Airbag control unit with part number 5WK4116

What is the function of the airbag control unit 5WK4116?

The airbag control unit with part number 5WK4116 is the central control module of the Supplemental Restraint System (SRS) in the Daewoo Nexia N100 (1994–1997). It analyzes data from crash sensors and is responsible for precisely and promptly deploying airbags and seatbelt pretensioners in the event of a collision.

This unit acts as the brain of the passive safety system. It continuously monitors all connected components, including impact sensors, seat occupancy detectors, seatbelt pretensioners, and the airbag modules themselves. Under normal operating conditions, it ensures the system remains ready for use and alerts the driver to any malfunctions via the SRS warning light.

In the event of an impact whose severity and direction are classified as critical by the sensors, the control unit makes the activation decision within milliseconds. It ignites the necessary pyrotechnic charges in the airbags and seatbelt pretensioners to provide optimal protection for occupants. At the same time, relevant crash data—known as crash data—is permanently stored in the device’s internal memory.

Why does the 5WK4116 control unit fail?

The most common cause of failure for the 5WK4116 control unit is the storage of crash data after an accident, which permanently locks the device. Other causes include electronic defects on the circuit board, such as failed capacitors or memory chips, leading to internal errors like fault code B1111.

After an airbag deployment, the manufacturer intentionally locks the control unit. This safety measure prevents reuse without professional inspection. The stored crash data blocks the unit’s functionality even if the hardware itself remains undamaged. Simple clearing of the fault memory is then no longer possible.

In addition to accident‑induced locking, hardware aging can also lead to failure. Defective capacitors or faulty memory chips (EEPROM) on the circuit board are typical culprits. Likewise, cable damage or damage caused by static discharge during installation or removal can harm the sensitive electronics and result in total failure.

How do you recognize a defect in the 5WK4116?

A defective 5WK4116 airbag control unit primarily manifests as the SRS warning light remaining constantly illuminated in the instrument cluster. During diagnostics with a workshop tester, fault code B1111 (control unit defective) or a similar internal error code indicating a unit malfunction is often read.

The airbag warning light is the clearest sign of a problem in the restraint system. It indicates that the system is not functioning properly and that airbags may fail to deploy in the event of a crash. The light persists continuously after the vehicle is started.

During workshop diagnostics, fault code B1111—which directly points to an internal defect in the control unit—often cannot be cleared. In some cases, communication between the diagnostic tool and the airbag control unit is completely lost, providing another clear indication of a severe internal fault.

In which vehicles is the 5WK4116 control unit installed?

The 5WK4116 airbag control unit is specific to the Daewoo Nexia of the N100 series, produced between 1994 and 1997. At Airbag24, we offer professional repairs for this specialized control unit to restore the safety and functionality of the airbag system in these vehicles.

Specifically, this control unit is found in the following model:

- Daewoo Nexia N100 (model years 1994, 1995, 1996, 1997)

How is the 5WK4116 professionally repaired?

At Airbag24, the 5WK4116 control unit undergoes a thorough electronic analysis. Technicians erase the stored crash data and restore the device to its factory settings. Defective components, such as capacitors or memory chips, are replaced as needed, followed by a final functional test.

After removing the control unit and sending it to Airbag24, the repair process begins with a detailed diagnosis. First, the fault memory is read to confirm the exact cause. Then, the circuit board is inspected for visible and measurable defects, such as faulty capacitors, cold solder joints, or damaged traces.

The core of the repair is resetting the stored crash data. This is achieved through direct access to the control unit’s memory chip, restoring its original factory functionality. Upon completion of all work, the control unit undergoes a comprehensive functional test. We provide 2 years' statutory liability for defects on every repair.

Is Repairing the 5WK4116 Worth It?

Repairing the 5WK4116 offers substantial cost savings of up to 70% compared to purchasing an expensive new part. Since the original unit remains intact, no time-consuming coding or reprogramming is required on your vehicle. Additionally, you receive 2 years’ statutory liability for defects on the repair performed.

A new control unit can cost anywhere from 400 to over 750 euros, depending on the manufacturer and availability. Repair is a far more economical alternative that restores full functionality. Once installed, the repaired unit can typically be used immediately (plug-and-play), eliminating additional workshop fees for programming.