Mercedes W169 W245 180 CDI OM640.940 109HP Engine ECU Kit A6409004900 Key Lock

Complete Engine Control Unit (ECU) with Ignition Switch and Key for Mercedes W169 / W245 180 CDI is a practical service solution for the OM640.940 engine with 109 HP and automatic transmission. This set belongs to the Electronic Control Modules and Controllers group, allowing for a cohesive replacement of key electronic components responsible for the diesel engine's operation.

Specifications and technical data

• SKU: A6409004900-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6409004900
• Substitutable numbers: A6409004900, A 640 900 49 00, 0281018018, 0 281 018 018
• Fuel type: Diesel
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Application and Compatibility

The presented ECU set is designed for Mercedes A-Class W169 and B-Class W245 models in the 180 CDI version with the OM640.940 engine. The set is configured for Diesel drive and automatic transmission, which is important when selecting a controller for a specific vehicle powertrain configuration.

By maintaining the consistency of electronic components (engine control unit, ignition switch, key, lock), the risk of immobilizer issues, CAN network communication problems, and software matching to a specific engine version is minimized.

ECU Set Construction and Installation Benefits

The set includes the engine control unit from the Electronic Control Modules and Controllers group along with vehicle security elements (ignition switch and key), allowing for replacement as a complete set without the need for programming individual components. This solution is particularly beneficial in case of ECU failure, engine starting problems, or immobilizer system damage.

The main advantages of using a complete set include:

• consistency of electronic components within a single vehicle,
• reduced time required for diagnostics and programming,
• decreased risk of software incompatibility with the car's configuration,
• possibility of quick functional verification after installation.

Operation Characteristics with Diesel Engine and Automatic Transmission

The control unit in this set is prepared to handle a diesel engine, thus managing parameters typical for Diesel engines, such as fuel injection quantity, boost pressure, and injection system control. Simultaneously, it communicates with the automatic transmission, meaning it exchanges data with the transmission control module regarding torque, gear changes, and drive strategy.

A correctly selected ECU set for an automatic version contributes to smooth gear changes, stable idle RPM, and predictable vehicle behavior during acceleration and engine braking.

Condition and Service Purpose

The product is offered as a used set of engine control unit with key and lock, which is a cost-effective solution for repairing vehicles used intensively or with higher mileage. This type of set is particularly useful in situations where the existing ECU has suffered electronic damage, water ingress, or its repair is not economically viable.

Before installation, standard vehicle diagnostics and verification of engine and gearbox configuration compatibility are recommended to fully utilize the set's potential and avoid additional adaptation work.

Control System Expansion and Related Components

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other parts from the same group, such as additional control units, comfort modules, or engine management systems, check the available parts in the Mercedes Electronic Control Modules and Controllers category.

To compare manufacturers' approaches to preserving brand character and the role of original electronic modules in modern cars, it is worth reading an article describing how appropriately selected components affect vehicle behavior – more information can be found in the post Audi and Pure Emotion. How Used Parts Help Maintain Brand DNA?.