How to use an OBD2 scanner

How to use an OBD2 scanner: An OBD2 scanner is a powerful tool for diagnosing vehicle engine and system issues. Follow these steps to effectively retrieve diagnostic trouble codes.

Salman Chaudhary, Founder

How to Use an OBD2 Scanner

An OBD2 scanner is a valuable tool that allows you to diagnose and troubleshoot issues with your vehicle's engine and onboard systems. In this comprehensive guide, we'll walk you through the steps on how to effectively use an OBD2 scanner to retrieve diagnostic information, understand trouble codes, and potentially resolve minor issues on your own.

Understanding the OBD2 System:

Before diving into the steps, it's essential to have a basic understanding of the OBD2 system:

  • OBD2 Port Location: The OBD2 port, where you connect the scanner, is typically located under the dashboard near the driver's seat. Refer to your vehicle's manual or search online for its specific location.

  • Diagnostic Trouble Codes (DTCs): These are alphanumeric codes that the OBD2 system generates to indicate potential issues with your vehicle. Each code corresponds to a specific problem.

  • OBD2 Scanner Types: OBD2 scanners come in various forms, from basic code readers to more advanced diagnostic tools. The steps outlined here apply to most types, but specific scanner models may have unique features or procedures.

Using an OBD2 Scanner:

Step 1: Prepare Your OBD2 Scanner:

  • Ensure that your vehicle's ignition is turned off.

  • Locate your OBD2 scanner and plug it into the OBD2 port beneath your dashboard. The connector is typically triangular in shape and has 16 pins.

Step 2: Turn On the Ignition:

  • Turn the ignition key to the "On" position without starting the engine. This provides power to the OBD2 system, allowing the scanner to communicate with your vehicle's computer.

Step 3: Power Up the Scanner:

  • Depending on your scanner, it may power on automatically or require manual activation. Refer to your scanner's user manual for specific instructions.

  • Some scanners have a separate power button, while others activate when connected to the OBD2 port.

Step 4: Establish Communication:

  • Once your scanner is powered on, it will attempt to establish communication with your vehicle's onboard computer. This process may take a few moments.

  • Follow any on-screen prompts provided by the scanner. It may ask you to select your vehicle's make and model.

Step 5: Retrieve Diagnostic Data:

  • After successful communication, your scanner will present you with options to retrieve diagnostic data. Common functions include "Read Codes," "Erase Codes," "Live Data," and "Freeze Frame Data."

  • Start with "Read Codes" to retrieve diagnostic trouble codes (DTCs). These codes will help identify specific issues with your vehicle.

Step 6: Interpret Diagnostic Trouble Codes (DTCs):

  • Each DTC corresponds to a specific problem. Use your scanner's user manual or search online to decode these codes.

  • Some scanners may provide brief descriptions of the codes, but additional research may be necessary for a full understanding.

Step 7: Addressing Issues:

  • If you identify trouble codes, take note of them. Some codes may require immediate attention, while others may indicate minor issues that can be addressed later.

  • Conduct further research to understand the causes and potential solutions for the identified issues.

Step 8: Erasing Codes (Optional):

  • If you've addressed and resolved the issues causing the trouble codes, you can use your scanner to erase the codes. This will clear the "Check Engine" light on your dashboard.

  • Be sure that the issues have been resolved before erasing codes, as they can serve as a valuable reference for future diagnostics.

Step 9: Review Live Data (Optional):

  • Some OBD2 scanners allow you to view live data, such as sensor readings and engine parameters, in real-time. This can help diagnose intermittent issues or monitor system performance.

Step 10: Power Down and Disconnect:

  • After using the scanner, power it down following the manufacturer's instructions.

  • Disconnect the OBD2 scanner from the port.


An OBD2 scanner is a powerful tool for diagnosing and understanding issues with your vehicle's engine and systems. By following these steps, you can effectively use an OBD2 scanner to retrieve diagnostic trouble codes, interpret them, and potentially address minor issues on your own. Remember that more complex problems may require the expertise of a professional mechanic. Always refer to your vehicle's manual and your scanner's user manual for specific instructions and troubleshooting guidance.

How to use an OBD2 scanner
How to use an OBD2 scanner