Airbag control unit with part number 28556-3HW0A

What does the airbag control unit 28556-3HW0A do?

The airbag control unit 28556-3HW0A is the central control unit of the restraint system for Nissan. It measures what happens in an accident via the crash sensors, decides on airbags and seatbelt pretensioners, and monitors the system continuously.

The unit detects faults in the system and reports them via the airbag warning light in the instrument cluster.

After an accident it stores crash data and then locks itself. The lock is part of the system's design.

Why does the control unit 28556-3HW0A fail?

If crash data is stored on the 28556-3HW0A, that is the most common cause, even when no airbag has triggered. Other possible causes are aged electronic components, cold solder joints, moisture and corrosion, and voltage spikes.

Crash data cannot be erased with a normal diagnostic tool. It therefore stays in the unit, regardless of whether the airbags have triggered.

The remaining causes affect the electronics and their connections. Moisture affects the connectors, and voltage spikes arise, for example, from a jump-start.

How can you tell that the 28556-3HW0A is defective?

On the 28556-3HW0A, a fault shows itself through the airbag warning light in the instrument cluster, which lights up permanently or intermittently, and through a fault message in the instrument cluster.

Further signs are:

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

In an emergency, airbags and seatbelt pretensioners may then fail to trigger. Therefore, have the findings checked.

Which vehicles is the 28556-3HW0A fitted in?

The control unit 28556-3HW0A is fitted in these vehicles: Nissan Altima L33 (2012-2018).

You will find the matching models in the following list.

• Nissan Altima L33 (2012-2018)

Compare the part number on the label of the removed unit with this page. This only shows that it is the right unit. Whether the control unit itself is defective, or a connector or cable is behind the fault, is established only by the read-out fault memory.

For the same vehicles, we also repair control units with the part numbers 98820-3TA0B, 98820-3TA9C, 98820-9HN0A, 98820-9HS9A.

How does the repair of the 28556-3HW0A work?

On the 28556-3HW0A, have the fault memory read out and enclose the log. After disconnecting the battery, remove the control unit. Airbag24 needs 3–4 working days as a rule for testing, repairing and checking.

Then create the repair order online and send the unit in well packed. Airbag24 inspects it on the test bench, replaces defective components, erases the crash data and carries out a function test.

Your own unit is then 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 28556-3HW0A get to Airbag24?

You send the control unit 28556-3HW0A in as a parcel or book a UPS collection for an extra charge. Returns after the repair are made by UPS.

Put the printed repair order into the parcel, and pack the unit shock-proof.