Mercedes C209 220 CDI M646.966 150HP Engine ECU Kit A6461506479 + Key + Lock

Mercedes C209 220 CDI M646.966 150HP Engine ECU Kit + Key + Lock is a complete engine electronics package designed for the 150HP M646.966 unit. This solution allows for a seamless replacement of the ECU along with the immobilizer components, which facilitates the restoration of proper powertrain operation and reduces the risk of vehicle starting issues.

Specifications and technical data

• SKU: A6461506479-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6461506479
• Substitutable numbers: A6461506479, A 646 150 64 79, 0281012340, 0 281 012 340, A2034621130, A 203 462 11 30, A2095451908, A 209 545 19 08
• Fuel type: Petrol
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and function of the ECU kit

The presented kit includes an electronic engine control module along with a matched key and lock, ensuring the integrity of the vehicle's security system. The ECU is dedicated to the M646.966 diesel engine family in the C209 body, paired with an automatic transmission. As a result, the entire powertrain control system, including gear shift logic, remains consistent with the vehicle's factory configuration.

The system is designed to work with the 150HP power unit, which guarantees appropriate fuel injection, boost, and engine protection maps. Using a complete ECU kit with immobilizer components reduces the need for time-consuming programming from scratch and allows for a more predictable repair process.

Compatibility and technical parameters

The engine control unit kit is intended for Mercedes vehicles with the M646.966 engine in an automatic transmission configuration. The ECU design is optimized for operation with a diesel engine injection system; however, the product data indicates fuel type: gasoline – before purchasing, it is worth verifying your vehicle's configuration to select the correct variant for your specific engine type.

The electronic control module belongs to the Electronic control modules and ECUs group, meaning it is responsible for processing signals from sensors, controlling fuel injection, engine accessory operation, and communicating with other vehicle systems via data buses. Using an original ECU from the same reference family increases the chance of full compatibility with the electrical installation and equipment of a specific vehicle.

Benefits of using a complete ECU kit

Choosing a complete ECU kit with a key and lock offers a number of practical advantages:

• consistency of the immobilizer system and engine ECU,
• reduction of programming scope to the necessary minimum,
• better predictability of engine starting after installation,
• preservation of automatic transmission operating logic,
• possibility of effective repair after engine electronics failure.

The product comes from dismantling, which allows for an economical restoration of vehicle efficiency while maintaining the original electronic architecture. A used engine ECU is often a reasonable alternative to new components, especially in the case of older model generations where the availability of factory-new parts may be limited.

Selecting a used ECU and practical issues

Before purchasing, it is worth comparing your car's configuration with the offered kit – especially regarding the engine type, fuel type, and transmission used. It is also important to pay attention to the ECU part number family and compatibility with the vehicle's installation; in case of doubt, consulting an automotive electrician or diagnostician is a good solution.

If you want to better understand when choosing a used engine ECU is cost-effective, how to assess its suitability, and what to pay attention to during installation, check out our guide: The second life of electronics – when is it worth opting for used engine ECUs, comfort modules, and parking sensors?. The article discusses the practical aspects of purchasing electronics from dismantling and helps reduce the risk of choosing the wrong part.

Expanding the control system in a Mercedes

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other components from the same group, such as additional controllers, engine management modules, or related electronic units, check the available parts in the Mercedes electronic control modules and ECUs category.

Using consistent electronic components within a single vehicle facilitates diagnostics, improves communication stability between modules, and allows for maintaining the factory characteristics of the powertrain. This makes the repair more predictable, and the vehicle retains driving properties close to the manufacturer's original specifications.