Airbag control unit with part number 98820-4BY0A

What does the airbag control unit 98820-4BY0A do?

The airbag control unit 98820-4BY0A is the control unit of the restraint system (SRS) in Nissan. It processes the signals from the crash sensors, determines in an accident within milliseconds which airbags and seatbelt pretensioners are triggered, and checks the system continuously. After an accident it stores crash data and locks itself.

The check runs in the background even when nothing happens. Faults found are stored in a memory and reported via the airbag warning light.

Why does the control unit 98820-4BY0A fail?

The most common cause with the 98820-4BY0A is crash data from an earlier accident, which a normal diagnostic tool cannot delete. Aged components, moisture at plug connectors and voltage spikes come on top of that.

The crash data is stored even when no airbag was triggered in the accident. Besides this, these causes come into consideration:

• aging of the electronic components
• cold solder joints
• corrosion and moisture at the plugs
• voltage spikes, for example with a weak battery or jump-starting

How can you tell that the 98820-4BY0A is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently, and a fault message appears at the same time. The diagnostic tool then finds no connection to the 98820-4BY0A, and the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may therefore not trigger.

The warning light checks itself when the ignition is switched on. If it stays lit afterwards or comes back while driving, this indicates a fault in the system. This finding can be narrowed down further by reading out the fault memory.

Which vehicles is the 98820-4BY0A fitted in?

The airbag control unit 98820-4BY0A is fitted in the following vehicles: Nissan X-Trail T32 (2014-2017) and T32 Facelift (2017-2022).

This list results from the part number:

• Nissan X-Trail T32 (2014-2017)
• Nissan X-Trail T32 Facelift (2017-2022)

Compare the part number on the label of the removed unit with this page so that the correct unit is processed. Whether the control unit is defective only the read-out fault memory shows, because a connector or cable can be the cause just as well. Therefore have the fault memory read out beforehand.

For the same vehicles, we also repair control units with the part numbers 28556-4CG0A, 28556-4CH0A, 28556-4CJ0A, 28556-4CM0A, 28556-4CS0A, 98820-4CG0A.

How does the repair of the 98820-4BY0A work?

First have the fault memory read out and attach the log. Then disconnect the battery, remove the control unit 98820-4BY0A, create a repair order online and send the unit in well packed. Checking, repairing and testing at Airbag24 normally take 3–4 working days.

The order is fixed for safety reasons. At Airbag24 the unit is checked on the test bench, defective components are repaired, the stored crash data is deleted and a function test is carried out. Your own unit then 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 98820-4BY0A get to Airbag24?

You send the 98820-4BY0A as a parcel or book a UPS collection for an extra charge. After the repair, the unit comes back to you by UPS.

The printed repair order goes into the parcel, and the unit is packed shock-proof so that it survives transport.