Airbag control unit with part number FK72-14D374-AH

What is the function of the airbag control unit FK72-14D374-AH?

The airbag control unit with part number FK72-14D374-AH is an OEM component manufactured by Bosch, serving as the central control unit for the passive safety system in Land Rover Discovery models. It processes data from acceleration and crash sensors and determines whether and when airbags and seatbelt pretensioners should be deployed.

As the brain of the restraint system, this module is responsible for monitoring all relevant components. It continuously checks the functionality of airbags, seatbelt pretensioners, and associated sensors. In the event of a crash, it analyzes incoming signals within milliseconds to ensure precise and timely activation of the safety systems, providing optimal protection for occupants.

This component is also known under alternative part numbers FK72-14D374-AK, FK72-14D374-AF, and FK72-14D374-AJ, which may vary depending on vehicle configuration and model year.

What defects occur in FK72-14D374-AH?

The most common reasons for repairing the FK72-14D374-AH control unit are stored crash data following an accident, a permanently illuminated airbag warning light due to internal faults, or a complete loss of communication with the diagnostic tool. These defects prevent the proper functioning of the safety system.

A key defect scenario involves the storage of crash data. After an accident, the control unit locks itself internally to prevent unintended re‑deployment. This lock can only be released through a targeted reset using specialized tools; simple clearing of fault codes via the OBD interface is not sufficient in such cases.

Another frequent issue is an internal fault, indicated by a continuously lit airbag warning light. The system detects an irreparable error within the control unit itself and switches to a safe mode, disabling the airbags.

Communication failures also represent a serious defect. The control unit no longer responds to requests from diagnostic equipment, making fault analysis or maintenance impossible. The root cause lies in the module’s internal electronics.

Depending on the vehicle configuration, various software versions are associated with this hardware, including 0285012991, 0285013127, 0285013069, and 0285013667.

How do you recognize a defect in the FK72-14D374-AH control unit?

The primary symptom of a defect in the FK72-14D374-AH control unit is a persistently illuminated airbag warning light on the instrument cluster. Additionally, diagnostic tools may fail to establish communication with the module, preventing further fault diagnosis within the system.

The airbag warning light is the clearest indicator. It does not extinguish after starting the vehicle, signaling to the driver that the restraint system is not operational. In the event of a crash, the protective function is no longer guaranteed.

Another clear sign is a loss of communication. When a professional workshop attempts to read the fault memory, the diagnostic tool receives no response from the airbag control unit, pointing to a severe internal malfunction.

In some cases, specific fault codes are stored in the fault memory, directly indicating an internal defect in the control unit, such as “control unit defective” or “internal error.”

In which vehicles is the FK72-14D374-AH control unit installed?

The Bosch airbag control unit with part number FK72-14D374-AH and its variants is specifically used in various generations of the Land Rover Discovery, covering both the second and fourth series of this off-road vehicle.

At Airbag24, we repair this control unit for the following Land Rover models:

Land Rover Discovery 2 (model years 1998–2002) and Discovery 2 Facelift (2002–2004)

Land Rover Discovery 4 (model years 2009–2013) and Discovery 4 Facelift (2013–2017)

How is the FK72-14D374-AH control unit professionally repaired?

At Airbag24, the repair process for the FK72-14D374-AH control unit follows a standardized procedure. This includes analysis, elimination of the root cause—such as resetting crash data—and final coding tailored to the target vehicle. You receive 2 years' statutory liability for defects on the completed repair.

After the removed control unit arrives at Airbag24, our technicians perform a thorough incoming inspection. They establish communication with the device and read out the fault memory to identify the exact cause of the issue.

The actual repair focuses on the defects mentioned. Stored crash data is erased through a professional module reset. During this process, the unit is disconnected from the donor vehicle using specialized tools and prepared for installation in the recipient vehicle.

A crucial step is the subsequent coding for the recipient vehicle. This ensures that the control unit correctly recognizes the vehicle’s specific equipment and properly controls all components of the safety system. This step is essential for full functionality.

Finally, a functional test is performed to confirm that the control unit is operating flawlessly and communicating without restriction. Only after a successful inspection is the unit approved for return shipment.