How to use Autel MaxiScan MS309 OBD2 Code Scanner

Autel MaxiScan MS309 OBD2 code scanner is a must-have tool for rapid vehicle health with the ability to view freeze frame data, check I / M readiness (emissions) and monitor status, etc.

This article will guide you on how to use this MS309 OBD2 code scanner.

Connect the OBD II cable to the code reader.

Find DLC on the vehicle and plug OBDII cable into the vehicle’s DTC.


Click the “SCROLL” button, then the code reader allows you to make the following adjustments and settings:

Language: Select desired language.
Unit of measure: Set the unit of measure to English or Metric.
Contrast adjustment: Adjust the contrast of the LCD display.
Exit: Return to the previous menu


Press the “ENTER/EXIT” button to enter Diagnostic Menu.



After the system status is displayed (MIL status, DTC counts, Monitor status), wait a few seconds or press any key for Diagnostic Menu to come up.


Use the “SCROLL” button to select Read Codes from Diagnostic Menu and press the “ENTER/EXIT” button to read the codes.


A message similar to the following will be displayed:


If you decide to erase the DTCs, use the “SCROLL button” to select Erase Codes from Diagnostics Menu and press the “ENTER/EXIT” button.



If you want to query View Freeze Frame, I / M Readiness and Vehicle Info, do the same, use the “SCROLL” button to select and press the “ENTER / EXIT” button to continue.



If you want to know more about the operation of MS309, please refer to the Autel Maxiscan MS309 user manual:


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