What to Do When Your Truck Goes Into 5 MPH Derate

What to Do When Your Truck Goes Into 5 MPH Derate

One moment you’re cruising down the road—next thing you know, your truck won’t go faster than 5 MPH. This is called a derate, and it’s your truck’s way of saying: “Fix the problem or I’m shutting down.”

If you’ve ever been stuck on the side of the road crawling to a safe spot, you know how costly and frustrating this is. The good news? Most derates are preventable—and fixable—if you have the right tools.


⚠️ What Is a 5 MPH Derate?

A derate is when your truck's engine control module (ECM) limits performance due to a serious fault. A 5 MPH derate is the most severe—it keeps you from driving until you fix the issue.

Common causes:

  • SPN 5246 – Emissions system fault

  • SPN 3719 – DPF soot level too high

  • SPN 4364 – NOx sensor failed

  • Failed or skipped regen cycles

  • EGR or DEF system issues


🧯 Can You Clear It?

Yes—but only after the root problem is resolved. That usually means:

  • Running a forced regen

  • Replacing a failed sensor (NOx, DEF, temp, etc.)

  • Resetting the derate after repair

But here’s the catch: You can’t do it without the right diagnostic tool.


🛠 The Tool That Can Get You Back on the Road

Our Diesel Diagnostic Laptop Scanner Kit gives you full dealer-level access to:

  • Clear 5 MPH derates and limp mode conditions

  • Run and monitor forced regens

  • Read SPN/FMI fault codes

  • Reset EGR, SCR, and DPF systems after repair

  • Test components (NOx, DEF, EGR, Turbo, etc.)

No subscriptions. No waiting. No towing.


💰 Save Time, Save Money

  • Avoid $1,000+ tow bills

  • No more waiting 3–5 days for dealer appointments

  • Fix and reset on your own schedule—even on the side of the road


✅ Why Drivers Choose DieselScanners.com

  • Preloaded laptop + adapter = plug & play

  • Works with Cummins, Detroit, Volvo, Paccar, CAT, MaxxForce, and more

  • 2-year warranty

  • 30-day full refund guarantee (we pay return shipping)

👉 Don’t let a derate stop your income—get your diesel laptop scanner now