Smart-car diagnostic, built around the way these cars actually break.

Tell us about your car and what it's doing — get ranked causes, next steps, and parts.

Got a fix that worked? Submit it ↗ so the next owner with the same symptom finds it.

Model codes450 1st-gen Fortwo ’98–07451 2nd-gen Fortwo ’07–15452 Roadster ’03–06453 3rd-gen Fortwo + 2nd-gen Forfour ’16+454 1st-gen Forfour ’04–06· body prefix: C coupé · A cabrio · W forfour → e.g. A453 = 2017 cabrio
Contribute to SmartDiag’s knowledge base

Submit a Smart-car issue and fix you’ve confirmed on your own car so SmartDiag can learn from it. A maintainer reviews each submission before it lands in retrieval.

BetaSubmit a fix
Browse manuals on smartcarmanuals.com
Multi-Gen ↗451 ↗452 Roadster ↗453 ↗More resources ↗

Step 1 — Vehicle context

Step 2 — What's happening?

Try:
Add photos (optional) — warning lights, leaks, parts. Up to 3.
JPEG / PNG / HEIC, up to 5 MB each. Photos are sent with the diagnosis — they're not stored.

Step 3 — Run diagnosis

Find Smart specialists near you
Use your location and we'll surface curated shops in your state.
Or browse the full directory:
USA + Canada Smart Mechanics ↗UK / Europe / Global ↗