Audi A4 B9 A5 F5 30 TDI DTNB 136HP Engine Control Unit ECU 05L907309 Automatic

Audi A4 B9 A5 F5 30 TDI DTNB 136HP Engine Control Unit ECU is a specialized electronic controller designed for diesel units paired with an automatic transmission. This component from the Electronic control modules and controllers category is responsible for precise engine management, ensuring stable performance and proper integration with the drivetrain. Thanks to its factory design, the ECU is perfectly matched to the electrical architecture of Audi A4 B9 and A5 F5 models with the 30 TDI engine.

Specifications and technical data

• SKU: 05L907309
• Mark: Audi
• Condition: Used
• OEM Part Number: 05L907309
• Substitutable numbers: 05L907309, 05L 907 309, 0281034002, 0 281 034 002
• Fuel type: Diesel
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and function of the engine control unit

The presented engine control unit is designed to support the 30 TDI diesel engine with 136 HP, marked with the DTNB code. The controller is responsible for managing fuel injection, turbocharging, combustion parameters, and communication with the automatic transmission, which translates into smooth acceleration and predictable throttle response. Using a dedicated ECU ensures compliance with factory control maps and the operating logic of auxiliary systems.

Drivetrain compatibility

This engine control unit is intended for Audi vehicles equipped with an automatic transmission, where strict synchronization between the engine and the transmission control module is required. This allows for maintaining optimal RPM during gear shifts, reducing jerking, and ensuring the correct operation of comfort functions, such as drive modes or adaptive gear-shifting strategies. The controller works with the diesel fuel system, taking into account the specific operation of the diesel engine, including fuel rail pressure control and support for emission reduction systems.

Benefits of using an original ECU

Using an original engine control unit in an Audi A4 B9 or A5 F5 allows for maintaining software consistency with other vehicle modules, such as safety, comfort, and drivetrain systems. This solution reduces the risk of communication errors on the data bus and facilitates diagnostics using factory service tools. For the user, this means more predictable vehicle behavior, stable engine operation, and the ability to continue service maintenance in accordance with the manufacturer's standards.

Application in service practice

This type of engine control unit is often used for repairs following electrical damage, water ingress, or internal ECU failure. Replacing it with the correct model matched to the 30 TDI engine and automatic transmission restores full vehicle functionality without the need for modifications to the electrical installation. In workshop practice, the ability to match software to a specific vehicle configuration is important, which is why choosing a controller from the same design family simplifies the adaptation and coding process.

If you are planning a comprehensive repair or upgrade of the engine area in your Audi and need other components from the same group, such as engine controllers, engine management modules, or electronic parameter control systems, check the available parts in the Audi electronic control modules and controllers category.

How to consciously choose a used engine control unit

When selecting a used ECU for an Audi A4 B9 or A5 F5, it is crucial to match it to the fuel type, engine version, and transmission type. It is worth paying attention to compatibility with the vehicle's electrical architecture and the possibility of adaptation at a chosen service center. It is also good practice to verify the module's origin history and perform diagnostics after installation to confirm proper communication with all vehicle systems.

To better understand when choosing a used controller is cost-effective and what to look out for during installation and coding, check out our guide: The second life of electronics – when is it worth choosing used engine controllers, comfort modules, and parking sensors?