Mercedes W169 W245 OM640.940 109HP Engine Control ECU Kit A6401503634 Automatic

Mercedes W169 W245 OM640.940 109HP Engine Control ECU Kit Automatic is a specialized, used ECU module designed for diesel units paired with an automatic transmission. As an item in the Electronic control modules and controllers category, it is responsible for precise engine management, ensuring stable power characteristics and proper cooperation with the drivetrain. This is a solution for users looking for proven, factory-grade electronics instead of random replacements.

Specifications and technical data

• SKU: A6401503634-2
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6401503634
• Substitutable numbers: A6401503634, A 640 150 36 34, 0281015122, 0 281 015 122, A1695452108, A 169 545 21 08, A1695452932, A 169 545 29 32
• Fuel type: Diesel
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and function of the controller

The presented engine controller is designed to work with a Diesel unit, which means it is matched to the operating characteristics of compression-ignition engines – including fuel dosing, boost pressure control, and exhaust emission control. The module is configured for an automatic transmission, allowing it to correctly exchange data with the transmission control system, supporting smooth gear shifts and stable operation under various loads.

As a component dedicated to Mercedes W169 and W245 series vehicles, the controller integrates with the vehicle's factory electrical architecture, communicating with other modules via the data bus. It is responsible for, among other things:

• real-time monitoring of engine operating parameters,
• coordinating cooperation with the automatic transmission,
• handling safety strategies and emergency modes,
• monitoring sensors and auxiliary actuators.

Advantages of using an original ECU module

Choosing an original controller from the Electronic control modules and controllers group allows you to maintain the factory logic of the drivetrain. A properly selected ECU module reduces the risk of software compatibility issues, communication errors on the bus, or improper cooperation with the automatic transmission. This is particularly important in modern diesels, where many functions – from starting to exhaust system regeneration – are closely linked to the control electronics.

A used engine controller can be an attractive cost-effective solution while maintaining factory build quality and fitment for a specific vehicle configuration. In practice, this means the ability to restore the correct operation of the power unit without the need for costly replacement of the entire assembly.

Selection, compatibility, and programming

When selecting this type of module, it is crucial to match it based on manufacturer markings, hardware and software versions, and vehicle configuration (fuel type, transmission type, electrical system generation). The engine controller in Mercedes W169 and W245 series cars usually requires appropriate adaptation or programming for a specific vehicle using specialized diagnostic equipment.

To facilitate the correct selection and installation of a used ECU, it is worth using a practical guide that discusses, among other things, selection by part numbers, HW/SW compatibility, and basic installation principles. Detailed information can be found in the article Used automotive electronics on board – why is it worth choosing second-hand ECU modules and sensors?.

Benefits of choosing a used OEM controller

A used, original ECU module is a compromise between cost and maintaining factory engine performance parameters. Compared to many replacements, a controller coming from the same product line as the factory-installed one usually:

• works better with the existing electrical installation and other modules,
• reduces the risk of needing to modify wiring harnesses or connectors,
• facilitates diagnostics and software updates at a service center.

If you are considering a wider use of used OEM components in your car, a guide describing practical selection criteria and examples from popular models may be helpful: 5 reasons why a used OEM part is a better choice than a replacement.

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 ECU modules, auxiliary controllers, or electronic accessory controllers, check out the available parts in the Mercedes electronic control modules and controllers category.