Airbag control unit with part number 28556-3AH0A

What does the airbag control unit 28556-3AH0A do?

The 28556-3AH0A is the airbag control unit for Nissan vehicles in the restraint system (SRS). From the crash sensors, it calculates whether airbags and seatbelt pretensioners trigger in a crash, and monitors the function continuously. Reported faults appear on the airbag warning light.

The calculation must be done within milliseconds, which is why the electronics are active constantly.

After a crash, the unit stores crash data and locks itself.

Why does the control unit 28556-3AH0A fail?

Stored crash data comes first, even if no airbag has deployed; a standard diagnostic tool cannot erase it. Aged components, cold solder joints, moisture, corrosion and voltage spikes are also possible causes.

Crash data arises because the unit records the event. Airbag24 erases it during the repair, so you do not have to do anything about it.

Components age, connections corrode, and voltages can cause damage. Which cause applies in an individual case is shown only by the check on the test bench.

How can you tell that the 28556-3AH0A is defective?

A defect shows on the airbag warning light in the instrument cluster, which lights up permanently or intermittently. Other warning signs and a fault memory that cannot be erased also point to it; in an emergency, airbags and seatbelt pretensioners may then not deploy.

• airbag warning light on permanently or intermittently
• fault message in the instrument cluster
• no connection of the diagnostic tool to the control unit
• fault memory cannot be cleared

The warning light is the most unambiguous of these signs, because it appears directly in the driver's field of view.

Which vehicles is the 28556-3AH0A fitted in?

The 28556-3AH0A is fitted in these vehicles: Nissan Almera N17 (2011-2020). The information rests on this one part number.

The list of vehicles is here:

• Nissan Almera N17 (2011-2020)

Compare the part number on the label of the removed unit with this page. That only ensures that it is the right unit. Also have the fault memory read out before removal, because only the result shows whether the control unit is defective or whether a connector 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 28556-3AH0A work?

First read out the fault memory, enclose the log and disconnect the battery before you remove the control unit. Then create the repair order online and send the well-packed unit in. Airbag24 checks it, replaces defective components, erases the crash data and runs a function test, for which 3–4 working days are usually scheduled.

The sequence applies for safety reasons.

After the test, your own unit goes back 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 28556-3AH0A get to Airbag24?

You can send the 28556-3AH0A as a parcel to Airbag24 or book a UPS collection for an extra charge. After the repair, it comes back to you by UPS.

The printed repair order belongs in the parcel, and the control unit must be packed shockproof.