Airbag control unit with part number 285A49105R

What is the function of the airbag control unit 285A49105R?

The airbag control unit with part number 285A49105R is the central control unit for the entire passive safety system in the Renault Arkana I. It analyzes data from impact sensors, deploys airbags and seatbelt pretensioners in the event of a collision, and permanently stores all relevant crash data.

Technically designated as an SRS ECU (Supplemental Restraint System - Electronic Control Unit), this component is responsible for monitoring and ensuring the operational readiness of all safety‑related components. It is typically located in the vehicle’s center console, right next to the gearshift lever, to provide optimal protection from external influences.

Its primary task is to make lightning‑fast decisions about which restraint systems need to be activated during a crash. After deployment, the unit locks out system functions and signals a permanent fault until the crash data has been professionally reset. The internal Bosch reference number may be 0 285 020 584.

Why does the control unit 285A49105R fail?

The most common cause of failure for the control unit 285A49105R is the storage of crash data after an accident. This data irreversibly blocks the system and generates persistent error codes, even if the airbags did not deploy. Simple clearing via standard diagnostic tools is not possible in such cases.

Following an impact, a so‑called “crash lock” is set in the control unit’s memory. This condition is intentionally programmed by the manufacturer to force a full system check. Even used control units sourced from donor vehicles almost always exhibit this crash‑data lock and cannot be reused without specialized repair.

It is crucial to verify the exact part number. Similar numbers like 285A44164R or 285A40674R are intended for other engine types or trim levels of the Renault Arkana and are not directly interchangeable. Even minor differences in the index letters can significantly affect compatibility.

How do you recognize a defect in the 285A49105R?

A defect in the control unit 285A49105R primarily manifests as a continuously illuminated airbag warning light on the instrument cluster. Additionally, specific error codes indicating “crash data stored” or an “internal fault” of the control unit are logged in the vehicle’s fault memory.

The vehicle reports a failure of the restraint system, and the warning light remains on even after restarting the engine. This is a clear indication that the airbag system is no longer functional and would not deploy in another accident.

During diagnostics via the OBD interface, error codes can be read that explicitly point to a blockage caused by stored crash data. In some cases, communication with the control unit may be completely disrupted, further complicating fault analysis.

In which vehicles is the control unit 285A49105R installed?

The airbag control unit 285A49105R is specifically designed for models of the Renault Arkana I. At Airbag24, we perform professional repairs on this control unit, which was predominantly fitted in first‑generation Arkana vehicles built from 2019 onward.

Its primary application is found in the following model:

Renault: Arkana I (model series LCM_, LDN_) from 2019 onwards, especially in vehicles equipped with the 1.6‑liter engine (designation LCM1), often paired with hybrid or gasoline powertrains and automatic transmissions.

Since compatibility depends on the exact part number, it is essential to verify the number printed on the original component before requesting a repair.

How does the repair of the 285A49105R proceed at Airbag24?

During professional repair of the control unit 285A49105R, the internal memory is read using specialized software, and all stored crash data is completely erased. This “crash reset” restores the module to its factory‑original state, making it fully functional again. Airbag24 offers 2 years' statutory liability for defects on this repair.

The process at Airbag24 is designed for maximum safety and efficiency. After removing the unit from the vehicle, please send the unopened control unit along with the order form to our workshop. Please note that this is a pure repair service, not a sale of replacement parts.

Our technicians conduct a precise diagnosis and reset the crash data. All relevant error codes associated with the accident are cleared. The control unit then undergoes a functional test before being securely returned to you.