Autel MS300 OBD2 Code Reader - Compact OBD-II Scanner, Clears Check Engine Light & Reports Emissions 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 reports emissions readiness.

The MS300 is a handheld car scanner designed for drivers who want a simple, reliable way to diagnose basic engine and emissions issues without expensive shop visits. It plugs into any standard 16-pin OBD2 port, powers from the vehicle, and displays diagnostic trouble codes (including many manufacturer-specific DTCs) with in-device definitions and included lookup software. Lightweight and rugged, the MS300 is a practical tool to keep in a glovebox for quick checks and for confirming repairs before heading to a repair shop or smog test.

How does the Autel MS300 help me identify engine problems?

The MS300 reads stored, pending, and permanent DTCs and displays code definitions on-screen so you can understand what triggered the check engine light. After reading codes you can research the meaning with the included software or online references to decide next steps.

• Retrieves generic and many manufacturer-specific DTCs.
• Displays code definitions directly on the device.
• Includes CD-based lookup software for deeper descriptions.
• Quick readout in seconds after plugging into the OBD2 port.

Can the MS300 turn off a check engine light?

Yes — once you confirm the underlying issue has been addressed, the MS300 can clear stored codes and turn off the malfunction indicator lamp (MIL). Clearing codes can also verify whether a fault was temporary or persistent after a repair or maintenance step.

• Clears engine fault codes and resets the MIL.
• Useful for confirming repairs or dismissing transient faults.
• Does not replace professional repairs when faults require parts or labor.
• Simple, menu-driven erase function for quick use.

Will this tool help my car pass an emissions (smog) inspection?

The MS300 reports I/M Readiness monitors so you can check whether emissions systems have completed their self-tests. That helps you spot incomplete monitors or ongoing issues that could cause a smog test failure before you pay for the inspection.

• Displays readiness status for monitors like O2 sensors, catalyst, EVAP, misfire, and fuel system.
• Shows whether monitors are “ready” or still pending.
• Helps avoid surprise smog test failures with a pre-check.
• Compatible with vehicles that support standard OBD2 readiness reporting.

What vehicles and protocols does the MS300 support?

The MS300 supports the full set of standard OBD2 protocols used worldwide and works on the vast majority of OBD-II compliant cars and light trucks. Typical compatibility covers U.S. vehicles from 1996 onward and many international models from their respective OBD2 adoption years.

• Supports all common OBD-II protocols including CAN, ISO, KWP2000 and J1850 variants.
• Works on about 99% of OBD-II compliant vehicles (passenger cars and light trucks).
• Powered by the vehicle — no batteries required.
• Includes a 12-month warranty and free lifetime technical support from Autel.

Who is this for? The Autel MS300 is built for car owners, DIYers, and first-time vehicle technicians who want an affordable, no-frills diagnostic reader to identify and clear engine codes, verify emissions readiness, and avoid unnecessary diagnostic fees. It’s ideal for anyone who wants a fast way to check why a check engine light is on, confirm a repair fixed the underlying issue, or pre-check a vehicle before a smog test. For advanced, bidirectional or live-data diagnostics, professional-grade scanners are recommended, but the MS300 covers the core needs for routine troubleshooting and emissions verification.