OBD2 Trouble Codes Guide

Complete database of diagnostic trouble codes with meanings, causes, and solutions

Code Categories

  • P - Powertrain
  • B - Body
  • C - Chassis
  • U - Network

Code Structure

P
0
4
2
0

1st: Category

2nd: Code Type (0=Standard, 1=Manufacturer)

3rd: System

4th & 5th: Specific Fault

Common Systems

  • 1,2 - Fuel and Air Metering
  • 3 - Ignition Systems
  • 4 - Auxiliary Emissions
  • 5 - Vehicle Speed/Idle Control
  • 6 - Computer/Output Circuits
  • 7,8,9 - Transmission

Severity Levels

  • Critical - Immediate attention required
  • Medium - Schedule service soon
  • Low - Monitor and maintain

Filters

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Progress

Primary Symptoms

Step 1 of 5

Vehicle Information

Step 2 of 5

Additional Symptoms

Step 3 of 5

When and How

Step 4 of 5

Diagnostic Results

Final Step

DIY Checks

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Common Fixes

Solutions for frequently encountered issues

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