Airbag control unit with part number 28556-3RL0A

What does the airbag control unit 28556-3RL0A do?

The airbag control unit 28556-3RL0A is the central control unit of the restraint system (SRS) for Nissan. It evaluates the signals from the crash sensors, decides in an accident within milliseconds about the triggering of airbags and seatbelt pretensioners, and monitors the system continuously.

If it detects a fault, it reports this via the airbag warning light. After an accident the control unit stores crash data and locks itself.

To do this it works closely with sensors, wiring and firing modules. A fault can therefore also lie outside the control unit, and this is exactly what the evaluation of the fault memory is for.

Why does the control unit 28556-3RL0A fail?

For the control unit 28556-3RL0A the most common cause after an accident is stored crash data, even if no airbag has deployed. Further causes are ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data remains stored after the accident, even if no airbag has opened. It cannot be deleted with a standard diagnostic tool. Airbag24 removes it during the repair.

The other causes concern the electronics themselves. Components age, solder joints can turn cold, and moisture or corrosion at the plugs disturbs the signal transmission. Voltage spikes, for example from a weak battery or jump-starting, can also strain components.

How can you tell that the 28556-3RL0A is defective?

A defect at the 28556-3RL0A shows up through the airbag warning light in the instrument cluster, which lights up permanently or intermittently, through a fault message in the instrument cluster, through a missing connection of the diagnostic tool to the control unit, and through a fault memory that cannot be cleared.

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

Have the system checked promptly once the light comes on. Airbags and seatbelt pretensioners may not trigger in an emergency.

Which vehicles is the 28556-3RL0A fitted in?

The control unit 28556-3RL0A matches the vehicles on record for Nissan. It is fitted in these vehicles: Nissan Sylphy B17 (from 2012).

The known vehicles for this part number are shown in the following overview.

• Nissan Sylphy B17 (from 2012)

Compare the part number on the label of the removed unit with this page. This only ensures that it is the correct unit. Have the fault memory read out first, because only this log shows whether the control unit is defective or whether a plug or cable is the cause.

How does the repair of the 28556-3RL0A work?

First have the fault memory read out and enclose the log. Then disconnect the battery and remove the control unit 28556-3RL0A; afterwards create the repair order online and send the unit in well packed. At Airbag24 itself, testing, repairing and checking usually take 3–4 working days.

The order is fixed for safety reasons. The control unit is removed only after the battery has been disconnected.

Airbag24 tests the unit on the test bench, replaces defective components, deletes the stored crash data and carries out a function test.

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 28556-3RL0A get to Airbag24?

You send the control unit 28556-3RL0A as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 returns it by UPS.

Enclose the printed repair order in the parcel and pack the unit shock-proof.