Autel MaxiScan MS300 OBD II Scan Tool User Manual

On-Board-Diagnostics (OBD) II

The first generation of On-Board Diagnostic (called OBD I), was developed by the California Air Resources Board (ARB) and implemented in 1988 to monitor some of the emission control components on vehicles. As technology evolved and the desire to improve the OBD I system increased, a new generation of On-Board Diagnostics system was developed. This second generation of On-Board Diagnostic regulations is called "OBD II".

The OBD II system is designed to monitor emission control systems and key engine components by performing either continuous or periodic tests of specific components and vehicle conditions. When a problem is detected, the OBD II system turns on a warning lamp (MIL) on the vehicle instrument panel to alert the driver typically by the phrase of "Check Engine" or "Service Engine Soon". The system will also store important information about the detected malfunction so that a technician can accurately find and fix the problem. Here below follow three pieces of such valuable information:

• Whether the Malfunction Indicator Light (MIL) is commanded 'on' or 'off';
• Which, if any, Diagnostic Trouble Codes (DTCs) are stored;
• Readiness Monitor status.

Diagnostic Trouble Codes (DTCs)

OBD II Diagnostic Trouble Codes are codes that are stored by the on-board computer diagnostic system in response to a problem found in the vehicle. These codes identify a particular problem area and are intended to provide you with a guide as to where a fault might be occurring within a vehicle. OBD II Diagnostic Trouble Codes consist of a five-digit alphanumeric code. The first character, a letter, identifies the control system which sets the code. The other four characters, all numbers, provide additional information on where the DTC originated and the operating conditions that caused it to set. Here below is an example to illustrate the structure of the digits:

DTC Example Diagram: Shows a breakdown of a DTC code (e.g., P0202). It illustrates categories like Systems (B=Body, C=Chassis, P=Powertrain, U=Network), Sub-systems (e.g., 1=Fuel and Air Metering, 3=Ignition System or Engine Misfire, 6=Computer Output Circuits), Code Type (0=Generic, 1=Manufacturer Specific), and Identifying specific malfunctioning section of the systems.

Tool Description

Image Description: The image shows a handheld Autel MaxiScan MS300 OBD II Scan Tool. It is a gray and black device with an LCD display at the top and control buttons below. Numbered callouts indicate:

• 1. LCD DISPLAY – indicates test results. It is a backlit 2-line display with 8 characters on each line.
• 2. ENTER BUTTON – confirms a selection (or action) from a menu list, or returns to the main menu.
• 3. SCROLL BUTTON – scrolls through menu items or cancels an operation.
• 4. OBD II CONNECTOR – connects the Code Scanner to the vehicle's Data Link Connector (DLC).

Product Specifications

1. Display: backlit LCD, 2 lines, 8 characters each
2. Operating Temperature: 0 to 50°C (32 to 122 F°)
3. Storage Temperature: -20 to 70°C (-4 to 158 F°)
4. Power: DC12V provided via the vehicle's battery
5. Dimensions: Length: 113 mm (4.4") Width: 74 mm (2.9") Height: 21 mm (0.83")
6. Weight: 250g (8.9 oz)

Product Features

• Works with all 1996 and newer cars & light trucks that are OBD II compliant (including the CAN, VPW, PWM, ISO and KWP 2000 protocols)
• Reads and clears generic and manufacturer specific Diagnostic Trouble Codes (DTCs) and turns off check engine light
• Supports multiple trouble code requests: generic codes, pending codes and manufacturer's specific codes
• Reviews the emission readiness status of OBD monitors
• Retrieves VIN (Vehicle Identification No.) on 2002 and newer vehicles that support Mode 9
• Determines the malfunction indicator lamp (MIL) status Easy to use with one plug-in; Highly reliable and accurate Easy-to-read crystal-clear backlit 2-line LCD display
• Stand-alone unit with no need for an additional laptop computer to operate
• Small in size and conveniently fits in your palm
• Safely communicates with the on-board computer
• No batteries needed--powered via detachable OBD II cable

Vehicle Coverage

The MaxiScan OBD II Scan Tool is specially designed to work with all OBD II compliant vehicles, including those equipped with the next-generation protocol-Control Area Network (CAN). It is required by EPA that All 1996 and newer vehicles (cars and light trucks) sold in the United States must be OBD II compliant and this includes all Domestic, Asian and European vehicles.

