Airbag control unit with part number 90 562 544 BJ

What is the function of the airbag control unit 90 562 544 BJ?

The airbag control unit 90 562 544 BJ is an SRS control unit manufactured by Siemens (model 5WK4113A), equipped with a 68HC05B6 microcontroller. It was specifically designed for the Opel Omega A (1986–1993) and serves as the central control unit for the entire occupant protection system, including airbags and seatbelt pretensioners.

The primary task of this control unit is to process sensor data in order to activate the restraint systems precisely and at the right moment during a crash. After activation, it permanently stores so‑called crash data in its internal memory. This lockout prevents reuse without proper repair and a reset of the stored data.

In addition, the unit continuously monitors all connected components of the airbag system for proper functionality. Detected faults are recorded in the fault memory and indicated by the illumination of the airbag warning light on the instrument cluster.

Why does the control unit 90 562 544 BJ fail?

The most common cause of failure for the control unit 90 562 544 BJ is the storage of crash data after an accident. These data block the unit’s operation and cannot be erased using standard workshop diagnostic tools. Other defects arise from electrical disturbances such as short circuits, water damage, or reverse polarity during jump-start attempts.

Following activation of an airbag or seatbelt pretensioner, the control unit becomes internally locked. This condition is intentional, ensuring that the entire system undergoes thorough inspection and professional restoration. A simple replacement without resetting the unit is therefore not possible.

Hardware defects on the circuit board are also a frequent cause. These include damaged pins on the connector due to corrosion, broken solder joints, or faulty electronic components such as capacitors or the microcontroller itself. Such damage often results in complete loss of communication with the vehicle.

Internal errors, recorded as non‑erasable DTC codes (e.g., U1XXX, B1XXX) in the fault memory, likewise indicate a defect within the control unit. These errors prevent the system from being ready for use and cause the SRS warning light to remain constantly illuminated.

How can you recognize a defect in the 90 562 544 BJ?

A defect in the control unit 90 562 544 BJ primarily manifests as a continuously lit or flashing airbag warning light (SRS lamp) on the dashboard. Additionally, stored fault codes—especially after an accident—cannot be cleared using standard diagnostic equipment, and communication with the control unit breaks down.

The most obvious symptom is the active airbag warning light. It fails to extinguish after starting the vehicle, indicating a serious safety‑related fault that will prevent passing a mandatory technical inspection (TÜV).

Another clear sign is the failure of diagnostic communication. When a workshop attempts to read the fault memory using devices like TECH2 or a Bosch tester, messages such as “No communication with control unit” or “Control unit defective” frequently appear, as the unit no longer responds to requests.

Stored fault codes that cannot be reset are also a typical indicator. Internal errors or evidence of stored crash data keep the system locked until professional repair and a data reset have been performed.

In which models is the 90 562 544 BJ installed?

The airbag control unit with part number 90 562 544 BJ is specifically designed for vehicles of the Opel brand. It is mainly used in the Opel Omega A model years 1986–1993. At Airbag24, we professionally repair this control unit and restore full functionality.

At Airbag24, repair services for the control unit 90 562 544 BJ are available for the following model:

Opel: Omega A (1986–1993)

It is important to carefully verify the part number before removal, as similar variants such as 90 565 938 DC may exist. Double-checking ensures that the correct unit is sent for repair.

How is the 90 562 544 BJ professionally repaired?

Professional repair of the control unit 90 562 544 BJ at Airbag24 includes a detailed analysis, targeted correction of the root cause of the fault, and a final functional test. The focus is on resetting the stored crash data and replacing any defective electronic components on the circuit board.

Upon receipt at Airbag24, the control unit undergoes an initial inspection. Technicians use specialized equipment to read the internal fault memory, pinpointing the exact cause—whether a hardware defect or a data lockout.

The core of the repair is the so‑called SRS Crash Data Reset. During this process, all crash data stored after an accident and causing the unit to lock are completely removed, restoring the control unit to its factory settings. Simultaneously, internal non‑erasable fault codes (such as 9A6B or 65535) are cleared.

If a hardware defect is present, damaged components such as pins, capacitors, or the microcontroller are professionally replaced. Following repair, comprehensive tests are conducted to ensure flawless communication and functionality. We provide a 12-month warranty on every repair.

What are the benefits of repair?

Repairing the original airbag control unit 90 562 544 BJ is significantly more cost-effective than purchasing a new part. Cost savings often range from 50% to 70% compared to a new unit, which can cost between 500 and 750 euros. Additionally, the original component remains intact, ensuring compatibility.

A key advantage is retaining the original control unit. As it is the factory-installed part, no additional coding or re-learning procedures are required after installation. The repaired unit functions immediately—plug-and-play.

Repair also represents a sustainable solution. Rather than discarding a fully functional unit, only the defective components are selectively replaced. This not only saves money but also conserves valuable resources. With a 12-month warranty, repair offers a safe and reliable alternative.

What shipping options are available?

At Airbag24, we offer flexible and secure shipping options. You can send the defective control unit to us free of charge yourself, or arrange a convenient UPS pickup at your preferred location. For return shipping, we provide free standard UPS delivery, express options, and cash-on-delivery service.

For sending your removed control unit back to us, you have two choices: you can ship it at your own expense, or use our free online form. Alternatively, you can schedule a UPS pickup at an address of your choice (e.g., your home or workshop).

After successful repair, return shipping is available with the following options:

Free standard UPS delivery

UPS express delivery

Standard UPS delivery with cash-on-delivery

UPS express delivery with cash-on-delivery

Self-collection at our facility