want more power, you twist the knob. Don’t. Lift off, twist, wait half a second, then get back into it. The ECU needs a moment to transition between fuel maps.
3. Not loading tunes into all 5 slots. Positions 2-5 will do absolutely nothing if there aren’t tunes loaded. Configure SOTF in the EZ Lynk app BEFORE testing the switch. If position 3 does nothing, you don’t have a tune loaded in slot 3.
Does This Void My Warranty?
The switch itself is a passive electronic component — it doesn’t modify emissions equipment. But the tunes it switches between probably do. If your truck is under warranty and you’re running aftermarket tuning, warranty coverage on engine and emissions components is at risk regardless of whether you use a SOTF switch.
For off-road use only. Check your local regulations.
Shop the SOTF Switch
The TruckTok EZ Lynk/CCV SOTF Switch is $79.99 with free shipping. Includes the knurled aluminum knob, 1-5 decal, 3-pin CCV connector, high-temp rated wire, and split loom.
For install support, join the discussion on our TruckTok Forum.
FAQ
Does this work with a deleted truck?
Yes. The SOTF switch works with any tune on your EZ Lynk AutoAgent — emissions-present or deleted.
What tuners support SOTF?
Calibrated Power, GDP, CTT, PPEI, and Hardway Performance all support 5-slot SOTF tuning. Tell your tuner you need switchable slots.
Can I switch tunes while towing?
Yes, at idle or steady cruise. Avoid switching under heavy load or wide-open throttle.
Does this work with EZ Lynk AutoAgent 2.0 and 3.0?
Yes, both versions. The CCV connector is the same.
How long does install take?
30-45 minutes with basic hand tools. No mechanical experience required.