**************************************************************************************** * ATTENTION: o3DIAG is still in development; some features may not yet work perfectly. * * Latest version: Beta 2.5 | see: /Downloads * ****************************************************************************************
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).
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 (at Beta 1.5).
– 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.
o3DIAG is open source and licensed under MIT-LICENSE.
You can get the code on GitHub see: https://github.com/openw3rk-DEVELOP/o3DIAG
Begin
• Install o3DIAG or compile it from source
• Start o3DIAG
• Press "Info & Warnings"
• READ the Info, Warn and Disclaimer
Connect To Vehicle
• Connect ELM327 adapter to PC and vehicle
• Turn vehicle ignition ON (DONT START)
• Select the right COM-Port for ELM327 adapter
• Adjust the baudrate
• Press "Connect"
Initialize Adapter
• Press "init Adapter"
→ Now you should get data about the adapter,
contains for example ELM327 v1.5.
Read DTCs (Mode "03")
• Press "Read Engine DTC"
→ Now you should get the DTC description.
Clear DTCs (Mode "04")
• Press "Clear DTCs"
→ Now you get this warn: "Really clear stored trouble codes? (OBD-II Mode 04)".
Press "Yes" for clear DTCs or "No" for do nothing.
Other Functions (Version Beta 2.5 or earlier)
• RPM
→ Get the Engine-RPM
• Speed
→ Get the general speed of vehicle (SECOND PERSON USE ONLY!)
• TEMP
→ Get the Coolant temperature
• Load
→ Get the Engine-Load