Airbag control unit with part number 5WK4117

What is the function of the airbag control unit 5WK4117?

The airbag control unit with part number 5WK4117 is the central control module for the occupant protection system (SRS) in the Daewoo Aranos A150 (model years 1990–1999). It is responsible for processing sensor data and precisely activating airbags and seatbelt pretensioners in the event of a crash to protect occupants.

As an SRS module (Supplemental Restraint System), it continuously monitors all safety‑related components of the airbag system. Upon impact, it processes information from the crash sensors and determines within milliseconds which restraint devices need to be deployed.

Additionally, it manages the system’s fault memory and ensures safe deactivation after a crash to prevent unintended activations.

Why does the 5WK4117 control unit fail?

A failure of the 5WK4117 control unit is most commonly caused by stored crash data following an accident, which permanently locks the device. Other causes include hardware defects on the circuit board, aging capacitors, or external factors such as vibrations and cable breaks that lead to internal errors like code B1111.

After an airbag deployment, irreversible crash data is recorded in the control unit’s internal memory. This lock serves as a safety measure, preventing reuse until it is professionally reset through specialized repair procedures.

Electronic components such as capacitors can lose capacitance over time, leading to malfunctions. Cold solder joints on the circuit board—often caused by thermal stress and vehicle vibrations—are also a common source of failure.

A frequent diagnostic code indicating a serious internal defect is error code B1111 (control unit defective). This code cannot be cleared using standard diagnostic tools.

How do you recognize a defect in the 5WK4117?

A defect in the 5WK4117 control unit primarily manifests as a constantly illuminated or flashing SRS warning light on the instrument cluster. Additionally, fault codes such as B1111 (control unit defective) or B01 may appear; these codes reappear immediately after attempts to clear them, signaling a severe internal issue.

The most obvious sign is the active airbag warning light, indicating to the driver that the entire restraint system is disabled and no airbags or seatbelt pretensioners will deploy in the event of a crash.

When diagnosing via the OBD2 interface, error code B1111 is often displayed. This specific code directly points to an internal hardware or memory fault within the control unit itself, confirming the need for repair.

In which vehicles is the 5WK4117 control unit installed?

The airbag control unit with part number 5WK4117 was specifically developed for models manufactured by Daewoo. At Airbag24, we regularly repair this control unit for the following vehicle model, ensuring high expertise and reliability in its restoration.

The primary application for this control unit is:

Daewoo Aranos A150 (model years 1990–1999)

It is typically mounted in the center console, for example beneath the handbrake lever or in the front footwell of the vehicle.

How is the 5WK4117 control unit professionally repaired?

Professional repair of the 5WK4117 control unit at Airbag24 includes reading the fault memory, selectively erasing stored crash data, and restoring the hardware. Defective components such as capacitors are replaced, and the circuit board is thoroughly inspected before testing the unit’s full functionality.

Before removal, it is essential to disconnect the vehicle battery (starting with the negative terminal) and wait at least 10 minutes to allow any residual charge in the capacitors to dissipate. The use of ESD protection is strongly recommended to avoid damaging sensitive electronics.

Upon submission to Airbag24, a detailed analysis is performed. Using specialized software and equipment, crash data is completely erased from memory, returning the control unit to its factory‑original state.

Simultaneously, a physical inspection of the circuit board takes place. Technicians replace aged or defective components and repair any damage to the conductive traces. Following successful repair and a final test, the control unit is fully operational again and returned with 2 years’ statutory liability for defects.

Is repairing the 5WK4117 worthwhile?

Repairing the 5WK4117 control unit is an economically and technically sensible alternative to costly replacement. It offers significant cost savings, as new parts can cost up to €750, while repair is considerably cheaper. Moreover, the original component remains intact, avoiding potential compatibility issues.

The biggest advantage lies in the significant cost reduction. Instead of purchasing an expensive new part, the existing defective unit is expertly refurbished.

Since the original control unit is repaired, there’s no need for time-consuming coding or programming after reinstallation. After repair, the device is “plug-and-play” and can be directly reinstalled in the vehicle.