1. Introduction
The AUTOOL DM303 is a versatile hand-held automotive diagnostic multimeter that integrates the functions of a digital oscilloscope and a digital multimeter. Designed with embedded digital control technology, it provides comprehensive diagnostic capabilities for various automotive electrical systems. This device is ideal for professional technicians and automotive enthusiasts for accurate and efficient vehicle maintenance and troubleshooting.
2. Key Features
The AUTOOL DM303 offers a wide range of diagnostic functions:
- DC/AC Voltage Measurement
- DC/AC Current Measurement
- Resistance Test
- Frequency Measurement
- Oscilloscope Test
- Automotive Circuit Test
- Car Start-up Test
- Injector Test
- Automobile Relay Test
- Analog Signal Test
- Ignition Pulse Signal Test
- K/CAN Line Data Analysis
The device features a 2.8-inch color LCD screen with a resolution of 320*240, offering adjustable brightness for clear and intuitive data display in various working environments.
It supports 13 languages: Deutsch, Spanish, French, Italian, English, Japanese, Portuguese, Dutch, Polish, Russian, Korean, Chinese, and Traditional Chinese.
3. Package Contents
The AUTOOL DM303 comes with the following items, neatly stored in a portable toolbox:
- AUTOOL DM303 Main Unit
- Multi-functional Detection Line (C01-1 to C01-SIN, C01-S1, C01-S2)
- Battery Clip Line (C02)
- Ignition Pulse Signal Detection Line (C03)
- Probe Terminal (C04-2)
- Jumper (Black) (C05)
- Jumper (Green) (C06)
- Jumper (Yellow) (C07)
- User Manual
- Portable Toolbox
4. Product Overview
The DM303 is designed for ease of use and durability. Below is an overview of its main components:
- Display screen: 2.8-inch color LCD.
- Power indicator: Indicates device power status.
- Power key: Turns the device ON/OFF.
- Hold key: Freezes the current reading on the screen.
- Direction key: Used for navigation within menus.
- Return key: Navigates back to the previous menu or screen.
- Enter key: Confirms selection or enters a menu.
- 10A current input: Input jack for high current measurements.
- mA/uA measurement input: Input jack for low current measurements.
- Lighting key: Activates the device's built-in light.
- ZERO / F1 Function key: Zeroes readings or acts as Function 1.
- F2 Function key: Acts as Function 2.
- Measurement mode switching: Button to cycle through different measurement modes.
- Diode, voltage, resistance, frequency measurement input: Common input jack for these functions.
- COM measurement input: Common ground input jack.
- DB15 interface: Connector for specialized diagnostic cables.
- SD card slot / data interface: For software updates and data storage.
- Light: Built-in light for illuminating work areas.
- Back bracket: Allows the device to stand upright for hands-free operation.
5. Specifications
| Attribute | Value |
|---|---|
| Model Name | DM303 |
| Brand Name | Autory |
| Origin | Mainland China |
| Certification | CE |
| External Testing Certification | ce |
| Color Screen | 2.8 inch LCD |
| Resolution | 320*240 |
| Voltage Measurement Range | DC 0-1000V, AC 0-700V |
| Current Measurement Range | 0-20A, 0-200mA |
| Resistance Measurement Range | 0-1MΩ |
| Frequency Measurement Range | 1Hz-1MHz |
| Automotive Circuit Drive Current | 0-5A |
| Injector Drive Signal Output | 500-6000rpm |
| Working Temperature | 0~40°C (32~104°F) Humidity: ≤75% |
| Storage Temperature | 10~50°C (14~122°F) Humidity: ≤70% |
| Altitude | 2000m |
| Item Length | 26cm |
| Item Width | 20cm |
| Item Height | 11cm |
| Item Weight | 1.7kg |
| Input Impedance (Voltage) | 2~3MΩ (<160V); 10MΩ (>160V) |
| Max Input Voltage | 1000Vpp |
| Analog Bandwidth | 500KHz |
| 10A Terminal Fuse | 15A self-recovery fuse (Max 20A) |
| mA/uA Terminal Fuse | 0.5A self-recovery fuse (Max 200mA) |
6. Setup Guide
6.1 Battery Installation
The AUTOOL DM303 is not equipped with batteries for logistics and transportation reasons. You will need to purchase 4pcs 1.5A batteries (AA size) or a 3.7V, 1200 mAh lithium battery separately.
- Locate the battery compartment on the back of the device.
- Open the battery compartment cover.
- Insert 4pcs 1.5A batteries, ensuring correct polarity (+/-).
- Close the battery compartment cover securely.
Note: Without batteries, the device will turn off automatically when disconnected from the charging cable.
6.2 Powering On/Off
Press and hold the Power key (labeled '3' in the Product Overview diagram) to turn the device ON or OFF.
