Free OBD-II Check Engine Code Cheat Sheet
Download the printable quick-reference guide containing the top 50 most common trouble codes, severity indicators, and mechanic-grade fixes.
Download Free PDF Reference
Get the printable check engine code quick-reference guide immediately. Fits in your glovebox or garage.
What's Inside the Guide
This compact reference sheet is designed to print and keep in your vehicle's glovebox or garage. It structures complex diagnostic information into five readable columns:
- DTC Code: The standard 5-character fault code (P0420, P0171, etc.).
- Meaning: Concise description of the failure component.
- Severity Level: Colored badges indicating if the fault is Low, Moderate, or Severe.
- Safe to Drive?: Clear guidance on whether the vehicle can be driven or requires an immediate tow.
- Causes & Fixes: The top mechanical triggers and most likely repair pathways.
Includes critical codes like P0420 (Catalyst), P0171 (Lean Condition), P0300 (Misfire), P0455 (EVAP Leak), P0128 (Thermostat), and 45 other high-frequency vehicle issues.