Feature: 1. Applicable Model: The engine control unit is for replacement for Benz C280 C300. Please confirm whether it is consistent with the product you want before buying to avoid unnecessary return. 2. OE Number: The part numbers for reference are A2721530991, 2721530991. Please confirm whether it is consistent with the OE you need to avoid wrong buying and other problems. 3. Premium Material: The engine control module is made of durable aluminum alloy shell and precise welded internal circuit board to prevent vibration and wear, ensuring stable operation and long lifespan. 4. Precise Control and High Efficiency: The engine control module control engine working status, analyzing and adjusting to improve fuel economy, reduce emissions, and ensuring long lasting stable use. 5. Protective and Stable Performance: The engine control module ECU adopts excellent anti interference ability and provide reliable protection, can work normally in harsh working environments. Specification: Item Type: Engine Control Module ECU Installation Type: Direct Replacement of Original Parts OE Number: A2721530991, 2721530991 Fitment: Replacement for Benz C280 C300 Functions and Applications: 1. Control the working state of the engine: The engine control module is the core device for engine control. It analyzes and controls the engine by receiving signals from sensors to achieve better fuel economy, reduce emissions, and protect the engine. 2. Strong protection and anti interference ability: The engine control module adopts precise hardware components and efficient software algorithms, with strong anti interference ability and high reliability, can work normally in harsh working environments. 3. Complete functions, strong scalability: The engine control module has rich functions and interfaces, can communicate and integrate with other vehicle systems (such as transmission, ABS, in vehicle entertainment systems, etc.) to achieve intelligent vehicle control; Installation Notes: 1. It is recommended to find a professional automotive engineer for installation. Programming is required before installation. 2. When installing the product, check the cause of the previous damage to the engine control module to avoid damaging the module again due to the same fault. 3. Check whether the voltage is normal before installing the module (voltage is around 12V), it is not recommended to install if it is above 15V. Check the wiring and grounding to avoid possible damage to the module. 4. After installing the computer board (insert the plug for trial operation), the key is turned on and off to the NO position three or four times before starting. 5. If the vehicle has an anti theft function, it needs to be decoded (matched) before it can be installed, which will depend on your car rather than the computer board. Correct installation method of computer board: 1. First remove a fire wire from the battery wire, then install the computer board (circuit board) on it, and then connect the battery wire. 2. Put the car key on NO, do not leave the car, wait 1-2 minutes before ignition. 3. If the last time it does not catch fire, repeat the previous step, or check whether there is dust inside the plug of the computer board, if there is, you can clean it with a clean brush, or check whether the pin is neat, so that the computer board is basically installed. Common troubleshooting methods: 1. If the fault indicator is on, the sensor is faulty. 2. Repeatedly burn the computer board ECU or cannot afford to refuel, please check whether the generator voltage is normal. 3. There is a lack of cylinder situation, check whether the spark plug, ignition line, fuel nozzle, etc., is normal. 4. If the idle speed is unstable, please check whether the idle motor and throttle valve body are normal and have foreign bodies. 5. If the startup is difficult, check whether the pressure sensor and water temperature sensor are normal. 6. If the crankshaft cannot be started, check whether the crankshaft position sensor Speed Sensor is normal. Circuit board basics: 1. Product installation: Confirm the product model and specifications match, install and fix the new circuit board, connect the wiring harness connector, repeatedly switch the ignition switch 3-5 times switching time 2-3, closing time 4-6. 2. Check after installing the computer board: 1) Whether the idle speed runs normally, heat engine 800-950 RPM, cold machine 1000-1300 RPM. 2) Whether the electronic fan works normally, 85℃ open, 90℃ close. 3) Whether the air conditioner runs normally. Open idle speed increased to 1100-1300 RPM. 4) Whether the exhaust gas of the heat engine is normal, If it is abnormal, please check the pressure sensor. 5) If there is idle speed, please adjust the ignition Angle properly.. Package List: 1 x Engine Control Unit Note: Please double check the part number of your item, matching information is for reference only.