Airbag control unit with part number 28556 6F707

What is the function of Airbag Control Unit 28556 6F707?

The airbag control unit with part number 28556 6F707 is the central control module for the occupant restraint system (SRS) in the Nissan Micra K11. It processes signals from crash sensors to precisely deploy airbags and seatbelt pretensioners in the event of a collision. Its primary role is to ensure passive safety for vehicle occupants.

Technically, the unit continuously monitors all components of the airbag system—from sensors and wiring to the airbag igniters. If a fault occurs, the airbag warning light on the instrument panel illuminates to alert the driver.

In the Nissan Micra K11, this control unit is typically installed behind the center console. From there, it coordinates the entire passive restraint system and stores system-relevant data, including fault codes and, in the event of a crash, irreversible crash data.

Why does control unit 28556 6F707 fail?

The most common cause of failure for control unit 28556 6F707 is the storage of crash data after an accident. Other defects arise from internal electronic faults—such as those triggering error code B1059—or from peripheral issues like faulty wiring or loose connectors.

Following a crash, the unit stores crash data in its internal memory. This lockout feature is intentionally designed by the manufacturer to prevent reuse without professional inspection and reset. The system then reports a permanent fault that cannot be cleared using standard diagnostic tools.

A specific internal defect unique to Nissan is error code B1059, which indicates an irreparable internal hardware or memory fault requiring professional component-level repair. Often, memory chips (EEPROMs) or other circuit board components are affected.

Although less frequent, external factors such as broken wires, corrosion at connector contacts, or voltage fluctuations in the vehicle’s electrical system can also lead to malfunctions or total failure of the control unit.

Several equivalent part numbers are known for this module, which has also been used in the Nissan Micra K11. These include: 9858445B03, 28556AP002, 285001183, and 285001411, as well as the Bosch‑compatible module 0285001411.

How do you recognize a defect in 28556 6F707?

The clearest symptom of a defect in control unit 28556 6F707 is a permanently illuminated or intermittently flashing airbag warning light on the instrument panel. Frequently, the control unit can no longer be accessed via OBD2, or persistent error codes appear that cannot be cleared.

The constantly lit airbag indicator light is the primary warning sign, indicating that the system has detected a serious malfunction and is not functioning properly in an emergency. Ignoring this warning poses a significant safety risk.

Another clear indication is when a workshop using a diagnostic tool cannot establish communication with the airbag control unit. The unit fails to respond to queries, suggesting a complete failure of its internal electronics.

In other cases, communication may still be possible, but error codes such as B1059 (internal fault) remain stored and cannot be reset using standard methods. This behavior is typical after a crash or following an internal component failure.

In which vehicles is control unit 28556 6F707 installed?

The airbag control unit with part number 28556 6F707 was specifically developed for the second generation of the Nissan Micra. It is found across all variants of the K11 series, including both facelift models produced up to 2003.

At Airbag24, we repair part number 28556 6F707 for the following Nissan Micra K11 models:

Nissan Micra K11 (model years 1992–1998)

Nissan Micra K11 First Facelift (model years 1998–2000)

Nissan Micra K11 Second Facelift (model years 2000–2003)

How is control unit 28556 6F707 professionally repaired?

A professional repair of control unit 28556 6F707 involves erasing stored crash data, reprogramming internal memory chips, and thoroughly inspecting and restoring the hardware. The goal is to restore the original device’s full functionality.

After removal from the vehicle, the control unit is sent to us. At Airbag24, it undergoes a standardized repair process that begins with a comprehensive incoming inspection to pinpoint the exact cause of the fault.

Subsequently, crash data or internal errors such as B1059 are eliminated through direct reprogramming of the memory chips. If hardware defects exist on the circuit board, at solder joints, or in other components, these are expertly repaired.

After successful repair, the control unit is tested on a test bench to simulate the correct functioning of all system components. The key advantage: the repaired original part is immediately ready for installation and does not require re-coding in the vehicle. We provide 2 years' statutory liability for defects on every repair.