Diagnose diesel faults faster. Stop throwing parts at trucks.
Truck Commander Pro turns fault codes, symptoms and live data into a test-first diagnostic sequence — what to check first, what reading confirms the failure and what to rule out before replacing parts. Built from 35+ years of hands-on diesel experience.
- Fault-code explanation
- Test sequence
- Repair guidance
- The tools you'll need
Three free fault-code lookups. Pro is $9.99/month. No contract. Cancel anytime. 14-day refund guarantee.
- Built from 35+ years of diesel experience
- Test-first troubleshooting
- Unlimited Pro diagnostics
- Saved truck and job history
- $9.99/month
Type your code. See what it means.
Straight from our verified fault-code data — what the code means, how serious it is, and the first checks. Three free a day.
A second set of experienced eyes — without the two-hour forum search.
Enter the complete fault code, engine information, symptoms and operating conditions. Truck Commander Pro organizes the possibilities into a practical test order so you can prove the failure before selling parts.
Find the first test
Start with the quickest checks that separate a wiring, sensor, fuel, air or aftertreatment problem.
Document the diagnosis
Save the truck, complaint, codes, readings, repairs and final verification in one job history.
Train without guessing
Give less-experienced technicians a structured process while the experienced tech keeps control of the final decision.
No account required for the first three lookups.
Members found the real failure.
Real stories from drivers and diesel technicians who worked the fault instead of guessing — and proved the cause before parts went on.
Start free. Upgrade when it pays for itself.
Free CDL pretest and free guides
Full CDL written practice tests, diesel fault-code pages and owner-operator guides. Free with your email — no card.
Take the free CDL pretestTruck Commander Pro
One membership unlocks Truck Commander, AI diagnostic help, every calculator, the handbooks and the job board.
See everything includedTruck Commander + AI diagnostics
Your garage, fault-code lookups, HOS, IFTA, pre-trip DVIRs and profit math — synced to your account.
Explore Truck CommanderTraining and business education
Cummins ISX, Detroit DD13/DD15 and Aftertreatment Mastermind, plus the Own Your Truck and Trade Up handbooks.
Browse the Training CenterEverything you get for $9.99 a month
No free trial — you're charged when you join. Cancel anytime.
- CDL written test prep — 8 chapters, unlimited retakes
- Training Center — Cummins ISX, Detroit DD13/DD15 and Aftertreatment Mastermind
- Truck Commander Pro AI diagnostics — fault codes, VIN and serial lookups
- Ask a Tech support and the full fault-code knowledge base
- Truck Driver Command Center — garage, HOS, IFTA, pre-trip, load profit
- Own Your Truck handbooks — 21 chapters, LLC, authority, loads
- Trade Up guide — 10 modules and the 50-state licensing directory
- Every Business Center tool and calculator
- Saved diagnostic history and cloud-synced tool results
Three full diesel training courses.
Cummins ISX, Detroit DD13/DD15, and Aftertreatment Mastermind — all grouped under the Diesel Training Center. Module 1 of Aftertreatment Mastermind is a free preview; everything else unlocks with Pro.
From the test seat to your own name on the door.
Three steps, one membership. Start wherever you are.
- 01
Pass the CDL test
Eight chapters of written-test prep with explanations. Passing the test gets you a seat.
Start here - 02
Get your own truck and authority
Buying the right truck, MC/DOT authority, the insurance stack, loads, and your real cost-per-mile.
Start here - 03
Start your own shop
Trade Up: licensing state by state, pricing your labor, and the paperwork behind your own bay.
Start here
The full Truck Commander lineup.
One toolbox for the whole road.
A mobile command center for drivers and owner-operators — diagnostics, calculators, inspections and your truck history, all synced to your account.
My Truck Garage
Specs, photos, mileage and service history for every unit in one place.
AI Diagnostics
Enter a fault code, VIN or serial and get a ranked troubleshooting plan.
HOS Calculator
11-hour, 14-hour, 30-minute break and 34-hour restart planning.
Pre-Trip Inspector
Digital DVIR with photos, notes and a printable PDF report.
Profit Calculator
Revenue, cost and profit per mile plus break-even for your truck.
Fuel & IFTA
Fuel cost per mile and IFTA estimates across your routes.
What this is not.
- Not accredited, and not affiliated with any government agency. Finishing a course here is not a license.
- Not a replacement for OEM service information — torque specs, pinouts and procedures still get confirmed against the OEM data.
- Not a chat box that guesses. When the AI doesn't have verified data for a code, it says so instead of inventing an answer.
- Not for fleets with 5+ trucks and a bookkeeper, and not a lease-purchase shortcut — the handbooks argue against those.
Made by someone who did the work.
Built from shop-floor experience
TruckCommanderPro.com was built by Christopher Sneed, a diesel technician with 35+ years in the shop — not by a software company guessing at what the work looks like.
Who it's for
CDL students, company drivers, owner-operators, diesel and HVAC technicians, and tradespeople opening their own shop.
What it solves
Passing the CDL written test, cutting diagnostic time on a fault code, and running the money side of a one-truck or one-bay business.
Honest about the AI
AI guidance is a starting point, not a verdict. Always confirm procedures, specs and pinouts against OEM service information before you turn a wrench.
More on the founder’s background: Christopher Sneed, 35+ years in diesel.
Truck Commander Blog
Straight-talk articles for the drivers in the seat and the technicians in the bay. No fluff, no corporate voice.
The Men Behind the Miles
Freight doesn't move because of one guy. It moves because a driver and a technician are both doing their job right.
What a Driver Should Check Before Every Trip
A pre-trip from the technician's side of the bay, and the small stuff that turns into a tow bill.
How to Talk to Your Mechanic
What to bring to the shop so the diagnosis takes an hour instead of a day, and the bill reflects it.
Customer Support
Stuck on a login, a charge, a fault code or a gear order? A real person reads every message — no bots, no ticket maze. Most replies land the same business day.
Start today.Build from there.
One membership covers the whole platform. Start with CDL prep, then run the business side when you're ready.
Christopher Scott Sneed
Founder & Creator of Truck Commander
Built in the Shop. Built for the People Who Keep Trucks Moving.
I didn't build Truck Commander from behind a desk. I built it from decades of experience working on diesel engines and solving the problems that put trucks out of service.
I've spent my career primarily as an engine builder, working on some of the biggest names in the diesel industry — Caterpillar, Cummins, Detroit, Mack, Volvo, and International. I've built a lot of engines, torn them down, found the failures, rebuilt them, and put them back to work.
But engines are only part of the job. I've also spent years diagnosing electrical problems, wiring, sensors, fault codes, communication issues, and the complex systems found on modern heavy-duty trucks.
After seeing how much time technicians and drivers can lose trying to figure out a problem, I knew there had to be a better way to put useful information and diagnostic tools at their fingertips.
That's why I built Truck Commander.
My goal isn't to replace experienced technicians. It's to give them another weapon in the toolbox.
For truck drivers, it's about having better information when something goes wrong. For technicians, it's about getting to the problem faster and working smarter. For both, it's about reducing frustration, reducing downtime, and getting the equipment back to work.
Truck Commander is built from real-world experience and powered by technology.
I've spent years turning wrenches, building engines, chasing electrical problems, and figuring out why trucks don't do what they're supposed to do.
Now I'm taking that experience and putting it into a tool designed to give every technician and truck driver an edge.
Built by a diesel technician. Built for the people who keep America moving.