BMW E46 320Ci 320i M54 Engine Control Unit ECU DME MS43 7551615 Automatic

BMW E46 320Ci 320i M54 Engine Control Unit ECU DME MS43 is a factory-fitted computer controlling the engine operation in versions with an automatic transmission. This component from the Computers and Controllers group is responsible for precise management of the M54 engine parameters, ensuring stable performance, correct communication with other modules, and proper cooperation with the automatic gearbox. By using an original controller, you maintain the integrity of the vehicle's electronics and minimize the risk of compatibility issues.

Specifications and technical data

• SKU: 7545422
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7545422
• Substitutable numbers: 12147545422 12147551615 5WK90027, 7545422 7551615, ŁS
• Gearbox type: Automatic
• Category: Control Modules

Purpose and function of the engine controller

The presented controller is dedicated to BMW 3 Series E46 models in 320Ci and 320i versions with the M54 engine, in a configuration with an automatic transmission. As a DME MS43 unit, it is responsible for controlling fuel injection, ignition, engine auxiliary equipment, and data exchange with other vehicle modules. A correctly selected control computer allows for maintaining factory engine maps, which translates into predictable performance, correct throttle response, and stable idle operation.

Compatibility and reference numbers

The item has a dedicated OEM part number and a set of interchangeable numbers, which facilitates the selection of the correct controller for a specific car configuration. This allows for precise matching of the module to the equipment version, engine type, and the automatic transmission used. Verification by part number or reference numbers helps avoid communication problems in the CAN network, engine operation errors, or software incompatibility with other modules.

Benefits of using an original BMW controller

Choosing an original controller from the BMW Computers and Controllers group ensures:

• preservation of the factory M54 engine control logic,
• proper cooperation with the automatic transmission,
• consistency with other electronic modules in the vehicle,
• easier diagnostics using dedicated BMW service tools.

A used controller is a cost-effective solution that allows you to restore the efficiency of the powertrain without the need to invest in a new module. With proper selection and potential software adaptation, it can effectively replace a damaged engine computer.

Condition, installation, and technical aspects

The offered controller is a used item, which in practice means that before installation, standard service procedures should be anticipated, such as matching the software to the specific vehicle, potential coding, or synchronization with the immobilizer. Due to the cooperation with the automatic transmission, it is particularly important to select a module compatible with the car's configuration and to follow the installation procedures recommended for BMW electronics.

When replacing the ECU, it is worth ensuring:

• thorough checking of the OEM part number and interchangeable numbers,
• verification of the engine and transmission type,
• performing adaptation and clearing errors after installation,
• checking the electrical installation for previous faults.

Technical support and electronics selection

If you are considering using a used engine controller and want to better understand the differences between individual modules, selection by OEM number, and the potential benefits of purchasing parts from the secondary market, check out the guide Second life of electronics – when is it worth choosing used engine controllers, comfort modules, and parking sensors?, where you will find practical tips regarding ECUs and other electronic components.

Expansion of the control system in BMW

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other elements from the same group, such as additional controllers, management modules, or ECU units, check the available parts in the BMW Computers and Controllers category.

For drivers analyzing the cost-effectiveness of purchasing new parts, replacements, and used parts, the article Original, replacement, or used – which car parts are the most cost-effective? may also be helpful, in which cost differences, quality issues, and matching by OEM number are discussed.