Airbag control unit with part number 50511357

What is the function of Airbag Control Unit 50511357?

The Airbag Control Unit 50511357 is the central safety module (SRS module) for the Alfa Romeo Brera 939 and Spider 939. It continuously monitors data from impact sensors and is responsible for precisely and millisecond‑fast activating airbags, seatbelt pretensioners, and other pyrotechnic restraint systems in the event of a crash.

As an original OEM part, it is perfectly matched to the vehicle architecture of these specific models. It ensures communication between various sensors (e.g., acceleration sensors) and actuators (airbags, seatbelt pretensioners) to provide optimal occupant protection.

In addition, the unit stores system‑relevant data and fault codes that are crucial for diagnosing the entire safety system and must be read out in case of a malfunction.

What defects occur with 50511357?

Defects in control unit 50511357 typically manifest as internal errors recorded in the fault memory as code B1111 (control unit defective). Another very common cause is the storage of crash data after an accident, which locks the system and prevents further operation—even if no visible damage is present.

A typical symptom is the aforementioned “internal error.” This can result from aging electronic components or voltage spikes in the vehicle’s electrical system, causing the control unit to fail its internal self‑tests and report a permanent, non‑erasable fault.

Following a collision, even minor accidents, so‑called crash data are stored in the unit’s memory. This lockout is a manufacturer‑imposed safety measure that prohibits reuse but can be deliberately reset through professional electronic repair.

Rarer still is total failure, where communication with the diagnostic tool becomes impossible. Causes may include external factors such as moisture ingress leading to short circuits, or mechanical damage to the wiring harness. This control unit is also associated with the related part number 50507543.

How do you recognize a defect in Airbag Control Unit 50511357?

The clearest indication of a defect in control unit 50511357 is the permanently illuminated red airbag warning light (SRS lamp) on the instrument cluster. Often, the fault memory cannot be cleared, or the control unit is completely unreachable via diagnostic tools—signs of a severe internal fault.

The persistently lit airbag warning light is the primary symptom. It does not extinguish after starting the vehicle, signaling to the driver that the entire restraint system is inactive and would not deploy in a crash.

During workshop diagnostics, the specific fault code B1111 (“control unit defective”) is frequently retrieved. This code directly points to an irreparable internal fault within the module itself, requiring either replacement or specialized repair.

Another clear symptom is the lack of communication. If a workshop attempts to read the control unit via the OBD interface, no response is received, blocking any further diagnosis of the airbag system.

In which vehicles is control unit 50511357 installed?

The airbag control unit with part number 50511357 is specifically designed for certain Alfa Romeo models. It is primarily used in the 939 series, encompassing both the Brera and the Spider, including their respective facelift versions.

At Airbag24, we offer expert repair services for control unit 50511357 for the following Alfa Romeo models:

Alfa Romeo Brera: 939 (model years 2006–2008) and 939 Facelift (model years 2008–2010)

Alfa Romeo Spider: 939 (model years 2007–2008) and 939 Facelift (model years 2008–2010)

Is repairing 50511357 worthwhile?

Repairing the Airbag Control Unit 50511357 offers significant advantages over purchasing a new unit. The most decisive factor is substantial cost savings. Additionally, the original vehicle coding is preserved, eliminating the need for time‑consuming reprogramming at the workshop and allowing immediate use of the repaired unit.

A new part can cost over €400, plus programming and coding fees at a specialist workshop. Repair is a far more economical solution without compromising safety or functionality.

Another key benefit is maintaining the original coding. The repaired control unit is precisely tailored to your vehicle and requires no additional programming or retraining after installation, saving time and extra workshop expenses.

Professional repair, including the erasure of crash data, is a sustainable and proven method to restore the full functionality of your airbag system. With 2 years’ statutory liability for defects on all work performed, this repair offers a safe and reliable alternative.

How does the repair of part number 50511357 at Airbag24 proceed?

The repair of control unit 50511357 at Airbag24 is a standardized process that begins with the submission of the removed unit. Following a thorough incoming inspection, defects at the chip level are fixed, crash data is erased, and the device is restored to its factory settings before being tested and returned to you.

The process ideally starts with reading out the vehicle’s fault memory to confirm the diagnosis. Subsequently, the control unit—typically mounted beneath the center console—is professionally disassembled and securely packaged for shipment to Airbag24.

Upon receipt, our technicians conduct a comprehensive analysis to pinpoint the exact cause of the fault. This includes inspecting the circuit board for defective components and reading the internal memory.

The actual repair involves replacing faulty electronic parts and professionally erasing the stored crash data. Using specialized programming tools, the control unit is fully reset, ensuring it regains full operational capability.

Finally, the repaired unit undergoes a functional test. Since the original vehicle coding is preserved, the control unit is ready for immediate installation after reassembly. We provide 2 years' statutory liability for defects on every repair.