OBD-II fault codes

What a fault code from the check-engine light means, what usually causes it and how urgent it is. Every generic OBD-II code, the same on every make.

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Code families

Powertrain (P0) 3,703 codes

Powertrain (P2) 3,491 codes

Body (B0) 192 codes

Chassis (C0) 491 codes

Network (U0) 1,054 codes

Network (U3) 174 codes

Code titles and texts come from the open OBDex database, checked against the dtc-database project and a professional mechanic’s workshop list.