Airbag control unit with part number 28556-3BJ0A

What does the airbag control unit 28556-3BJ0A do?

The airbag control unit 28556-3BJ0A controls the restraint system (SRS) at Nissan. It evaluates the crash sensors, determines in an accident within milliseconds which airbags and seatbelt pretensioners trigger, and monitors the system continuously. It indicates faults via the airbag warning light, and after an accident it stores crash data and locks itself.

The monitoring covers sensors, seatbelt pretensioners, airbags and the wiring. Every irregularity is stored by the unit in the fault memory.

Why does the control unit 28556-3BJ0A fail?

Crash data from an earlier accident are the most common cause, even if no airbag has fired. A normal diagnostic tool cannot erase them. Other causes include aging electronic components, cold solder joints, moisture and corrosion as well as voltage spikes.

The crash data remain stored in the unit until Airbag24 erases them during the repair.

Aged components, cold solder joints and corrosion at plug connections affect the electronics directly. Voltage spikes arise, for example, from a weak battery or a jump-start.

Moisture can enter the housing through the connections and attack the contacts there.

How can you tell that the 28556-3BJ0A is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently, and a fault message appears in the instrument cluster. The diagnostic tool cannot reach the control unit, and the fault memory cannot be erased. As a result the airbags and seatbelt pretensioners may not be able to trigger in an emergency.

If the light shows the fault, have the system checked promptly. The signs usually occur together in practice, so a single feature is already a hint.

Which vehicles is the 28556-3BJ0A fitted in?

The airbag control unit 28556-3BJ0A from Nissan is fitted in these vehicles: Nissan Almera N17 (2011-2020). You clarify the assignment to your car via the model.

The vehicles at a glance:

• Nissan Almera N17 (2011-2020)

Comparing the part number on the label with this page only ensures that the unit is the right one. It does nothing more. So have the fault memory read out beforehand, because it shows whether the control unit is the cause or whether a plug or cable is the problem.

For the same vehicles, we also repair control units with the part numbers 28556-9KN1B, 98820-9KA0A.

How does the repair of the 28556-3BJ0A work?

First have the fault memory read out and attach the log, then disconnect the battery. Afterwards remove the control unit and create a repair order online. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, replaces defective components, erases stored crash data and carries out a function test. Afterwards your own unit comes back to you. The 3–4 working days apply only to this work at Airbag24.

Our repairs come with 2 years' statutory liability for defects. The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

How does the control unit 28556-3BJ0A get to Airbag24?

You send the control unit as a parcel or book a UPS collection for an extra charge. After the repair UPS brings the unit back to you from Airbag24.

Pack the printed repair order into the parcel, and the unit must be packed shock-proof.