7. Operating Instructions
The AUTOOL DM303 features an intuitive interface for selecting and performing various tests. Use the Direction keys (5) to navigate through menus and the Enter key (7) to confirm selections.
7.1 General Navigation
- Use the Direction keys (Up, Down, Left, Right) to move the cursor or change values.
- Press OK (Enter key) to select an option or confirm an action.
- Press ESC (Return key) to go back to the previous screen or cancel an operation.
- Use F1 (ZERO) and F2 for specific function adjustments as indicated on the screen.
- The HOLD key (4) can be used to freeze the current measurement on the display.
7.2 Multimeter Mode
Select 'Multimeter' from the main menu. This mode allows you to measure AC/DC voltage, current, resistance, diode forward voltage drop, on-off continuity, and frequency. Connect the appropriate probes to the device's input jacks (8, 9, 14, 15) and to the circuit under test.
7.3 Oscilloscope Mode
Select 'Oscilloscope' from the main menu. This mode provides a complete intelligent measurement system for signal input, data sampling, processing, and automatic search. It has a waveform test bandwidth of 500KHz and a variable sampling frequency for measuring slowly varying signals. It is suitable for observing various automotive signals such as engine ignition pulse, camshaft, crankshaft, wheel speed sensor, and oxygen sensor signals.
7.4 Automotive Circuit Test
This function allows online testing of low voltage circuits, detection of high voltage or line leakage, and output of power supply voltage. It can also output power voltage to test car components or lower voltage to drive components like lights. It can test battery voltage during vehicle startup to assess the starting system and battery condition.
7.5 Car Start-up Test (Cranking Test)
Connect the device to the vehicle's battery using the appropriate cables. Select 'Cranking Test' from the menu. The device will monitor current and minimum voltage during engine cranking to evaluate the battery and starter motor performance.
7.6 Injector Test
Connect the injector to the device using the specialized terminals (C01-2). Select 'Injector Test' to simulate engine speed and drive the fuel injection nozzle, allowing for functional testing of the injector.
7.7 Automobile Relay Test
Connect the relay to the device using the specialized terminals (C01-2). Select 'Relay Test' to check the output status and contact resistance of the relay.
7.8 Analog Signal Test
This function is used for car ECU detection. It can simulate square wave and sine wave outputs, which can be used to test ECU inputs or drive certain components.
7.9 Ignition Pulse Signal Test
Use the Ignition Pulse Signal Detection Line (C03) to connect to the ignition system. Select 'Ignition Pulse Signal Test' to analyze the ignition pulse waveform and characteristics.
7.10 K/CAN Line Data Analysis
Connect the device to the vehicle's K-line or CAN bus using the appropriate cables (C01-K, C01-CAN+, C01-CAN-). Select 'K/CAN Line Data' to monitor and analyze data signals on these communication lines.
7.11 Frequency Measurement
Select 'Frequency Measurement' from the multimeter mode or a dedicated frequency function. Connect the probes to the signal source to measure its frequency.
8. Maintenance
8.1 Software Upgrading
The instrument supports software updates via an SD card. To update the software:
- Download the latest application software file from the official AUTOOL website.
- Copy the downloaded file to an SD card.
- Insert the SD card into the device's SD card slot (17).
- Follow the on-screen instructions to complete the software update.
8.2 Cleaning and Storage
- Keep the device clean and dry. Use a soft, damp cloth to wipe the exterior. Do not use abrasive cleaners or solvents.
- Ensure all ports and connectors are free from dust and debris.
- When not in use, store the main unit and all accessories in the provided portable toolbox. The toolbox is designed to protect the instrument from falls and impacts.
9. Troubleshooting
- Device does not power on: Check if batteries are correctly installed and charged. Ensure the power key is pressed and held sufficiently.
- Inaccurate readings: Verify that all connections are secure and probes are properly attached to the circuit. Ensure the correct measurement mode is selected.
- Screen is dim or unreadable: Adjust the screen brightness through the device settings.
- Device freezes or becomes unresponsive: Try restarting the device by holding the power key. If the issue persists, ensure the software is up to date.
10. User Tips
- Always ensure the device is powered off before connecting or disconnecting probes to prevent accidental short circuits or damage.
- For precise current measurements, especially low currents, ensure the circuit is properly isolated and the correct input jack (10A or mA/uA) is used.
- When using the oscilloscope function, familiarize yourself with typical waveforms for the components you are testing to quickly identify anomalies.
- Utilize the back bracket (19) for hands-free operation, especially when working in tight engine compartments.
11. Warranty and Support
The AUTOOL DM303 comes with a 3-year warranty, ensuring quality assurance. For technical support, service, or warranty claims, please contact your authorized AUTOOL dealer or visit the official AUTOOL website for contact information.
