Airbag control unit with part number 46449690

What is the function of Airbag Control Unit 46449690?

The airbag control unit with part number 46449690 is the central control module of the Occupant Restraint System (SRS) in the Alfa Romeo 156. It processes data from crash sensors and, within milliseconds, determines whether to deploy airbags and seatbelt pretensioners to protect occupants in the event of a collision.

As the brain of the safety system, this SRS ECU (Supplementary Restraint System Electronic Control Unit) continuously monitors all connected components, including front and side airbags, seatbelt pretensioners, and various acceleration and seat‑occupancy sensors. Any irregularity in the system is detected and recorded as a fault code.

The proper functioning of this control unit is critical for the vehicle’s passive safety. A failure or malfunction will inevitably disable the entire airbag system, which can have fatal consequences in the event of an accident.

Why does control unit 46449690 fail?

The most common causes of failure for control unit 46449690 are internal electronic malfunctions, stored crash data after an accident, or communication errors. Often, an internal component failure results in total system failure, indicated by fault code B1111 (control unit defective).

A widespread issue is internal hardware failure. Electronic components such as processors or memory chips on the circuit board may fail due to aging or thermal stress, rendering the control unit unresponsive and unable to communicate with diagnostic equipment.

After an accident or unintended deployment—such as a severe impact to the underbody—the unit stores crash data. This data retention serves as a safety measure, permanently locking the control unit out of service. Professional repair can remove this lock by securely erasing the crash data.

In some cases, external factors like corrosion at connector contacts—especially those beneath the front seats—are also to blame. Therefore, it’s advisable to inspect these connections before removing the control unit. Used replacement parts, such as part number 60663943, are available but often require vehicle‑specific coding and carry the risk of unknown pre‑existing damage.

How do you recognize a defect in Airbag Control Unit 46449690?

The clearest symptom of a defect in control unit 46449690 is the persistently illuminated airbag or SRS warning light on the instrument cluster. Frequently, the control unit cannot be read by diagnostic equipment, or it reports an internal, non‑erasable fault such as B1111.

The airbag warning light fails to extinguish after starting the vehicle or begins flashing, signaling to the driver that the entire restraint system is disabled and will not function in the event of a crash.

Another clear indication is the lack of communication: the workshop cannot establish a connection to the airbag control unit via the OBD interface to read the fault memory. The unit simply no longer responds to diagnostic requests.

In some cases, the defect may also appear alongside other warning lights, such as the engine check light, pointing to a deeper electronic issue within the vehicle—often originating in the airbag control unit.

In which vehicles is control unit 46449690 installed?

The airbag control unit with part number 46449690 was specifically developed for the Alfa Romeo 156 series (932). It was used across all production years—including facelift models and the sporty GTA—in both sedan and station wagon variants.

At Airbag24, we repair part number 46449690 for the following Alfa Romeo models:

Alfa Romeo 156 (Series 932, 1997–2004)

Alfa Romeo 156 Facelift (Series 932, 2002–2007)

Alfa Romeo 156 GTA (Series 932)

What are the benefits of repairing 46449690?

Repairing the original control unit is the most cost‑effective and technically reliable solution. Compared to a new part, which can cost around €400, repairs save significantly and avoid compatibility issues or the need for expensive re‑coding with the vehicle manufacturer.

A key advantage is the substantial cost savings—often exceeding 70% compared to purchasing a new unit. While repairs remain competitively priced, they also restore full system functionality.

Since your original control unit is repaired, all vehicle‑specific data remains intact. After repair, the unit can be easily reinstalled (plug-and-play) without requiring time‑consuming programming or re‑learning procedures for the vehicle. This is a significant benefit over using used replacement parts.

Additionally, you receive 2 years’ statutory liability for defects on the completed repair, providing you with extra peace of mind. You’re investing in a sustainable solution that restores the original system safety as intended by the manufacturer.

How does the repair process work at Airbag24?

The repair process at Airbag24 is simple and transparent. After removal, you send us your defective control unit. Our technicians perform a precise analysis, fix the fault at the component level, and reset any stored crash data. The unit is then tested and returned to you.

Beforehand, it’s advisable to have a diagnosis performed at a specialized workshop to confirm that the issue lies with the control unit itself and not with the wiring or sensors. In the Alfa Romeo 156, the control unit is typically located beneath the center console, near the ashtray.

Upon receipt at Airbag24, professional refurbishment takes place. Defective electronic components are replaced with new, high-quality parts, and solder joints are reworked. For units with stored crash data, the memory is professionally cleared to restore full functionality.

Following successful repair and final testing, the control unit is shipped back to you. After reinstalling it in your vehicle, you only need to clear the vehicle’s fault memory to reactivate the system. We provide 2 years' statutory liability for defects on every repair.