Airbag control unit with part number 315A19AB601

What is the function of the airbag control unit 315A19AB601?

The airbag control unit with part number 315A19AB601 is the central control module for the occupant restraint system (SRS) in the BMW iX3 of the G08 series. It analyzes data from acceleration and crash sensors and, within milliseconds, determines whether to deploy airbags and tighten seat belts to protect vehicle occupants in the event of a collision.

As the “brain” of the passive safety system, this module continuously communicates with all relevant components. It monitors the functionality of individual airbags, seat belt pretensioners, and associated sensors. During each vehicle initialization, it performs a self-test, the results of which are indicated by the SRS warning light on the instrument cluster.

Due to its critical safety role, the control unit is typically installed centrally and protected inside the vehicle cabin—often beneath the front seats or in the center console—to provide optimal protection against external influences.

Why does the control unit 315A19AB601 fail?

A failure of the control unit 315A19AB601 is often caused by stored crash data following an accident, which permanently locks the device. Other causes include internal electronic defects in components such as microcontrollers, electrical disturbances due to undervoltage or overvoltage, and physical damage from moisture or mechanical impact.

The most common reason for necessary repair is the storage of crash data. After an accident involving airbag deployment, the unit writes this data into a non-erasable memory area to prevent tampering. For safety reasons, the system then becomes locked and must be professionally reset.

Electronic faults are another frequent cause of failure. Internal error codes such as B1350 (internal memory error), 65535 (control unit defective), 93F9 (internal fault), or B1000 often indicate defective hardware components. Short circuits in the vehicle’s electrical system, cable breaks, or aging of components like capacitors can lead to complete system failure.

External factors, such as spilled liquids entering the housing or mechanical damage during other vehicle repairs, can also destroy the control unit’s sensitive electronics.

How do you recognize a defect in the control unit 315A19AB601?

The clearest sign of a defect is the airbag warning light (SRS light) that remains illuminated continuously or intermittently in the cockpit. Additionally, the control unit may no longer communicate with diagnostic tools or display error codes indicating an internal fault that cannot be cleared.

The red SRS warning light on the dashboard is the primary indicator for the driver that there is a problem with the restraint system. In this state, the system may be effectively disabled, posing a significant safety risk in the event of a crash.

In the workshop, a defect often manifests as a lack of diagnostic capability. Professional testers such as OBD scanners, Guzzi testers, or Bosch testers receive no response from the control unit, making it impossible to troubleshoot the vehicle.

If error codes such as B1000, 65535, or 93F9—explicitly pointing to an internal hardware fault—are read, repair is unavoidable. A missing vehicle identification number or a blocked fault memory are also clear symptoms.

Important: Driving with a lit airbag warning light is dangerous. Attempts to bypass the system using simulators or resistors are illegal and life‑threatening, as they leave occupants without protection in an emergency.

In which models is 315A19AB601 installed?

The airbag control unit with part number 315A19AB601 is specifically used in the all‑electric BMW iX3 SUV series. This includes both the original model and the revised LCI version (Life Cycle Impulse), produced starting in 2021.

At Airbag24, we repair the control unit 315A19AB601 for the following specific vehicle models:

BMW iX3 (G08 series) from model year 2021 onward

BMW iX3 LCI (G08 facelift series) from model year 2021 onward

Since the iX3 is a fully electric vehicle, its onboard electronics are subject to special requirements. Repair therefore demands specialized knowledge of high‑voltage vehicle architecture to ensure professional and safe restoration.

How does the repair of 315A19AB601 proceed at Airbag24?

The repair process at Airbag24 begins with the proper removal of the control unit and its shipment along with a diagnostic report. Following a detailed incoming inspection, electronic refurbishment takes place, during which crash data is erased or defective components replaced, depending on the nature of the fault. Finally, the unit is tested and prepared for shipment.

First, a diagnosis should be performed on the vehicle at a specialized workshop, and the fault log should be documented. Next, the airbag control unit is removed and securely packaged for shipment to us.

Upon receipt at Airbag24, our technicians conduct a thorough analysis. The unit is connected to specialized test benches to verify the reported fault and identify any additional potential issues.

The actual repair is carried out at the component level. This includes professionally erasing crash data, replacing defective microcontrollers, capacitors, or other electronic components through precise soldering, as well as restoring the original software and performing necessary coding.

After successful repair, the control unit undergoes a final functional test. Once it has passed all tests, it is prepared for return shipment. We provide 2 years' statutory liability for defects on every repair. Following reinstallation in the vehicle, the vehicle’s overall fault memory may need to be cleared.