B1107 airbag control unit fault

What does error code B1107 mean in the airbag control unit?

Error code B1107 indicates a serious issue with the configuration of the airbag control unit. Typically, the cause is an incorrect, incompatible, or faulty label file responsible for properly configuring the device. This prevents the control unit from performing its safety functions, resulting in the deactivation of the airbag system.

From an electronic standpoint, the label file serves as a kind of operating manual, informing the control unit which airbags, seatbelt pretensioners, and sensors are installed in the vehicle and how they should respond. If this file is damaged or does not match the hardware of the control unit, the system cannot be initialized correctly.

Although the root cause often lies in software configuration, underlying hardware defects can also trigger this error. Internal faults, short circuits, or damage caused by water ingress may compromise the memory areas where configuration data is stored.

Typical symptoms of error code B1107

The primary and unmistakable symptom of error B1107 is the permanently illuminated airbag warning light on the instrument cluster. This light does not turn off after starting the vehicle. Additionally, during diagnostics, the control unit may become unresponsive or respond only incorrectly.

The active airbag warning light is a critical safety signal. It indicates that the entire restraint system is disabled, meaning neither airbags nor seatbelt pretensioners would deploy in the event of a crash.

Another sign may be faulty communication with diagnostic tools. When attempting to read the fault memory using professional testers such as those from Bosch or Gutmann, connection interruptions may occur, or the device may directly report configuration error B1107.

Possible causes of error code B1107

The main cause of B1107 is an incorrect configuration or a defective label file within the airbag control unit. This can result from installing an incorrect, incompatible control unit or from unsuccessful programming attempts. Less frequently, internal hardware defects—such as short circuits or water damage—can also trigger the error.

A common cause is installing an incorrect or used control unit that has not been programmed for the specific vehicle model or trim level. Each control unit is tailored to the vehicle’s identification number and the installed sensor technology.

A damaged or faulty label file represents a problem at the software or parameterization level. This can be caused by voltage spikes or improper write operations in the device’s memory.

In some cases, there is a hardware defect on the control unit’s circuit board. Defective components, cold solder joints, or corrosion following water damage can disrupt the processing of configuration data, thereby triggering error B1107.

In diagnostic practice, alongside B1107, other error codes may appear, indicating issues with power supply or internal defects. These include B1101 and B1102 (SRS control unit battery voltage too high/too low), as well as B1111 (control unit defective).

Which vehicles experience error B1107?

While error code B1107 is not limited to any single brand, it occurs specifically in certain models. At Airbag24, we have successfully diagnosed and repaired this error code in models such as the Bentley Eight Mk1 and the Toyota Supra A90 from 2019 onward.

At Airbag24, we repair airbag control units exhibiting error B1107 for the following vehicles:

Bentley: Particularly in the classic Bentley Eight Mk1, this configuration error can occur.

Toyota: The error is also known in the newer generation of the Toyota Supra (A90, from 2019 onwards).

How is error B1107 repaired?

A professional repair of error B1107 involves a thorough analysis at both the hardware and software levels. At Airbag24, upon receipt, the control unit is inspected, defective components are replaced, and the configuration along with the label file is expertly restored. You receive a 2-year warranty on the completed repair.

After sending the removed airbag control unit to Airbag24, the repair process begins with a comprehensive diagnosis. First, the fault memory is read to confirm error B1107 and identify any additional errors.

Next, the hardware is examined for visible damage such as short circuits or water damage. Simultaneously, the software—especially the label file and the control unit’s configuration—is analyzed to pinpoint the exact cause of the malfunction.

The actual repair involves, depending on the findings, replacing defective electronic components such as capacitors, resistors, or integrated circuits (ICs). Subsequently, the correct label file is reprogrammed, or the control unit’s firmware is updated to the appropriate version.

Following the restoration, the control unit undergoes a comprehensive functional test. Only after passing this test is it returned. After reinstalling it in the vehicle, the fault memory must be cleared. Airbag24 provides a 2-year warranty on this repair.

Attention: Work on the airbag system may only be performed by trained specialists. The use of simulators or bypass resistors is life‑threatening and will result in the loss of the vehicle’s operating permit.