1. Introduzzjoni
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. Karatteristiċi ewlenin
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 sampfrekwenza tal-linarda.
- Automotive Specific Tests: Automotive Circuit Test, Cranking Test, Injector Test, Relay Test, Analog Signal Test, Ignition Signal Test, K/CAN Line Data analysis.
- Wiri: 2.8-inch color LCD with 320*240 resolution and adjustable brightness.
- Appoġġ Multilingwi: English, Russian, French, Italian, German, Spanish, Portuguese, Polish, Dutch, Japanese, Korean, Chinese.
- Portabbiltà: Comes with a durable portable toolbox for easy storage and protection.
- Software Upgradable: Supports application software updates via SD card.

Figura 2: Aktarview of the 12 test functions available on the DM303.
3. Kontenut tal-Pakkett
The AUTOOL DM303 package includes the following items:
- AUTOOL DM303 Main Unit
- Kaxxa tal-Għodda Portabbli
- Manwal għall-Utent
- Various Detection Lines and Probes:
| Nru. | Isem | Kap tad-Distribuzzjoni Nru. | Funzjonijiet |
|---|---|---|---|
| 1 | Linja ta 'skoperta multi-funzjonali | C01-1 | Konnettur DC, imqabbad mal-linja tal-klipp tal-batterija |
| C01-2 | Injector / relay test terminals | ||
| C01-K | Linja tas-sinjal tal-linja K | ||
| C01-CAN+ | CAN + linja tas-sinjal | ||
| C01-CAN- | CAN- linja tas-sinjal | ||
| C01-GND | Wajer mitħun | ||
| C01-SIN | Linja tas-sinjal tal-mewġ tas-sinus | ||
| C01-S1 | Linja tas-sinjal 5V | ||
| C01-S2 | Linja tas-sinjal kwadru | ||
| 2 | Linja ta 'skoperta ta' ċirkwit tal-karozzi | C02-1 | Konnettur DC, imqabbad mal-linja tal-klipp tal-batterija |
| C02-2 | Terminal tas-sonda | ||
| 3 | Ignition signal detection line | Inductive high-voltage sinjal | |
| 4 | Linja tal-klipp tal-batterija | Qabbad il-batterija | |
| 5 | Jumper (Yellow) | Connect multiple circuit connectors | |
| 6 | Jumper (Green) | Connect multiple circuit connectors | |
| 7 | Jumper (Black) | Connect multiple circuit connectors | |
| 8 | Sonda | Circuit measurement |

Figura 3: Dettaljat view of the various detection lines and their applications.
4. Prodott Aktarview
Familiarize yourself with the components and controls of the AUTOOL DM303:

Figure 4: AUTOOL DM303 device layout and labeled parts.
- Skrin tal-wiri
- Indikatur tal-qawwa
- Ċavetta tal-enerġija
- Żomm iċ-ċavetta
- Ċavetta tad-direzzjoni
- Ċavetta tar-ritorn
- Daħħal iċ-ċavetta
- Input kurrenti 10A
- Input tal-kejl mA/uA
- Ċavetta tad-dawl
- ZERO / F1 Function key
- Ċavetta tal-funzjoni F2
- Qlib tal-mod tal-kejl
- Diode, voltage, reżistenza, input tal-kejl tal-frekwenza
- Input tal-kejl COM
- Interface DB15
- SD card slot / data interface
- Dawl
- Parentesi tad-dahar
5. Setup Inizjali
5.1 Installazzjoni tal-batterija
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 Settings tal-Lingwa
L-apparat jappoġġja diversi lingwi. Biex tibdel il-lingwa:
- Ixgħel l-apparat.
- Navigate to the 'Basic Setting' menu using the direction keys.
- Select 'Language Setting' and choose your preferred language from the list (English, Russian, French, Italian, German, Spanish, Portuguese, Polish, Dutch, Japanese, Korean, Chinese).
- Ikkonferma l-għażla tiegħek.

