Airbag control unit with part number 28556-3AJ0B

What does the airbag control unit 28556-3AJ0B do?

The airbag control unit 28556-3AJ0B forms the central control unit of the restraint system in vehicles from Nissan. It evaluates the signals from the crash sensors, decides within milliseconds in the event of an accident which airbags and seatbelt pretensioners to trigger, and monitors the system continuously.

If the unit detects a fault in the system, it reports this via the airbag warning light in the instrument cluster. Monitoring runs constantly in the background so that the control unit can react without delay in an emergency.

After an accident, the unit stores crash data and locks itself. The lock is only lifted by the repair.

Why does the control unit 28556-3AJ0B fail?

The most common cause in the 28556-3AJ0B is a crash data record stored after an accident, even if no airbag has deployed.

A normal diagnostic tool cannot erase this data. Other causes include aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

The fact that no airbag has deployed does not mean the unit has not stored crash data. The other causes are general in nature: electronics age, solder joints can go cold, and moisture attacks plug connections.

Voltage spikes occur, for example, with a weak battery or when starting the engine with an external power source. Airbag24 erases the stored crash data during the repair.

How can you tell that the 28556-3AJ0B is defective?

On the 28556-3AJ0B, the airbag warning light in the instrument cluster lights up permanently or intermittently. In addition, a fault message appears in the instrument cluster, the diagnostic tool has no connection to the control unit, and the fault memory cannot be cleared. Airbags and seatbelt pretensioners may then possibly not trigger in an emergency.

Take this warning seriously even if the vehicle continues to drive. A prompt inspection is then the right step.

Which component is affected is only revealed by reading out the fault memory. The light alone does not show whether the control unit itself or a wire behind it is the cause.

Which vehicles is the 28556-3AJ0B fitted in?

The 28556-3AJ0B is fitted in these vehicles: Nissan Almera N17 (2011-2020).

The following vehicles are recorded for this part number:

• Nissan Almera N17 (2011-2020)

Compare the part number on the label of the removed unit with this page. This only ensures that you have the right unit in front of you. Before removal, also have the fault memory read out, because only that result shows whether the control unit is defective or a plug or cable is the cause.

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

How does the repair of the 28556-3AJ0B work?

First, have the fault memory read out and enclose the log. Then disconnect the battery and only afterwards remove the control unit 28556-3AJ0B. Next, create a repair order online and send the unit in well packed.

Airbag24 then examines the unit on the test bench, repairs defective components, erases the stored crash data and carries out a function test. Processing usually takes 3–4 working days. Afterwards, your own unit is returned to you.

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 28556-3AJ0B get to Airbag24?

You send the control unit 28556-3AJ0B to Airbag24 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

Place the printed repair order in the parcel. Pack the unit shock-proof so that it arrives at Airbag24 undamaged.