

o3DIAG
o3DIAG is a diagnostic application designed to work with OBD-II vehicles through an ELM327 adapter. It provides an easy way to connect, read vehicle data, and interpret diagnostic trouble codes (DTCs).
Cost / License
- Free
- Open Source
Platforms
- Windows
- Debian



o3DIAG
Features
Tags
- o3script
- elm327
- diagnostic-tool
- o3diag
- Python
- Car Diagnostic and On-Board Diagnostics (OBD)
- obd2-reader
- open source
- o3script-language
- openw3rk
- obd2
- openw3rk-invent
o3DIAG News & Activities
Recent activities
o3DIAG information
What is o3DIAG?
o3DIAG is a diagnostic application designed to work with OBD-II vehicles through an ELM327 adapter. It provides an easy way to connect, read vehicle data, and interpret diagnostic trouble codes (DTCs). Main Features
Connection Control
- Select communication port and baud rate.
- Connect or disconnect the adapter with a single click.
- Initialize the adapter automatically with the required AT commands.
Live Data Reading
- Read common engine parameters such as:
- Engine RPM (PID 010C)
- Vehicle Speed (PID 010D)
- Coolant Temperature (PID 0105)
- Engine Load (PID 0104)
- Raw responses are automatically converted into real-world values (e.g., RPM in revolutions per minute, temperature in °C, speed in km/h).
Diagnostic Trouble Codes (DTCs)
- Read stored error codes from the engine control unit.
- Clear fault codes when required.
- Codes are translated into plain-text descriptions for easier understanding.
P-Code Translation
- The program can look up diagnostic codes (P0000–P0999 and beyond) from an integrated script-based list.
- Instead of showing just the raw code, the program displays the human-readable meaning of each fault.
User Interface
- Scrollable log window that shows all communication with the adapter.
- Each entry is timestamped for clarity (Beta 1.5 or later).
- Clear log function, with an automatic program banner shown again for orientation.
- Info/Warning section with program details and disclaimers.
With o3DIAG, users can quickly access essential vehicle information, monitor live sensor data, and interpret engine fault codes in a clear and user-friendly interface. It is a practical tool for basic diagnostics and understanding of OBD-II data.

