Airbag control unit with part number 28556 7F001

What does the airbag control unit 28556 7F001 do?

The airbag control unit 28556 7F001 is the central control unit of the restraint system (SRS) for Nissan. It evaluates the signals from the crash sensors and decides in an accident which airbags and seatbelt pretensioners are triggered. After an accident it stores crash data and locks itself.

The unit monitors the entire system continuously and detects deviations in the sensors, firing circuits and connections. The evaluation takes place in fractions of a second, so no time is lost in an emergency.

It records faults in the fault memory and shows them via the airbag warning light in the instrument cluster. Only the repair lifts the lock after an accident.

Why does the control unit 28556 7F001 fail?

The main cause is stored crash data, which was saved after an accident, even if no airbag has deployed. A normal diagnostic tool cannot erase it. Other causes include ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data remains in the unit even if no airbag fired after the accident. That the data can be erased means that Airbag24 removes it during the repair.

Ageing electronic components and cold solder joints can cause connections to break. Moisture and corrosion at plug connections produce transition resistances.

Voltage spikes occur, for example, with a weak battery or a jump start. Which cause is present in your unit is shown only by the inspection.

How can you tell that the 28556 7F001 is defective?

The airbag warning light in the instrument cluster lights permanently or intermittently, a fault message appears in the instrument cluster, the diagnostic tool does not connect to the control unit, and the fault memory cannot be cleared.

The airbag warning light in the instrument cluster is the clearest sign. When it lights permanently or comes on intermittently, the system has detected a fault in the restraint system. A fault message in the instrument cluster fits this.

If the diagnostic tool cannot connect to the control unit and the fault memory remains, the control unit itself may be affected. Airbags and seatbelt pretensioners may then fail to trigger in an emergency. Please have the finding checked promptly.

Which vehicles is the 28556 7F001 fitted in?

The control unit 28556 7F001 is fitted in these vehicles: Nissan Terrano R20 (1993-2007).

We know of the following models for this part number:

• Nissan Terrano R20 (1993-2007)

Check the part number on the label of the removed unit and compare it with this page. This only confirms that you have the correct unit. Have the fault memory read out beforehand, because only it 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 285001109, 285001480, 28556 8F000, 285562X100, 285562X11C, 988202X325.

How does the repair of the 28556 7F001 work?

Have the fault memory read out and enclose the log. Then disconnect the battery and only after that remove the control unit. Create the repair order online and send the well-packed unit. Airbag24 generally needs 3–4 working days for testing, repairing and checking.

This order is binding for safety reasons. The battery is disconnected only after the read-out, and removal follows last.

At Airbag24 the unit is inspected on the test bench, defective components are replaced, crash data is erased and a function test is carried out. Afterwards 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 7F001 get to Airbag24?

You send the control unit 28556 7F001 as a parcel, or you book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

Enclose the printed repair order and pack the unit shock-resistant so that it arrives undamaged.