AUTOOL DM303 Auto Diagnostic Multimeter User Manual

1. Introduction

The AUTOOL DM303 is a hand-held, advanced diagnostic oscillometric multimeter designed for automotive applications. It integrates the functionalities of a digital oscilloscope and a digital multimeter, utilizing embedded digital control technology to provide comprehensive vehicle circuit testing and analysis. This manual provides detailed instructions for the proper use and maintenance of your DM303 device.

Figure 1: AUTOOL DM303 Auto Diagnostic Multimeter with included accessories.

2. Key Features

The AUTOOL DM303 offers a wide range of diagnostic and measurement capabilities:

• Multimeter Functions: DC/AC Voltage Measurement, DC/AC Current Measurement, Resistance Measurement, Frequency Measurement, Diode Test.
• Oscilloscope Test: Waveform analysis with 500KHz bandwidth and variable sampling frequency.
• Automotive Specific Tests: Automotive Circuit Test, Cranking Test, Injector Test, Relay Test, Analog Signal Test, Ignition Signal Test, K/CAN Line Data analysis.
• Display: 2.8-inch color LCD with 320*240 resolution and adjustable brightness.
• Multilingual Support: English, Russian, French, Italian, German, Spanish, Portuguese, Polish, Dutch, Japanese, Korean, Chinese.
• Portability: Comes with a durable portable toolbox for easy storage and protection.
• Software Upgradable: Supports application software updates via SD card.

Figure 2: Overview of the 12 test functions available on the DM303.

3. Package Contents

The AUTOOL DM303 package includes the following items:

• AUTOOL DM303 Main Unit
• Portable Toolbox
• User Manual
• Various Detection Lines and Probes:

Figure 3: Detailed view of the various detection lines and their applications.

4. Product Overview

Familiarize yourself with the components and controls of the AUTOOL DM303:

Figure 4: AUTOOL DM303 device layout and labeled parts.

1. Display screen
2. Power indicator
3. Power key
4. Hold key
5. Direction key
6. Return key
7. Enter key
8. 10A current input
9. mA/uA measurement input
10. Lighting key
11. ZERO / F1 Function key
12. F2 Function key
13. Measurement mode switching
14. Diode, voltage, resistance, frequency measurement input
15. COM measurement input
16. DB15 interface
17. SD card slot / data interface
18. Light
19. Back bracket

5. Initial Setup

5.1 Battery Installation

The DM303 is not equipped with batteries upon purchase. You will need to acquire 4x 1.5A batteries or a 3.7V, 1200 mAh lithium battery locally. Ensure correct polarity when installing batteries. The device will automatically turn off if disconnected from the charging cable without batteries installed.

5.2 Language Settings

The device supports multiple languages. To change the language:

1. Power on the device.
2. Navigate to the 'Basic Setting' menu using the direction keys.
3. Select 'Language Setting' and choose your preferred language from the list (English, Russian, French, Italian, German, Spanish, Portuguese, Polish, Dutch, Japanese, Korean, Chinese).
4. Confirm your selection.

Figure 5: Language selection screen on the DM303.

5.3 Screen Brightness Adjustment

The 2.8-inch color display's brightness can be adjusted for optimal visibility in various working environments.

1. Navigate to the 'Basic Setting' menu.
2. Select 'Brightness' and adjust to your desired level.

Figure 6: Basic settings menu for screen brightness.

6. Operating Instructions

The AUTOOL DM303 offers a variety of diagnostic modes. Select the appropriate mode from the main menu using the direction keys and 'OK' button.

6.1 Multimeter Functions

Access the Multimeter mode to perform standard electrical measurements:

• Voltage Measurement (DC/AC): Connect the probes to the circuit to measure voltage. The input impedance is 2~3MΩ for voltages below 160V and 10MΩ for voltages above 160V.
• Current Measurement (DC/AC): Use the 10A terminal for currents up to 20A (protected by a 15A self-recovery fuse) or the mA/uA terminal for currents up to 200mA (protected by a 0.5A self-recovery fuse).
• Resistance Measurement: Measure the resistance of components.
• Frequency Measurement: Determine the frequency of electrical signals.
• Diode Test: Check the functionality of diodes.

