Airbag control unit with part number 98820-5UB0A

What is the function of the airbag control unit 98820-5UB0A?

The airbag control unit 98820-5UB0A is the central control module for the occupant protection system in the Infiniti QX50, model series P15 (from model year 2017 onward). It continuously analyzes data from the vehicle’s sensors to precisely and millisecond‑fast deploy the airbags and seatbelt pretensioners in the event of a crash.

As the “brain” of the passive safety system, this control unit interprets signals from acceleration and yaw rate sensors. Based on this data, it determines the type and severity of a collision.

On the basis of this analysis, the unit decides which restraint systems—such as front and side airbags or seatbelt pretensioners—should be activated to maximize occupant protection. After an activation, the unit permanently stores the relevant crash data.

Why does the control unit 98820-5UB0A fail?

The most common cause of failure for the control unit 98820-5UB0A is the storage of crash data after an accident, which can lock the system. Other causes include internal hardware faults on the circuit board that lead to communication interruptions or trigger specific diagnostic trouble codes such as B142A and B1427.

Following a collision—even minor ones where the airbags did not deploy—the control unit records a crash event. These data are intentionally designed by the manufacturer to be non‑erasable by standard diagnostic tools, necessitating professional repair.

Another frequent defect involves internal malfunctions within the control unit itself. These may include cold solder joints, faulty microcontrollers, or defective memory chips. Such hardware issues often manifest as the aforementioned error codes B142A or B1427, preventing the system from completing its self‑diagnosis successfully.

How do you recognize a fault in the control unit 98820-5UB0A?

A malfunction of the airbag control unit 98820-5UB0A is primarily indicated by the airbag warning light illuminating constantly or intermittently in the instrument cluster. It is also typical that workshop diagnostic tools can no longer establish communication with the control unit or read out specific diagnostic trouble codes.

The most obvious sign is the illuminated airbag warning lamp. This indicates that the safety system is not fully operational and may fail to deploy correctly in the event of a crash. The light remains on continuously after the vehicle is started.

In a specialized workshop, the problem often becomes apparent when the control unit is no longer accessible via the OBD interface. When a technician attempts to read the fault memory, communication fails—even though all other control units in the vehicle remain reachable.

If diagnostic trouble codes are read, entries such as B142A or B1427 particularly point to an internal, unit‑level fault that cannot be resolved through software clearing alone and requires hardware repair.

In which vehicles is the control unit 98820-5UB0A installed?

The airbag control unit with part number 98820-5UB0A is specifically used in Infiniti vehicles. It is designed for the second‑generation QX50 model series (internal designation P15), produced starting from model year 2017. Airbag24 specializes in repairing this module.

At Airbag24, the part number 98820-5UB0A is professionally refurbished for the following model:

Infiniti QX50 (model series P15, 2017–present)

How is the control unit 98820-5UB0A professionally repaired?

Professional repair at Airbag24 begins with an incoming inspection to verify the fault. Stored crash data are then reset at the hardware level, and internal defects are corrected by replacing faulty components on the circuit board. A final test ensures full functionality. Each repair comes with 2 years' statutory liability for defects.

Upon receipt of the removed control unit at Airbag24, our technicians conduct a systematic analysis to pinpoint the exact cause of the fault. This includes checking whether crash data are stored or if there is an internal hardware issue.

Restoration is carried out through specialized interventions directly on the electronics. Stored crash data are irreversibly erased, returning the unit to factory settings. For internal faults, defective components such as processors or memory chips are precisely replaced.

With over 20 years of experience and more than 20,000 control unit repairs completed, a high success rate is guaranteed. Following repair, the control unit is fully functional again and typically does not require reprogramming, simplifying reinstallation.