Autel MS300 OBD2 Code Reader - Compact OBD-II Scanner, Clears Check Engine Light, Emission Readiness

The Autel MS300 is a compact plug-and-play OBD2 code reader that reads and erases diagnostic trouble codes, resets the check engine light, and shows emission readiness status.

If you own a car or light truck built to OBD-II standards, the Autel MS300 gives you fast access to on-board diagnostics without complicated setup. It connects directly to the vehicle’s 16-pin diagnostic port, draws power from the car, and displays stored and pending Diagnostic Trouble Codes (DTCs) with on-screen definitions. This tool is aimed at DIYers, every-day drivers who want to avoid unnecessary repair costs, and technicians who need a reliable, entry-level scanner for quick checks.

How quickly can the MS300 identify vehicle fault codes?

The MS300 retrieves generic and manufacturer-specific DTCs in seconds once plugged into the OBD-II port. It displays code numbers and basic definitions on the screen so you can determine the likely subsystem at fault before proceeding.

• Plug-and-play operation with no batteries required—powered by the vehicle.
• Instant readout of stored and pending codes.
• On-device DTC definitions for quick interpretation.

Can this device turn off the check engine light after a repair?

Yes—the MS300 can clear stored fault codes and reset the Malfunction Indicator Light (MIL) after faults are addressed. Clearing codes temporarily silences the light, but be sure the underlying issue is fixed to prevent recurrence.

• Clear codes function removes stored DTCs and resets the check engine light.
• Useful for confirming whether a repair fixed the problem.
• Simple menu-driven process so beginners can operate it confidently.

Will the MS300 help me prepare my car for an emissions test?

The scanner reads I/M Readiness monitor status so you can see whether systems required for emissions testing—like misfire detection, O2 sensors, catalytic converter and EVAP—are reporting ready. Monitoring these statuses helps avoid failed tests due to incomplete readiness conditions.

• Reports emission monitor readiness for key systems.
• Shows which monitors are not ready so you can address driving or repair needs.
• Supports pre-test checks to reduce the chance of a failed smog inspection.

Which vehicles are supported and what protocols does it use?

The MS300 supports nearly all OBD-II compliant passenger cars and light trucks, covering the major OBD-II communication standards. Compatibility depends on the vehicle meeting OBD-II requirements for its market and year.

• Supports CAN, ISO 9141, ISO 14230 (KWP2000), SAE J1850 VPW and PWM protocols.
• Works with most OBD-II vehicles: typically post-1996 (US), post-2006 (EU), post-2009 (Asia).
• Includes a CD with code definitions and shows many definitions on-screen.

Who is this for? The Autel MS300 is designed for people who want a straightforward, affordable OBD2 reader: DIY enthusiasts, drivers who want to diagnose and clear simple faults themselves, and professional technicians needing a compact tool for quick checks. It’s ideal as a permanent item in a home garage or glovebox when you want rapid code reading, emission readiness checks, and the ability to reset the check engine light without a complicated interface.