6.2 Oscilloscope Test

The Oscilloscope mode provides a comprehensive intelligent measurement system for signal analysis. It features a waveform test bandwidth of 500KHz and a variable sampling frequency, allowing for the measurement and observation of various automotive signals, including:

• Motor drive signals and motor power voltage in new energy vehicles.
• Fuel car engine ignition pulse signals.
• Camshaft and crankshaft signals.
• Wheel speed sensor signals.
• Oxygen sensor signals.

6.3 Automotive Circuit Test

This function allows for general testing of automotive circuits to identify faults.

6.4 Cranking Test

Perform a cranking test to assess battery and starter performance during engine startup. The device displays current, minimum voltage, and start voltage, comparing them against a minimum value of 9.6V.

6.5 Injector Test

Test the operation of fuel injectors by simulating engine speed (e.g., 1000 RPM) and checking the output signal.

6.6 Relay Test

Verify the functionality of automotive relays by checking their output status and contact resistance.

6.7 Analog Signal Test

Generate and test analog signals, including sine wave and square wave outputs, with adjustable frequency and duty cycle.

6.8 Ignition Signal Test

Analyze ignition pulse signals to diagnose ignition system issues.

6.9 K/CAN Line Data

Monitor and analyze K/CAN line data for communication diagnostics within the vehicle's network.

Figure 7: Examples of the DM303 interface display for different test functions.

7. Specifications

Figure 8: DM303 product dimensions and key specifications.

8. Troubleshooting

• Device not powering on: Ensure batteries are correctly installed and charged, or that the device is connected to a power source.
• No display or dim display: Adjust screen brightness in the 'Basic Setting' menu.
• Incorrect readings: Verify that the probes are correctly connected to the appropriate input terminals and that the correct measurement mode is selected. Check for damaged cables or probes.
• Difficulty with K/CAN line data: Ensure proper connection to the vehicle's K/CAN lines. Refer to the vehicle's service manual for specific wiring diagrams.
• Testing 24V circuits: The DM303 supports DC voltage measurement up to 1000V, so it is suitable for testing 24V circuits.
• Injector testing for high-pressure injectors: The Injector Test function provides signal output for injector operation. While it simulates engine speed (500-6000rpm), specific voltage requirements for high-pressure injectors (e.g., 75V) are not explicitly stated as a direct output capability. Always refer to the vehicle's specifications for compatibility.

9. User Tips

• Battery Preparation: Remember that the DM303 does not include batteries. Purchase 4x 1.5A batteries or a 3.7V, 1200 mAh lithium battery before first use.
• Language Customization: Take advantage of the multilingual support to set the device to your native language for easier operation.
• Software Updates: Regularly check the AUTOOL Official Store website for software updates. Updates can be installed via an SD card to ensure your device has the latest features and improvements.
• Cable Management: Utilize the provided portable toolbox to keep all cables and accessories organized and protected, extending their lifespan.

10. Maintenance

• Storage: Always store the DM303 and its accessories in the provided portable toolbox when not in use. This protects the instrument from physical damage due to falling or crashing.
• Environmental Conditions: Operate the device within the specified working temperature of 0~40°C (32~104°F) and humidity ≤75%. For storage, maintain temperatures between 10~50°C (14~122°F) and humidity ≤70%.
• Cleaning: Clean the device with a soft, dry cloth. Do not use abrasive cleaners or solvents.
• Software Updates: Keep the device's software updated by downloading the latest versions from the AUTOOL website and installing them via an SD card.

Figure 9: The portable toolbox helps protect your DM303.

11. Warranty and Support

11.1 Warranty Information

All AUTOOL products purchased from an authorized AUTOOL store come with a 3-year warranty. This warranty covers manufacturing defects and ensures the quality of your product.

11.2 Technical Support

AUTOOL Official Store provides lifetime technical support for the DM303. If you encounter any issues or have questions regarding the operation of your device, please contact our customer service. All emails will be answered within 24 hours.