Autel MS300 OBD2 Scanner Code Reader User Manual

1. Introduction

The Autel MaxiScan MS300 is a compact and easy-to-use OBD2 scanner designed for car DIYers and beginners. It allows you to quickly read and clear Diagnostic Trouble Codes (DTCs), turn off the Check Engine Light, and check emission monitor status. This tool is an essential addition to any vehicle owner's toolkit, providing immediate insights into potential vehicle issues without the need for professional assistance.

Key features include:

• Reads and clears generic and manufacturer-specific DTCs.
• Turns off the Check Engine Light (MIL).
• Retrieves I/M Readiness status to help pass annual smog checks.
• Displays DTC definitions on screen.
• Powered directly by the vehicle via the 16-PIN OBD2 cable, requiring no batteries.

2. Setup

Setting up your Autel MS300 is straightforward. Follow these steps to begin diagnostics:

1. Ensure the vehicle's engine is turned OFF.
2. Locate the vehicle's 16-pin Data Link Connector (DLC). This is typically located under the dashboard on the driver's side.
3. Firmly plug the Autel MS300's OBD2 connector into the vehicle's DLC.
4. Turn the vehicle's ignition key to the 'ON' position (do NOT start the engine). The scanner will power on automatically.

Figure 2.1: The Autel MS300 scanner with its OBD2 connector, demonstrating its compact size and ease of use. The device features two buttons for navigation and a clear display screen.

2.1 Troubleshooting: Screen Locked in "Linking"

If the screen gets locked in "Linking" mode, ensure you follow the correct order of operation:

1. Turn engine OFF.
2. Plug in the scanner.
3. Turn ignition ON (do not start the engine).

3. Operating Instructions

The Autel MS300 features a simple two-button interface: 'ENTER' and 'SCROLL'.

• ENTER Button: Confirms a selection or action from a menu list.
• SCROLL Button: Scrolls through menu items or cancels an operation.

Figure 3.1: The simple menu display of the Autel MS300, illustrating the intuitive interface for effective operation.

3.1 Reading and Clearing Codes

To read Diagnostic Trouble Codes (DTCs) and clear the Check Engine Light:

1. With the scanner connected and ignition ON, the main menu will appear.
2. Use the 'SCROLL' button to navigate to '1. DTC' and press 'ENTER' to view current codes. If no codes are present, it will display 'NO CODES'.
3. To clear codes, navigate to '2. ERASE' and press 'ENTER'. Confirm your choice when prompted. This will turn off the Check Engine Light.

Figure 3.2: The Autel MS300 indicating successful code erasure, which turns off the check engine light.

3.2 Checking I/M Readiness Status

The I/M Readiness function allows you to check if your vehicle's emission-related systems are operating correctly and are ready for an annual smog check. This helps avoid failed inspections.

1. From the main menu, navigate to '3. I/M' and press 'ENTER'.
2. The scanner will display the status of various monitors (e.g., Misfire, Fuel System, Catalyst, O2 Sensors, EVAP). 'READY' indicates the system has completed its diagnostic cycle, while 'NOT RDY' means it has not.

3.3 Viewing VIN (Vehicle Identification Number)

To retrieve the vehicle's VIN:

1. From the main menu, navigate to '4. VIN' and press 'ENTER'.
2. The scanner will display the vehicle's identification number.

4. Maintenance

The Autel MS300 is designed for durability and ease of use. To ensure its longevity:

• Keep the device clean and free from dust and debris. Use a soft, dry cloth for cleaning.
• Store the scanner in a cool, dry place when not in use. Its compact size allows it to fit easily in a glove compartment or tool bag.
• Avoid exposing the device to extreme temperatures or direct sunlight for prolonged periods.
• Handle the OBD2 cable and connector with care to prevent damage.

Figure 4.1: The Autel MS300 is small and easy to carry, requiring no batteries as it is powered directly by the vehicle's OBD2 socket.

5. Troubleshooting

Most issues with the Autel MS300 can be resolved by ensuring correct connection and operation. If you encounter problems:

• No Power/Display: Ensure the OBD2 connector is firmly plugged into the vehicle's DLC and the ignition is in the 'ON' position. The device draws power directly from the vehicle.
• Linking Error: Refer to the 'Setup' section (2.1 Troubleshooting) for the correct connection sequence.
• Incorrect Code Readings: Ensure the vehicle is OBDII-compliant (generally 1996 and newer for US market, 2006 for EU, 2009 for Asian). Verify the connection is secure.
• Check Engine Light Returns: Clearing codes only turns off the light temporarily. If the underlying issue is not resolved, the light will reappear. Diagnose and repair the root cause of the DTC.

6. Specifications

• Brand: Autel
• Model: MS300
• Product Dimensions: 2.9"L x 0.83"W x 4.4"H
• Item Weight: 7.7 ounces
• Display Resolution: 128x64
• Operating System: Android 4.4 (Note: This refers to the internal system, not user-facing OS)
• Voltage: 12 Volts (powered by vehicle)
• Supported Protocols: KWP2000, ISO2000, ISO9141, J1850 VPW, J1850 PWM, CAN
• Connectivity: Wired, 16 PIN OBD2 cable

7. Warranty & Support

The Autel MaxiScan MS300 comes with a 12-month warranty and free lifetime technical support. For any technical assistance or inquiries, please contact Autel customer support.

You can also refer to the official User Manual (PDF) for more detailed information.

For additional product information and support resources, please visit the Autel Store.