Airbag control unit with part number 28556 2S700

What does the airbag control unit 28556 2S700 do?

At Nissan, the airbag control unit 28556 2S700 forms the control centre of the restraint system (SRS). It reads the crash sensors and decides in an emergency, within milliseconds, whether airbags and seatbelt pretensioners are triggered. After an accident it stores crash data and locks itself.

During operation the unit continuously checks its sensors, wiring and output stages. If it finds a fault, it creates an entry in the fault memory and alerts the driver.

The crash data form a separate memory area of their own. They cannot be removed like an ordinary finding via the diagnostic tool.

Why does the control unit 28556 2S700 fail?

The most common cause is crash data that remained in memory after an accident, even if no airbag triggered. Further causes are aged electronic components, moisture and corrosion on plug connections, and voltage spikes, for example from a weak battery or a jump start.

Crash data cannot be erased with an ordinary diagnostic tool, so the indication remains. Airbag24 removes this data in a targeted way during the repair.

The other causes concern the electronics themselves. Components age with time, solder joints can go cold, and moisture finds its way into the plugs.

How can you tell that the 28556 2S700 is defective?

Typical signs are an airbag warning light that lights up permanently or intermittently, an error message in the instrument cluster, no connection to the diagnostic tool, and a fault memory that cannot be cleared. With these signs, airbags and seatbelt pretensioners may not trigger in an emergency.

• The airbag warning light stays on permanently
• The airbag warning light lights up intermittently
• Error message in the instrument cluster
• The diagnostic tool cannot make contact with the control unit
• The fault memory cannot be cleared

In this case, have the fault memory read out before you change anything on the vehicle.

Which vehicles is the 28556 2S700 fitted in?

The control unit 28556 2S700 is fitted in these vehicles: Nissan Navara D22 (1997-2000) and D22 Facelift (2000-2005). The list is based on the details we hold for this unit.

The vehicles from our details are listed here:

• Nissan Navara D22 (1997-2000)
• Nissan Navara D22 Facelift (2000-2005)

Compare the part number on the label of the removed unit with this page to confirm that it is the right unit. Also have the fault memory read out beforehand, because only this result shows whether the control unit is at fault or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 28556VK300, 98820 EB01D.

How does the repair of the 28556 2S700 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit; then create a repair order online and send in the well-packed unit.

Airbag24 checks the unit on the test bench and replaces defective components. Afterwards Airbag24 erases the stored crash data and carries out a function test, before your own unit is sent back to you.

Processing at Airbag24 usually takes 3–4 working days. This period refers only to checking, repairing and testing in our own facility.

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 2S700 get to Airbag24?

You can send the unit in as a parcel, or have a UPS collection arranged for an extra charge. Airbag24 returns it to you by UPS after the repair.

Pack the control unit shockproof and enclose the printed repair order.