Airbag control unit with part number 98820-3SJ0B

What does the airbag control unit 98820-3SJ0B do?

The airbag control unit 98820-3SJ0B forms, as the central unit, the restraint system (SRS) in Nissan. It evaluates the signals from the crash sensors, decides within milliseconds in an accident whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously. It indicates faults via the airbag warning light.

After an accident, the unit stores crash data and locks itself.

The control unit remains active during operation and checks the sensors in the process.

Why does the control unit 98820-3SJ0B fail?

Units most often fail because of crash data stored after an accident, even when no airbag has deployed. Aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes are also involved.

Usual diagnostic tools do not remove this data. Airbag24 deletes it during the repair.

Aged electronic components and cold solder joints can occur independently of an accident and cause the unit to fail.

Moisture and corrosion at plug connections also affect the electronics, and voltage spikes, for example from a weak battery or a jump start, stress them further.

How can you tell that the 98820-3SJ0B is defective?

Typical is an airbag warning light in the instrument cluster that stays on permanently or intermittently. In addition, fault messages appear, the diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared.

While the defect exists, airbags and seatbelt pretensioners may fail to deploy in an emergency. Even a warning light that comes on only intermittently is a reason to have the system checked.

The light shows the fault and deserves prompt clarification.

Which vehicles is the 98820-3SJ0B fitted in?

The control unit 98820-3SJ0B is fitted in these vehicles: Nissan Sylphy B17 (from 2012).

The vehicles listed for this part number follow here.

• Nissan Sylphy B17 (from 2012)

Compare the part number on the label of the removed unit with this page; that only confirms that it is the right unit. A fault memory read-out gives information on whether the control unit itself is defective or whether a plug or cable is the cause. For that reason, have it read out in advance.

For the same vehicles, we also repair control units with the part numbers 28556-3RA0A, 28556-3RB0A, 28556-3RC0A, 28556-3RD0B, 28556-3RF0B, 28556-3RL0A.

How does the repair of the 98820-3SJ0B work?

First have the fault memory read out and attach the log to the unit. Then disconnect the battery, only then remove the control unit, create a repair order online and send the unit in well packed. Airbag24 tests it on the test bench, repairs defective components and carries out a function test; processing usually takes 3–4 working days.

The sequence is binding for your safety. The control unit may only be removed once the fault memory is secured and the battery is disconnected.

Afterwards your own unit is sent back to you. The 3–4 working days cover only the work at Airbag24, not the steps on your side or the shipping.

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 98820-3SJ0B get to Airbag24?

You send the unit as a parcel, or book UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

Put the printed repair order in the parcel and pack the control unit securely against shocks.