Fix My Truck
Got a fault code or a truck problem? Follow these four steps to diagnose and fix your diesel truck — without guessing, without wasting money on parts you don't need.
Four Steps to Fix Your Truck
Enter your fault code
Start with your SPN/FMI code from a J1939 scan tool, or your OBD-II P-code from a pickup scan tool. If you don't have a code, describe your symptoms.
Follow the steps
The AI Diesel Tech diagnostic engine guides you through a structured test sequence — cheapest tests first, most likely causes first. No guessing.
Fix the issue
Once the root cause is confirmed, you get a repair plan with the specific parts needed, repair steps, and torque specs where applicable.
Save money
Structured diagnostics eliminate parts cannon repairs. Know exactly what's wrong before you order anything. Most users save $200–$800 per repair event.
What You Need to Get Started
- A fault code from a scan tool (SPN/FMI for commercial trucks, P-code for diesel pickups) — or a description of your symptoms
- Basic information about your truck: year, make, model, and engine
- A digital multimeter for electrical tests (most tests require one)
- Access to the truck for live data testing
Supported Trucks & Engines
Commercial Trucks
Freightliner, Kenworth, Peterbilt, Volvo, Mack, International, Western Star
Commercial Engines
Detroit DD13/DD15/DD16, PACCAR MX-11/MX-13, Cummins ISX15/X15, Volvo D13, Mack MP8
Diesel Pickups
Ford Powerstroke 6.7L, GM Duramax L5P/LML, RAM Cummins 6.7L
Fault Code Protocols
J1939 (SPN/FMI), OBD-II (P-codes), OEM-specific codes
Ready to fix your truck?
Start a guided diagnosis now — no shop visit required.