Figure 5: Language selection screen on the DM303.
5.3 Aġġustament tal-luminożità tal-iskrin
The 2.8-inch color display's brightness can be adjusted for optimal visibility in various working environments.
- Navigate to the 'Basic Setting' menu.
- Select 'Brightness' and adjust to your desired level.

Figure 6: Basic settings menu for screen brightness.
6. Istruzzjonijiet Operattivi
The AUTOOL DM303 offers a variety of diagnostic modes. Select the appropriate mode from the main menu using the direction keys and 'OK' button.
Video 1: Demonstration of AUTOOL DM303 performing various diagnostic tests on a vehicle.
6.1 Funzjonijiet tal-Multimetru
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 fuq 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).
- Kejl tar-Reżistenza: Measure the resistance of components.
- Kejl tal-Frekwenza: Determine the frequency of electrical signals.
- Test tad-Diode: 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 Test tal-Krankjar
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.

Figura 7: Eżamples of the DM303 interface display for different test functions.
7. Speċifikazzjonijiet
| Attribut | Speċifikazzjoni |
|---|---|
| Isem tal-Mudell | DM303 |
| Isem tad-Ditta | AUTOOL |
| Display Screen | Skrin LCD bil-kulur ta' 2.8 pulzieri |
| Riżoluzzjoni | 320 * 240 |
| Voltage Medda ta' Kejl | DC 0-1000V, AC 0-700V |
| Firxa tal-Kejl kurrenti | 0-20A, 0-200mA |
| Firxa tal-Kejl tar-Reżistenza | 0-1MΩ |
| Medda ta' Kejl tal-Frekwenza | 1Hz-1MHz |
| Automotive Circuit Drive Current | 0-5A (Maximum Output) |
| Injector Drive Signal Output | 500-6000rpm |
| Max Input Voltage (Oscilloscope) | 1000Vpp |
| Analog Bandwidth (Oscilloscope) | 500KHz |
| Input Impedance (Voltage Kejl) | 2~3MΩ (<160V), 10MΩ (>160V) |
| 10A Terminal Fuse | 15A fjus li jirkupra lilhom infushom |
| mA/uA Terminal Fuse | 0.5A fjus li jirkupra lilhom infushom |
| Temperatura tax-Xogħol | 0 ~ 40 ° C (32 ~ 104 ° F) |
| Umdità tax-Xogħol | ≤75% |
| Temperatura tal-Ħażna | 10 ~ 50 ° C (14 ~ 122 ° F) |
| Umdità tal-Ħażna | ≤70% |
| Altitudni | 2000m |
| Piż tal-oġġett | 1.7kg |
| Dimensjonijiet tal-oġġett (L x W x H) | 26cm x 20cm x 11cm |
| Ċertifikazzjoni ta' Ittestjar Estern | CE |
| Oriġini | Iċ-Ċina kontinentali |

Figure 8: DM303 product dimensions and key specifications.
8 Issolvi l-problemi
- Apparat mhux mixgħul: Ensure batteries are correctly installed and charged, or that the device is connected to a power source.
- L-ebda wiri jew wiri mċajpar: Adjust screen brightness in the 'Basic Setting' menu.
- Qari mhux korrett: 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. Għajnuniet għall-Utenti
- Tħejjija tal-Batterija: 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: Ħu bil-quddiemtage of the multilingual support to set the device to your native language for easier operation.
- Aġġornamenti tas-Software: 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.
- Ġestjoni tal-Kejbil: Utilize the provided portable toolbox to keep all cables and accessories organized and protected, extending their lifespan.
10. Manutenzjoni
- Ħażna: 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.
- Kundizzjonijiet Ambjentali: 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%.
- Tindif: Naddaf l-apparat b'ċarruta ratba u niexfa. Tużax prodotti tat-tindif jew solventi li joborxu.
- Aġġornamenti tas-Software: 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. Garanzija u Appoġġ
11.1 Informazzjoni dwar Garanzija
All AUTOOL products purchased from an authorized AUTOOL store come with a garanzija ta 'senaDin il-garanzija tkopri difetti fil-manifattura u tiżgura l-kwalità tal-prodott tiegħek.
11.2 Appoġġ Tekniku
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.





