Mercedes W204 C220 CDI 170HP M646.811 Engine Unit ECU Kit A6461503734 Key Lock

Mercedes W204 C220 CDI 170HP M646.811 Engine Unit ECU Kit Key Lock is a professional solution for workshops and users who need a functional, factory-matched engine control system. This set from the Electronic control modules and controllers group allows for a consistent replacement of key engine electronics components, minimizing the risk of issues with the immobilizer and vehicle network communication.

Specifications and technical data

• SKU: A6461503734-2
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6461503734
• Substitutable numbers: A6461503734, A 646 150 37 34, A0054467440, A 005 446 74 40, A2075450108, A 207 545 01 08
• Fuel type: Petrol
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Intended use and kit configuration

The presented Mercedes W204 C220 CDI 170HP M646.811 Engine Unit ECU Kit Key Lock is designed for vehicles with a 170 HP diesel engine, designated as M646.811. Integrating the engine controller with the steering lock components and the key significantly facilitates the adaptation process in the car, as the key security system components come from a single set.

This type of solution is particularly useful when replacing a damaged controller, experiencing vehicle starting issues, or when it is necessary to restore a consistent immobilizer system after an electronics failure.

Technical characteristics and compatibility

The kit has been designed to work with a diesel engine and an automatic transmission, which is essential when selecting the appropriate controller for a specific vehicle configuration. Proper matching to the fuel type and transmission type is crucial for the correct operation of functions such as:

• precise fuel dosage and boost pressure control,
• proper cooperation with the automatic transmission,
• support for safety and comfort systems related to engine operation.

Thanks to the use of an original module from the Electronic control modules and controllers group, compatibility with the factory Mercedes electrical architecture is maintained, which limits the need for additional installation modifications.

Practical application in service and repairs

The ECU kit with key and lock is particularly beneficial in situations where:

• the original controller has suffered electrical or software damage,
• there are problems with key recognition and the immobilizer,
• it is necessary to replace several security system elements simultaneously.

The used kit allows for economical vehicle repair while maintaining high-quality components. Simultaneous replacement of the controller, lock, and key reduces diagnostic time and minimizes the risk of coding mismatches between individual modules.

Benefits of choosing an original Mercedes module

By choosing an original engine controller kit for the Mercedes W204, you gain:

• factory fitment to the electrical system – compatibility with the wiring harness, sensors, and other modules in the vehicle,
• consistent security system – the controller, lock, and key come from a single set, which facilitates starting the car after installation,
• stable engine operation – a controller prepared to work with a specific engine type and automatic transmission.

This type of solution is valued by both professional service centers and individual users who expect a predictable repair outcome and a reduction in the risk of additional costs associated with programming.

Mercedes electronic control modules and controllers – expansion and modernization

If you are planning a comprehensive repair or modernization of the engine area in your Mercedes and need other elements from the same group, such as comfort controllers, transmission modules, or safety system controllers, check the available parts in the Mercedes electronic control modules and controllers category.

More about the role of used modules in preserving the brand's character

When selecting used controllers and modules, it is worth noting how original components influence the preservation of driving characteristics and electronics performance in premium class cars. A good point of reference is an article describing the importance of factory components in the Audi brand – you can find it here: Audi and pure emotion – how used parts help maintain the brand's DNA. Although it concerns a different brand, it shows why using original control modules is just as important in a Mercedes.

If you are considering whether it is better to choose a new or used part for advanced components like an engine controller, a guide comparing both options in terms of cost and durability may also be helpful: Car parts – new or used? A comparison of costs, quality, and durability. This will make it easier for you to assess how to choose the optimal solution for your budget and service expectations.