Airbag control unit with part number 28556-4KJ0C

What does the airbag control unit 28556-4KJ0C do?

For Nissan, the airbag control unit 28556-4KJ0C is the central control unit of the restraint system (SRS). It evaluates the messages from the crash sensors, determines within milliseconds in a collision whether airbags and seatbelt pretensioners are triggered, and checks the system continuously. If it detects a fault, it shows it via the airbag warning light.

The evaluation happens faster than a person could react, and without you having to do anything yourself.

After an accident it stores crash data and locks itself.

Why does the control unit 28556-4KJ0C fail?

The most common cause is stored crash data from an accident, even if no airbag has fired; this data cannot be cleared with a normal diagnostic tool. Further causes are aged components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes.

Only the examination of the unit shows which of these causes actually applies. The individual points at a glance:

• aged electronic components
• cold solder joints
• moisture and corrosion at plug connections
• voltage spikes, for example from a weak battery or jump-starting

How can you tell that the 28556-4KJ0C is defective?

The airbag warning light in the instrument cluster lights up constantly or intermittently, a fault message appears in the instrument cluster, the diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared.

As long as such signs exist, airbags and seatbelt pretensioners may not trigger in an emergency. The light is therefore not a mere display, but a message about the state of the system.

Which vehicles is the 28556-4KJ0C fitted in?

The airbag control unit 28556-4KJ0C is fitted in these vehicles: Nissan Frontier D23 (2015-2020); Nissan Navara D23 (2015-2020). Before removal it is worth checking the part number against the label.

The vehicle list follows here:

• Nissan Frontier D23 (2015-2020)
• Nissan Navara D23 (2015-2020)

Comparing the part number on the unit with this page only ensures that the correct unit is present. Have the fault memory read out beforehand; the log 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 0 285 015 304, 28556-8Z325, 285569Z510, 28556EA10A, 98820 6KB0A, 98820 EB01D.

How does the repair of the 28556-4KJ0C work?

First have the fault memory read out and enclose the log with the unit, then disconnect the battery and remove the 28556-4KJ0C. Next create a repair order online and pack the unit well for sending. At Airbag24 itself, processing usually takes 3–4 working days.

There the unit is checked on the test bench, defective components are replaced, crash data is erased, and the functional test completes the work.

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 28556-4KJ0C get to Airbag24?

Either you send the unit as a parcel to Airbag24, or you book a UPS collection for an extra charge. After the repair, your own unit comes back by UPS.

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