Airbag control unit with part number 5WK43925-95640

What is the function of the airbag control unit 5WK43925-95640?

The airbag control unit 5WK43925-95640 is a central control module manufactured by Bosch, serving as the core component of the vehicle’s passive safety system (SRS) in Hyundai cars. It processes data from acceleration sensors in real time to detect collisions and, when necessary, precisely deploy the airbags and pyrotechnic seatbelt pretensioners.

As the “brain” of the restraint system, this module determines within milliseconds which safety components need to be activated to provide optimal protection for occupants. It continuously monitors all connected ignition circuits, sensors, and internal system integrity.

Technically, this control unit is compatible with several alternative original part numbers from Hyundai/Mobis and functions identically. These include part numbers 95910-1J100, 95910-1J400, and 95910-C8100. Repairs are possible for all these variants.

Why does the control unit 5WK43925-95640 fail?

The most common causes of failure for the control unit 5WK43925-95640 are stored crash data following an accident, which locks the device, as well as internal electronic hardware defects. The latter often manifest as error code B1000 (“internal control unit fault”) and can occur even without a collision.

After an airbag deployment, the control unit permanently stores a crash record in its internal memory. This entry cannot be erased using standard diagnostic tools and results in deactivation of the entire airbag system. In this state, the unit remains locked, although the hardware itself is often still fully functional.

Independently of accidents, electronic components on the circuit board may also fail. Typical causes include defects in memory chips (EEPROM/Flash) due to aging or data corruption, faulty voltage regulators in the power supply, or defective ignition circuit drivers (squib driver ICs). Solder joint issues caused by thermal stress and vibrations within the vehicle are another well-known source of failure.

How do you recognize a defect in the airbag control unit?

A defect in the control unit 5WK43925-95640 primarily manifests as a continuously illuminated SRS or airbag warning light on the instrument panel. Additionally, internal error codes such as B1000 or the message “Crash Data Stored,” which cannot be cleared, can be found in the fault memory.

The warning light in the cockpit fails to extinguish after starting the vehicle, indicating a serious, safety‑relevant system fault. This is the clearest sign for the driver that immediate inspection at a specialized workshop is required.

The most critical and dangerous symptom is the complete deactivation of the passive safety system. As long as the fault persists, airbags and seatbelt pretensioners will no longer provide any protection to vehicle occupants in the event of a future collision.

In which vehicles is the control unit 5WK43925-95640 installed?

The airbag control unit with part number 5WK43925-95640, along with its identical counterparts 95910-1J100, 95910-1J400, and 95910-C8100, is specifically fitted in the newer generation of the Hyundai i20. Repair services cover both the base model and the facelift version.

At Airbag24, professional repair services for this control unit are offered for the following Hyundai models:

Hyundai i20 (Type BC), model years 2020–2024

Hyundai i20 Facelift (Type BC), from model year 2023 onward

How is the control unit 5WK43925-95640 professionally repaired?

Professional repair begins after submission to Airbag24 with a comprehensive electronic diagnosis performed on a dedicated test bench. Depending on the nature of the fault, either the stored crash data is cleared by accessing the internal memory, or hardware repairs are carried out at the component level before a final test confirms full functionality.

The initial inspection simulates vehicle operation and reads the internal fault memory to distinguish between a pure data storage issue and a genuine hardware defect.

For stored crash data, technicians directly access the EEPROM or Flash memory chip. The dataset is read out, crash segments are reset to factory settings—without altering vehicle‑specific coding such as the VIN—and the cleaned data is rewritten.

If an electronic fault like error code B1000 is present, repairs are conducted at the component level. Under a microscope, defective parts such as voltage regulators, memory ICs, or ignition circuit drivers are identified and replaced with new, high‑quality components. Finally, the unit undergoes another test on the bench to ensure it functions like a brand‑new part. Each repair comes with a 12‑month warranty.

What shipping options are available at Airbag24?

For a hassle-free process, Airbag24 offers flexible shipping options. You can either return your defective control unit free of charge yourself or arrange a paid UPS pickup at your preferred location. For the return shipment, both free and express options are available, including cash-on-delivery.

For the outbound shipment, you have two choices: you can send the package to us at your own expense, or conveniently add the UPS pickup service directly during online ordering.

After successful repair, the return shipment can be arranged via the following options:

Free UPS standard shipping (delivery in 1–3 business days).

UPS express shipping for faster delivery (1–2 business days).

UPS standard shipping with cash-on-delivery (1–3 business days).

UPS express shipping with cash-on-delivery (1–2 business days).

Alternatively, you can also pick up the repaired control unit in person at our company premises.