Airbag control unit with part number 28556-9CA0A

What does the airbag control unit 28556-9CA0A do?

The airbag control unit 28556-9CA0A is the central control unit of the SRS in Nissan. It evaluates the measured values of the crash sensors and decides which airbags and seatbelt pretensioners are triggered, in fractions of a second.

The unit monitors the entire system constantly. If it reports a fault, this appears on the airbag warning light in the instrument cluster.

After an accident, it stores crash data and locks itself.

Why does the control unit 28556-9CA0A fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. In addition, ageing electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes, for example from a weak battery or a jump start, can disturb the unit.

A normal diagnostic tool cannot erase crash data. Anyone who tries this gets nowhere, which is why the finding belongs in a workshop.

Components age, solder joints can be cold, moisture attacks plug connections, and voltage spikes stress the electronics. Which of these causes is present in the individual case is only shown by the inspection.

How can you tell that the 28556-9CA0A is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently. In addition, a fault message appears, the diagnostic tool cannot reach the control unit and the fault memory cannot be cleared.

In this condition, airbags and seatbelt pretensioners may not deploy in an emergency. The light is therefore not a sign of a minor issue, but an indication of a disturbed system.

Which vehicles is the 28556-9CA0A fitted in?

The control unit 28556-9CA0A is fitted in these vehicles: Nissan Xterra N50 (2005-2008) and N50 Facelift (2008-2015). The list relates to this part number and to the make Nissan.

The following vehicles are concerned:

• Nissan Xterra N50 (2005-2008)
• Nissan Xterra N50 Facelift (2008-2015)

Check the part number on the label of the removed unit against this page. That only ensures it is the correct unit. Before you remove the control unit, have the fault memory read out, because only this result shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 28556-EC00B, 98820-AV200, 98820-AV21A, 98820-ZP31A.

How does the repair of the 28556-9CA0A work?

First have the fault memory read out and attach the log. Then disconnect the battery and only afterwards remove the control unit. You create a repair order online and send the unit off well packed; Airbag24 checks it, replaces defective components, erases the crash data and carries out a function test.

Processing at Airbag24 usually takes 3–4 working days. The 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 28556-9CA0A get to Airbag24?

The unit is sent in as a parcel, or UPS collects it from you for an extra charge. Airbag24 sends the repaired unit back by UPS.

The printed repair order belongs in the parcel. Pack the control unit shock-resistant.