Airbag control unit with part number B8555-78J02

What is the function of the airbag control unit B8555-78J02?

The airbag control unit with part number B8555-78J02 is the central control module for the passive safety system in the Infiniti G20 P11. It continuously processes data from the acceleration sensors to trigger, within milliseconds in the event of a crash, essential restraint systems such as airbags and seatbelt pretensioners.

As the “brain” of the airbag system, this control unit is responsible for monitoring, controlling, and activating all relevant components. It performs a self-test every time the vehicle is started, ensuring that all sensors and actuators are operational. Therefore, proper functioning of this unit is essential for occupant safety.

A failure or malfunction of the B8555-78J02 control unit inevitably results in complete failure of the airbag system. This poses a significant safety risk, as no protection from the passive restraint systems would be provided in an emergency.

What types of defects occur in B8555-78J02?

The most common causes of failure for the B8555-78J02 control unit are stored crash data following an accident, which can lock the device. Other typical issues include electronic malfunctions caused by water damage leading to corrosion, as well as spontaneous failures of internal electronic components due to aging.

After a crash in which the airbags have deployed, the control unit stores so‑called crash data in non‑volatile memory. These data cannot be erased using standard diagnostic equipment and permanently disable the unit’s functionality. A professional repair can unlock this lock and reset the control unit.

Water damage is another widespread source of failure. Ingressing moisture causes corrosion at solder joints and on circuit traces, resulting in short circuits and implausible signals. Spontaneous electronic faults—such as those affecting processors or memory chips—can also occur without external influence, impairing the control unit’s operation.

How do you recognize a defect in the B8555-78J02 control unit?

The clearest symptom of a defect in the B8555-78J02 airbag control unit is the persistent illumination or flashing of the red SRS warning light (Supplemental Restraint System) on the instrument cluster. This warning indicates a fault in the restraint system and requires immediate inspection.

When the SRS warning light is illuminated, it means the airbag system is disabled and will not deploy in the event of a crash. The error code stored in the control unit provides critical clues to the service workshop regarding the exact cause. Analyzing these codes is the first step toward successful diagnosis and repair.

In which models is B8555-78J02 installed?

The airbag control unit with part number B8555-78J02 is specifically designed for the Infiniti G20 of the P11 series. It was installed in vehicles of this series manufactured between 1998 and 2002.

At Airbag24, we specialize in repairing this control unit for the following specific model:

Infiniti G20 (P11 series) | Model years 1998–2002

How is B8555-78J02 professionally repaired?

At Airbag24, the repair of the B8555-78J02 control unit follows a strict, systematic process. Upon receipt of the unit, our technicians perform a comprehensive diagnosis to pinpoint the exact source of the fault. This involves analyzing error codes and inspecting the electronics for visible or measurable damage.

Depending on the nature of the fault, stored crash data are reset using specialized procedures, or defective electronic components on the circuit board are identified. Only original‑equipment components are used for replacement, fully restoring factory‑level functionality and safety.

Following repairs, the control unit undergoes a final functional test on a test bench. This ensures that all parameters meet manufacturer specifications and that the unit operates flawlessly once again. We provide a 12‑month warranty on every repair performed.

What shipping options are available at Airbag24?

For repairing your B8555-78J02 control unit, Airbag24 offers flexible and secure shipping options. You can send the unit yourself or take advantage of our convenient UPS pickup service from your preferred location. For return shipping, choose between free standard delivery and faster express options.

For outbound shipping, you have two choices: either ship the removed control unit directly to us, or arrange for UPS pickup at the time of placing your order. This allows for a convenient and speedy handling, whether from your workshop or from home.

After the repair is completed, several return options are available to you: free UPS Standard shipping, faster UPS Express shipping, and both options also available with cash on delivery. Alternatively, in-person pickup at our premises is also possible.