Search our comprehensive database of automotive diagnostic trouble codes (DTCs). Find OBD-II fault code definitions, possible causes, and diagnostic information across all major vehicle makes. Built by professional automotive technicians, for professional automotive technicians.
Enter a fault code (e.g. P0300) or keyword (e.g. "misfire") to search.
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Diagnostic Trouble Codes are organised into categories by their prefix. P-codes relate to the powertrain (engine & transmission), B-codes to body systems, C-codes to chassis, and U-codes to network communication.
Find manufacturer-specific fault codes for your vehicle. Each make includes both generic OBD-II codes and proprietary codes unique to that manufacturer.
When your vehicle's check engine light illuminates, the onboard computer has stored one or more Diagnostic Trouble Codes (DTCs). These codes follow a standardised format defined by the OBD-II (On-Board Diagnostics) system, making it possible for automotive technicians to quickly identify the area of concern.
Each fault code begins with a letter indicating the system involved: P for Powertrain (engine and transmission), B for Body (airbags, seatbelts, climate), C for Chassis (ABS, steering, suspension), and U for Network Communication (CAN bus, module communication). The first digit after the letter indicates whether the code is a generic OBD-II standard code (0) or a manufacturer-specific code (1). The remaining digits narrow down the specific fault.
Generic codes (like P0xxx and P2xxx) are standardised across all vehicle makes and follow SAE (Society of Automotive Engineers) definitions. Manufacturer-specific codes (like P1xxx and P3xxx) are defined by individual automakers and may vary in meaning between brands. Our database includes both types, covering 46 vehicle makes with over 8,602 individual code entries.
The Automotive Technician (TaT) provides professional automotive technicians with a complete diagnostic toolkit. Beyond this fault code library, TaT members have access to known good scan and scope data, repair solutions from real-world fixes, AI-powered diagnostic assistance, and a community of experienced technicians. Our data is compiled and verified by working professionals in the automotive repair industry.
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