Autel MS309 Review: The Cheap but Reliable Code Reader

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Autel MS309 OBD2 scanner is one of the newer releases of Autel, a company dedicated to delivering innovative diagnostic products after years of research and development. 

This Autel MS309 review and buying guide will give you a birds' eye view of what you get from this affordable yet functional OBD2 scan tool.

Technical Features of the Autel MaxiScan MS309 Scanner


Autel MS309


Backlit, 128x64 pixel display

Operating Temp

0 to 60 ℃ (32 to 140 ℉)

Storage Temp

-20 to 70 ℃ (-4 to 158 ℉)


8 to 18 V provided via the vehicle battery


4.34” x 2.74” x 0.80” (LxWxH)


Autel MS309 fault code reader
Autel MS309 fault code reader


  • Retrieves generic and manufacturer-specific trouble codes
  • Lightweight and compact design
  • Built-in DTC library
  • Compatible with all OBD2 protocols
  • Affordable


  • Not best for intermediate and professional mechanics
  • Thin wires on the cable

Features and Benefits


Autel MS309 OBD II code reader is a state-of-the-art automotive tool that provides professional mechanics with everything they need to diagnose and service modern vehicles. 

It gives an accurate reading and clearing your codes to turn off the check engine light, detects pending codes, and P0, P2, P3, and U0 trouble codes.


Cars compatible with Autel MS309

The OBD II scan tool has worked with domestic, Asian, and European vehicles from 1996 on. It also supports all five OBDII protocols: KWP2000, ISO2000, ISO9141, J1850 VPW, J1850 PWM, and CAN.


Autel MS309 code reader won't smother you with so many navigation buttons. Instead, they made everything simple by cutting navigation buttons to two. However, it still gives you the same information as other scanners.

Displays freeze frame data

Even though the MS309 is most useful when diagnosing continuous system faults like engine misfires and fuel control concerns, it can also be used for data retrieval, allowing you to display and view freeze frame data directly on the code reader.

Emissions-related faults not only set a code but also record a snapshot of the vehicle's operating parameters to help identify the issue. Autel MS309 code reader gives freeze frame data that includes essential engine parameters such as engine RPM, vehicle speed, mass airflow, or closed-loop status.

I/M Readiness Tests

Information displayed on an OBD2 code reader

Autel MaxiScan MS309 code reader places a particular focus on emission-related components, so you know the I/M readiness status of your car.

The monitor shows readiness status with a series of monitors, including continuous monitors like misfire and fuel system. It also indicates non-continuous monitors such as exhaust gas recirculation (EGR) system, oxygen sensors, catalysts, evap emissions control equipment.

Value for money

Autel MaxiScan MS309 code reader is very affordable, but it does more than just reading and clearing OBD II codes. 

It also allows you to view freeze frame data and performs O2 sensors tests, component tests, and onboard monitor tests. Aside from this, you also get an I/M readiness status to get you ready for your state emissions test.


Driver giving an okay sign for OBD codes fixed using the Autel MS309

The MS309 features an OBD II code reader that retrieves the Vehicle Identification Number (VIN), Calibration ID (CID), and Calibration Verification Numbers (CVN). 

This function is handy while taking this small pocket OBD II code reader with you to a used car dealership to make sure the VIN matches.

Autel MS309 FAQ

What is the best OBD2 Scanner for home use?

We recommend basic OBDII code readers to diagnose your car's trouble codes to remove the check engine light for home use. Unless you usually work on a fleet of vehicles, you don't need expensive OBDII scanners.

What does "no codes stored in module" mean?

If you see the light come on your vehicles but register no codes stored in the ECU, there is more likely to be short to power on the circuit. 

Another cause may be a software error from the inferior kind of code reader. It is therefore vital that you review the code readers you want to buy before actually buying them.

We also recommend that you get a deep scan for your car to determine the source of the issue, especially if these are manufacturer-specific errors.


Whether you're a car enthusiast or someone who just needs to know about their vehicle, the Autel MS309 is an affordable yet functional OBD2 scan tool that will help you get all the information necessary for your car.