How to Fix Check Engine Light
Learn how to fix check engine light with our detailed step-by-step guide. Follow our easy instructions to get it done right.
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0 of 6 steps completedStep-by-Step Instructions
1 Step 1: Scan for Trouble Codes
Step 1: Scan for Trouble Codes
Use OBD2 scanner to read codes causing check engine light, write down code numbers.
OBD2 Code Reader
Scanner for reading and clearing engine codes
2 Step 2: Research Code Meanings
Step 2: Research Code Meanings
Look up code definitions online or in manual to understand what system or component failed.
Code Reference Book
Guide to OBD2 diagnostic trouble codes
3 Step 3: Diagnose Root Cause
Step 3: Diagnose Root Cause
Don't just replace code-indicated part - test related components to find actual problem.
Digital Multimeter
Tester for checking sensors and electrical circuits
4 Step 4: Repair or Replace Failed Component
Step 4: Repair or Replace Failed Component
Fix identified problem: replace sensor, repair leak, clean mass airflow sensor, etc.
5 Step 5: Clear Codes and Test Drive
Step 5: Clear Codes and Test Drive
Use scanner to clear codes, drive vehicle through full drive cycle to verify fix.
6 Step 6: Re-scan if Light Returns
Step 6: Re-scan if Light Returns
If light comes back, re-scan for codes - may indicate additional problems or incorrect diagnosis.
Live Data Scanner
Advanced scanner for monitoring sensor values in real-time