Diagnose Your Check Engine Light

Quick Start Guide

1. Turn the key to Accessory (ACC)
   This is usually the 2nd click (just before cranking). If your reader shows no power or “ERROR,” try starting the vehicle fully, then return to ACC.
2. Plug in the OBDII reader
   Connect the reader to the vehicle’s OBDII port (typically under the steering column; sometimes behind a small fuse-panel near the parking brake). If needed, search YouTube for your “year make model obdii port.”
3. Wait for the reader to initialize
   Most readers briefly show “READ” and beep. You’ll then see one or more stored codes, or “ERROR.” If “ERROR,” recheck step 1 and key position.
4. Write down the codes
   Example: P0420, P0301, etc. You can enter these exactly as shown.
5. Search your code on EZOBD2.com
   Enter your code above to get:

   • What it means: Easy description (e.g., P0420 = reduced catalytic converter efficiency, Bank 1).
   • How it works: Short overview of the system and sensors involved.
   • Common issues & symptoms: Likely causes (converter, exhaust leaks, O2 sensors) and what you might notice.
   • Diagnostics & repairs: Tests to try, tools you may need, repair suggestions, and typical costs.
   • Extra tips: Warranty pointers and preventative maintenance.