A small number of 1994 and 1995 model year gasoline vehicles are OBD II compliant. To verify if a 1994 or 1995 vehicle is OBD II compliant, check the Vehicle Emissions Control Information (VECI) Label which is located under the hood or by the radiator of most vehicles. If the vehicle is OBD II compliant, the label will designate “OBD II Certified". Additionally, Government regulations mandate that all OBD II compliant vehicles must have a "common" sixteen-pin Data Link Connector (DLC).

For your vehicle to be OBD II compliant it must have a 16-pin DLC (Data Link Connector) under the dash and the Vehicle Emission Control Information Label must state that the vehicle is OBD II compliant.

Read Codes:

CAUTION: Don't connect or disconnect any test equipment with ignition on or engine running.

1. Turn the ignition off.
2. Locate the 16-pin Data Link Connector (DLC) and plug into the Scan Tool cable connector to the DLC.
3. Wait for the LCD display to read "C.A.N.OBD2".

Display Message: "C.A.N.OBD2"

4. Turn the ignition on. But do not start the engine.
5. Press the ENTER button. A sequence of messages showing the OBD2 protocols will be observed on the display until the vehicle protocol is detected.

Protocol Scanning Diagram: Shows a flowchart of the scan tool detecting the vehicle's OBD2 protocol. Messages like "SCAN... VPW", "SCAN... PWM", "SCAN... CAN", and "ISO9141 PROTOCOL" may appear sequentially. The process stops once the vehicle's protocol is identified and a confirmation message is displayed.

Not all the above messages will be displayed unless protocol of the vehicle being tested is the last one – the ISO9141 protocol. They will stop appearing after the vehicle protocol is detected and a confirmation message of "XXX Protocol" is displayed.

If a "LINK ERROR!" message shows up, turn the ignition off for about 10 seconds, check if the Scan Tool's OBDII connector is securely connected to the vehicle's DLC, and then turn the ignition back to on. Repeat the procedure from step 5. If the “LINK ERROR” message does not go away, then there may be problems for the Scan Tool to communicate with the vehicle.

6. Wait for the main menu to come up after a brief overview displaying the scanning results with the total number of DTCs and the overall I/M Monitor Status.

Display Message: "DTC:02 IM/YES" (example indicating 2 DTCs and I/M readiness status)

7. Select "DTC" from the main menu by pressing the ENTER button.

Menu Selection: "MENU: 1. DTC"

If there are no Diagnostic Trouble Codes retrieved, the display will indicate "NO CODES".

Display Message: "NO CODES"

If there are any Diagnostic Trouble Codes, then the total number of the Fault Codes followed by that of the Pending Codes will be reported on the display.

Display Message: "FAULT: 02 PEND: 02" (example indicating 2 fault codes and 2 pending codes)

8. Read the Diagnostic Trouble Codes by pressing the SCROLL button.

The first code number will appear on the first line of the LCD display, the numerical sequence of the code and the total number of the codes stored will appear on the second line. To view additional codes, press the SCROLL button to scroll, as necessary, until all the codes have been shown up.

Display Example: "P0101 01/04" (Code P0101, 1 of 4 codes)

If the code retrieved is a pending code, a "PD" will show on the LCD display in the end.

Display Example: "P0005 PD 01/05" (Pending Code P0005, 1 of 5 codes)

To view previous codes, press the SCROLL button to scroll through to the end, and then start from the first of the list.

9. Look up part 5 for Diagnostic Trouble Code Definitions. Match the retrieved DTC(S) with those listed and read the definitions.

Erase Codes

CAUTION: Erasing the Diagnostic Trouble Codes allows the Scan Tool to delete not only the codes from the vehicle's on-board computer, but also “Freeze Frame” data and manufacturer-specific enhanced data. Further, the I/M Readiness Monitor Status for all vehicle Monitors is reset to Not Ready or Not Complete status. Do not erase the codes before the system has been checked completely by a technician.

