BMW 1 3 Series E87 E90 120i 320i N46 ECU Kit DME CAS2 2 Keys 7545042 Manual

BMW 1 3 Series E87 E90 120i 320i N46 ECU Kit DME CAS2 2 Keys is a factory-original electronic engine control unit designed for the N46 engine in the 120i model. As part of the Electronic control modules and ECUs group, it is responsible for precise engine management, ensuring stable power characteristics and proper integration with other vehicle systems. This used DME unit is a sensible solution for repairs where compatibility with the original installation and an optimal cost-to-functionality ratio are essential.

Specifications and technical data

• SKU: 7545042-4
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7545042
• Substitutable numbers: 12147557291, 7557291, 12147552177, 7552177, 12147552176, 12147550535, 12147550534, 7550534, 12147545043, 7545043, 12147545042, 7545042, 61356943759, 6943759, KZ
• Gearbox type: Manual
• Category: ECUs & Computer Modules

Purpose and function of the DME unit

The DME engine computer in the BMW 1 Series E87 with the N46 120i engine acts as the central module managing engine operation. It controls, among other things, fuel injection, ignition timing, auxiliary equipment operation, and communication with other vehicle modules. This allows the engine to maintain stable operating parameters, ensuring that throttle response remains predictable and consistent. A properly selected DME unit allows for the preservation of the engine's factory characteristics, which translates into consistent powertrain operation, proper functioning of OBD diagnostic systems, and correct integration with the vehicle's electrical system.

Compatibility and technical fitment

The presented engine computer is intended for use in the BMW E87 120i with an N46 engine and a manual transmission. Proper matching to the specific drivetrain configuration is crucial to avoid bus communication issues, auxiliary control errors, and engine performance irregularities. In practice, this means that:

• the unit is compatible with the wiring harness and sensors designed for this engine version,
• it is prepared for operation with a manual transmission, which is significant for torque management logic,
• it maintains the factory communication architecture with other electronic modules in the vehicle. As a result, installation proceeds in an orderly manner, and after proper programming and adaptation, it is possible to restore full functionality to the engine control system.

Application of a used engine control unit

Choosing a used DME engine computer is a frequently used solution in the event of an original module failure, especially when maintaining the vehicle's factory specifications is a priority. This type of component allows for reduced repair costs compared to purchasing a new unit, while retaining the original design and control logic. A used unit can be particularly useful in situations where:

• the existing module has suffered electronic or thermal damage,
• the vehicle requires restoration to working order after unsuccessful software modifications,
• it is necessary to replace the unit with one compatible with a specific engine and transmission configuration. Before installation, it is recommended to work with a specialized service center that will perform coding, potential immobilizer matching, and functional tests in the vehicle.

Benefits of using an original BMW module

Using an original DME unit in a BMW E87 120i provides a range of practical benefits. The module is designed specifically for the N46 engine, ensuring it retains factory control maps and engine performance characteristics. This is important both from the perspective of durability and predictable vehicle behavior under various operating conditions. Key advantages include:

• preservation of the original diagnostic logic, facilitating vehicle maintenance,
• consistency with other electronic modules, which reduces the risk of software conflicts,
• continued support and update capability using standard service tools dedicated to the brand.

More information about used electronics and parts from this group

If you want to better understand when choosing a used engine control unit is justified and how to safely select a module for a specific car, it is worth checking out some practical tips. An extended discussion on the topic can be found in the article: The second life of electronics – when is it worth choosing used engine ECUs, comfort modules, and parking sensors? If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other components from the same group, such as controllers, engine management modules, or electronic systems monitoring operating parameters, check out the available parts in the BMW electronic control modules and ECUs category.