Our free app reads J1939 fault codes, shows live engine data, and translates SPN/FMI codes into plain language with links to our fault-code library. It runs with any ELM327-compatible 9-pin Bluetooth adapter (from $25) — the diagnostic layer every driver should have in the cab.
What the free tier does (and doesn't)
| Free app | Pro tools | |
|---|---|---|
| Read J1939 faults | Yes | Yes |
| Clear codes | Basic | Full, all modules |
| Live data | Engine basics | All parameters, all ECUs |
| SPN/FMI translation + fixes | Yes — links to our library | Built-in guided diagnostics |
| Forced DPF regen | No — hardware-safety decision | Yes |
| Bi-directional controls | No | Yes |
Why no regens in the free app? Commanding a regen through a $25 generic adapter without precondition validation is how trucks get hurt. Regens require proper CV hardware — that's a safety line we won't blur for downloads.
The upgrade path (when you're ready)
- Outgrew code-reading? The $499–$899 tier adds regens and bi-directionals.
- Making money from diagnostics? The MS909CV or a Jaltest kit is the professional step.
- Stuck right now? Remote diagnostics — a technician on your truck by phone, $149.
Frequently Asked Questions
What adapter does the free app need?
Any ELM327-compatible Bluetooth or Wi-Fi adapter with a 9-pin truck cable — we sell a verified one for $39, or use your own. Cheap adapters vary in J1939 reliability; ours are tested against all major platforms.
Is the app really free? What's the catch?
Free tier is free forever — the business model is that some percentage of users eventually need pro tools, and we sell those. No ads, no data selling, no email-bomb drip. You get a welcome email and one follow-up; unsubscribe any time.