1. If you decide to erase the DTCs, Select "2. ERASE" from the main menu by pressing the ENTER button.

Menu Selection: "MENU: 2. ERASE"

If the Scan Tool is not connected or no communication is established with the vehicle yet, then refer to "Reading Codes" from 1 to 6.

2. A message of “ERASE? YES NO" comes up asking for your confirmation.

Display Prompt: "ERASE? YES NO"

3. If you do not want to proceed with erasing the codes, press the SCROLL button to exit.
4. If you do wish to proceed to erase the codes, then press the ENTER button.
5. If the codes are cleared successfully, an “ERASE DONE!” message will show on the display. Press the ENTER button to Return to the main Menu list.

Display Message: "ERASE DONE!"

6. If the codes are not cleared, then an “ERASE FAIL!” message will appear. Press the ENTER button to Return to the main Menu list.

Display Message: "ERASE FAIL!"

HOT KEY: Press and Hold the SCROLL button for about 3 seconds will allow you to erase the DTCs more quickly than through the main menu.

Retrieve I/M Readiness Status

IMPORTANT: I/M Readiness function is used to check the operations of the Emission System on OBD2 compliant vehicles. It is an excellent function to use prior to having a vehicle inspected for compliance to a state emissions program.

An I/M Readiness Status result of "NO" does not necessarily indicate that the vehicle being tested will fail the state I/M inspection. For some states, one or more such monitors may be allowed to be "Not Ready" to pass the emissions inspection.

• YES – all monitors supported on the vehicle have completed their diagnostic testing and the MIL light is not on
• NO – at least one monitor supported on the vehicle has not completed its diagnostic testing, and (or) the "Check Engine"(MIL) light is on
• READY – indicates that a particular monitor being checked has completed its diagnostic testing
• Not RDY(NOT READY) – indicates that a particular monitor being checked has not completed its diagnostic testing
• N/A – the monitor is not supported on that vehicle
• → (flashing Right Arrow) – indicates additional information is available on the next screen
• ← (flashing Left Arrow) – indicates additional information is available on the previous screen

1. Select "3. I/M" from the main menu by pressing the ENTER button.

Menu Selection: "MENU: 3. I/M"

If the Scan Tool is not connected yet, then refer to "Read Codes" from 1 to 6.

2. Use the SCROLL button to view the status of the MIL light (ON or OFF) and the following monitors:
• MISFIRE – Misfire monitor
• FUEL – Fuel System Monitor
• CCM – Comprehensive Components Monitor
• CAT – Catalyst Monitor
• HCM – Heated Catalyst Monitor
• EVAP – Evaporative System Monitor
• 2AIR – Secondary Air Monitor
• A/C – A/C system Monitor
• O2S – O2 Sensors Monitor
• HO2S – O2 Sensor Heater Monitor
• EGR – EGR System Monitor
3. Press the ENTER button to return to the main Menu.

View VIN Number

The View VIN function allows you to retrieve the Vehicle Identification No. on 2002 and newer vehicles that support Mode 9.

1. Select "4. VIN" from the main menu by pressing the ENTER button.

Menu Selection: "MENU: 4. VIN"

If the Scan Tool is not connected yet, then refer to "Read Codes" from 1 to 6.

2. Use the SCROLL button to view additional digits of the 17-digit string.

→ (flashing Right Arrow) indicates additional digits of VIN string are available on the next screen.

← (flashing Left Arrow) indicates additional digits of VIN string are available on the previous screen.

3. Press the ENTER button to return to the main Menu.

Rescan Data

The RESCAN function allows you to retrieve the most current data stored in the ECM or to re-link to the vehicle if communication is disconnected.

1. Select "5. RESCAN" from the main menu by pressing the ENTER button.

Menu Selection: "MENU: 5. RESCAN"

If the Scan Tool is not connected yet, then refer to "Read Codes" from 1 to 6.

2. Use either the SCROLL or ENTER button to return to the main menu.