Audi A3 8V ECU Kit Ignition Switch Key 1.4 TFSI 122HP CMBA Automatic 04E907309A

Audi A3 8V ECU Kit Ignition Switch Key 1.4 TFSI 122HP CMBA Automatic is a set from the Electronic control modules and controllers group, designed for Audi vehicles with a 1.4 TFSI engine and an automatic transmission. The kit ensures consistent operation of the ignition system, engine control, and key authorization, facilitating professional repair or replacement of a damaged module in the car.

Specifications and technical data

• SKU: 04E907309A-5
• Mark: Audi
• Condition: Used
• OEM Part Number: 04E907309A
• Substitutable numbers: 04E907309A, 04E 907 309 A, 0261S07726, 0 261 S07 726, 5Q0937084N, 5Q0 937 084 N, 5WK50591, 5Q0 937 084 CF, 5Q0937084CF, 5Q0905865, 5Q0 905 865, 8V0837220D, 8V0 837 220 D
• Gearbox type: Automatic
• Part type: Engine Control Unit (ECU)
• Category: ECUs & Computer Modules

Purpose and function of the kit

The presented set includes an ECU, an ignition switch, and a key, matched in terms of software and coding. In practice, this means that after proper installation and adaptation in the vehicle, it is possible to restore the correct operation of the ignition system, communication with the immobilizer, and cooperation with other electronic modules in an Audi A3 8V with a 1.4 TFSI CMBA unit and an automatic transmission. A set configured in this way is particularly useful in situations where there has been damage to the controller, problems with key recognition, or improper operation of the ignition switch following a collision, water damage, or electrical system faults.

Benefits of using a complete module

Using a complete ECU–ignition switch–key set allows for reduced diagnostic and programming time, as the components are already synchronized. For workshops and service centers, this means:

• easier matching to the specific configuration of an Audi A3 8V with a 1.4 TFSI CMBA engine,
• reduced risk of conflicts between the controller and the immobilizer system,
• a more predictable vehicle startup process after repair. For the end user, this translates into a more efficient restoration of the vehicle's full functionality and stable operation of the electronic systems responsible for starting and powertrain management.

Technical characteristics and vehicle integration

The set is designed to work with an automatic transmission, which is significant for powertrain control logic, communication with the transmission module, and safety systems. A properly selected ECU combined with the ignition switch and key allows for maintaining the correct operating parameters of the 1.4 TFSI engine, including ignition control, fuel dosage, and CAN bus communication with other controllers in the vehicle. Elements from this group are designed as part of an integrated Audi electronics ecosystem, which is why it is crucial to use a set with the correct application during replacement, minimizing the need for deep software modifications and reducing the risk of communication errors between modules.

Product condition and use in service practice

The offered set is used, making it an attractive cost-effective solution while maintaining factory design and performance characteristics. In workshop practice, such components are often chosen for repairing vehicles after collisions, electronic failures, or engine starting problems when repairing the existing controller is not cost-effective. Before installation, a standard diagnostic procedure and verification of the vehicle's electrical system are recommended to ensure proper operating conditions for the module and to avoid re-damage. Professional installation and appropriate adaptation in the vehicle allow for fully utilizing the potential of the set and restoring the correct operation of the ignition system.

Expanding the electronics system in an Audi

If you are planning a comprehensive repair or upgrade of the control electronics area in your Audi and need other elements from the same group, such as comfort controllers, body modules, or additional ECU units, check the available parts in the Electronic control modules and controllers Audi category. For a better understanding of how advanced electronic systems work in modern cars and how to use dismantled parts in diagnostics and repairs, it is worth reading an article describing a practical approach to control modules in premium vehicles: Driving pleasure for years – how to take care of iDrive systems and electronic modules in BMW 3 and 5 series models using dismantled parts? If you are also interested in the repair of drivetrains and suspensions in Audi using original aftermarket components, the following service guide may be helpful: Repairing Quattro drivetrains and suspensions in Audi models: why is it worth relying solely on used factory parts?