Inspection technique avant l'achat d'une voiture d'occasion : peinture, OBD-II et mécanique
Comment vérifier la structure au micromètre (µm), détecter un effacement récent des codes OBD-II et tester le groupe motopropulseur.
| Factory OEM Paint Thickness | 90–160 µm (3.5–6.3 mils) exterior panels |
|---|---|
| Door Jambs & Pillars OEM | 55–95 µm (interior structural zones) |
| Repaint / Body Filler | 180–300 µm (second coat) · >350 µm (putty) |
| OBD-II PID $01 31 | Distance traveled since DTCs cleared (target > 500 km) |
1. Structural Pillars vs Cosmetic Panel Repainting
Always measure the roof first to establish the factory baseline (typically 90–140 µm on Japanese/Korean cars and 110–160 µm on European cars). Cosmetic respraying of a bumper or lower door (180–260 µm) is minor, whereas readings >300 µm on A/B/C pillars, rocker sills, or strut towers indicate structural collision repair.
2. Checking OBD-II Readiness Monitors & Distance Since Code Clear
A dark Check Engine Light on the dashboard is not enough. Connect an OBD-II scanner and read PID $01-01 (Readiness Monitors) and PID $01-31 (Distance traveled since codes cleared). If Catalyst, EVAP, or O2 monitors show 'Incomplete' and distance since clear is < 50 km, fault codes were erased right before your visit.