Airbag control unit with part number SA311250000

What is the function of the SA311250000 airbag control unit?

The SA311250000 airbag control unit from Delphi is the central control module for the passive safety system in the Hyundai Equus LZ/YJ (1999–2009). It continuously analyzes data from crash sensors and ensures that, in the event of a collision, the airbags and seatbelt pretensioners are deployed precisely and at the optimal moment.

As a core component of the restraint system, this control unit coordinates all safety‑related actuators. It constantly monitors system integrity and communicates with other vehicle modules to ensure flawless operation.

Technically, this device is closely related to Bosch part number 0 285 010 174 and serves as a direct replacement or repair option for this variant in the specified vehicle models.

Why does the SA311250000 control unit fail?

The most common cause of failure for the SA311250000 control unit is the storage of crash data after an accident, which triggers an internal lockout. Other causes are purely electronic, such as defective chips or capacitors due to aging, as well as corrosion on connectors caused by moisture ingress.

Following a collision, the unit stores permanent crash data (error code B1620), causing the airbag warning light to remain illuminated and the system to be locked for safety reasons. This is an intentional feature, not a software defect.

Internal hardware failures are also frequent. Aging components like capacitors or processors can fail, often triggered by voltage spikes in the vehicle’s electrical system. These issues frequently result in internal communication errors, diagnosed with error code B1000.

External factors, such as water damage, can lead to corrosion on connectors and the circuit board, completely disrupting communication with the vehicle or diagnostic tools.

It is important to note that several compatible part numbers exist for the Hyundai Equus, including 95910-3N000 (Delphi SA3112500-00), 95910-3N010 (Delphi SA3119700-00 / Bosch 0 285 010 988), and 95910-3N200 (Delphi SA3118600-00). Therefore, verifying the exact part number or VIN before proceeding with repairs is essential.

How do you recognize a fault in the SA311250000?

A malfunction of the SA311250000 control unit primarily manifests as a permanently illuminated airbag warning light on the dashboard. Additionally, the unit may become unreachable to diagnostic equipment, making fault analysis impossible. In rare cases, the warning light may glow faintly, or the instrument cluster illumination may flicker when locking the vehicle.

The most obvious sign is the persistently lit airbag indicator. It fails to turn off after starting the engine, indicating a serious stored error or internal defect.

Another clear symptom is the lack of communication. If a workshop attempts to read the fault memory via the OBD interface, the airbag control unit no longer responds to diagnostic requests.

Specific and rarer symptoms that may point to a fault in this control unit include a slight glow of the airbag light when the ignition is off, or a brief flash of the instrument cluster illumination when the vehicle is locked.

In which vehicles is the SA311250000 control unit installed?

The airbag control unit with part number SA311250000 was specifically designed by Delphi for the luxury sedan Hyundai Equus, model series LZ/YJ. It is used in vehicles manufactured between 1999 and 2009.

At Airbag24, repairing this control unit is an established service for the following model:

Hyundai: Equus (model series LZ/YJ, years 1999–2009)

Since various, sometimes interchangeable control units exist for this vehicle generation, matching the part number printed on the unit before removal and shipment is crucial to ensure accurate and prompt processing.

How is the SA311250000 professionally repaired?

Professional repair of the SA311250000 involves precise diagnostics, safe resetting of stored crash data, and inspection or replacement of faulty electronic components. Final functional tests restore full system integrity, and 2 years' statutory liability for defects is provided on the repair.

After sending the removed control unit to Airbag24, restoration follows a proven multi‑step process that guarantees reliable functionality.

First, an in-depth diagnosis is performed at the component level. Technicians read out internal fault memories and crash data to pinpoint the exact cause of the malfunction.

Subsequently, the stored crash data is securely erased at the hardware level. If the analysis reveals additional defective components such as chips or capacitors, these are replaced with new, high-quality parts.

Upon completion of the repair, the control unit undergoes comprehensive testing to verify proper communication and functionality of all system components. This repair offers a cost-effective alternative to expensive replacement and restores full safety.