AUTOOL DM303 Electric Circuit Tester with Oscilloscope/Operation/Analog Signal/Fuel Injector Testing. The AUTOOL DM303 Electric Circuit Tester is a new portable multi-measurement diagnostic tool that combines a digital oscilloscope, a digital multimeter, and electrical circuits for vehicles to detect car signals, using built-in digital control technology. To improve logistics and transportation services, the DM303 does not come equipped with batteries. You need to purchase 4 local 1.5 amp batteries. Without the batteries, when disconnected from the charging cable, it will automatically turn off. Features of the AUTOOL DM303 Electric Circuit Tester: 1- A 2.8-inch color display screen allows you to adjust the screen operation, with clear and intuitive data, suitable for a variety of work environments. 2- It can organize the host and accessories well, is easy to carry, and the case is drop-resistant and impact-resistant to effectively protect the tool. 3- The wave testing features a bandwidth of 500 kHz and uses a variable sampling frequency to measure slowly varying signals. It is suitable for automotive maintenance, allowing the monitoring of various signals in vehicle circuits, including engine signals, motor voltage in electric vehicles, ignition signals, camshaft signals, and crankshaft signals in fuel engines. 4- Positioning and wire connecting. The multimeter will automatically select the appropriate measurement based on what it detects. With true RMS value, the portable DM303 multimeter provides you with clear and accurate readings whenever and wherever you need them. 5- Equipped with 8 wire lines for different functions, including a multi-functional test line, a battery clip line, an ignition pulse signal test line, a vehicle circuit test line, a connector, and a multi-measurement probe. The multi-functional test line checks battery voltage, fuel injectors, relays, K-wire signals, CAN, and the vehicle's electronic control unit. 6- Multi-language support with 12 different languages. 7- In case of any damage due to non-human factors, we promise to reissue the parts for free within 3 years. Functions of the AUTOOL DM303 Electric Circuit Tester: 1- Detects voltage up to 1000 volts AC/DC, measures 200 mA of AC/DC current, and detects resistance and diodes. 2- The portable oscilloscope has a bandwidth of 500 kHz. Auto display with one-button press for the measured waveform. 3- Identifies engine cylinder type and ignition and calculates the speed of different engine cylinders. 4- Measurements should be made by connecting to a valid signal source with a voltage greater than 1 volt. 5- The vehicle starting test indicates normal operation if the minimum battery voltage is above 9.6 volts. If it drops below 9.6 volts, this may indicate battery aging. 6- The multimeter can operate the injector for testing and can also detect the injector signal in real-time. It can test electromagnetic injectors, including GDI injectors, but does not support 120-volt injectors. 7- The multimeter can simulate 5-volt square wave signals and 5-volt sine wave signals, and can also connect to the battery for 12-volt square wave signals using a multi-functional detection cable. 8- True RMS measurement technology that automatically enhances accuracy. The True-RMS multimeter is ideal for a wide range of electrical testing applications.