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OBD-II Diagnostic Helper

Enter any check engine light code and get the technical definition, common causes, and diagnostic steps — instantly.

P, B, C & U codes supportedCommon causes & diagnosisConnect with local Fix shops

Enter OBD-II Code

One letter (P, B, C, or U) followed by four digits

Vehicle (optional — improves accuracy)

Enter the Code

Type in the DTC from your OBD-II scanner or code reader. P, B, C, and U codes are all supported.

Get the Breakdown

Instantly see the technical definition, severity level, common causes, and step-by-step diagnostic guidance.

Find a Shop

We surface local Fix listings that offer OBD scanning and diagnostics so you can get it sorted fast.

Try an example code

P

Powertrain

Engine, transmission, fuel system

B

Body

Airbags, lighting, climate

C

Chassis

ABS, traction, steering

U

Network

Module-to-module communication