Airbag control unit with part number 985107594R

What is the function of the airbag control unit 985107594R?

The airbag control unit 985107594R is the central control module for the occupant protection system in the Dacia Spring I. It continuously analyzes data from the acceleration sensors to precisely and millisecond‑fast deploy the airbags and seatbelt pretensioners in the event of a crash. Additionally, it stores system‑relevant fault and crash data.

As a safety‑critical component, its flawless operation is essential for the vehicle’s passive safety. It communicates via the vehicle’s internal data bus with other control units and the diagnostic system to ensure continuous system monitoring.

Following an impact, so‑called crash data are permanently stored in the control unit’s memory. This entry locks the system and prevents further use without professional repair.

Why does the control unit 985107594R fail?

The most common reason for repairing the control unit 985107594R is the storage of crash data after an accident, which locks the system. Other typical causes include electronic defects on the circuit board, such as faulty components (EEPROM, MOSFETs), corrosion damage caused by moisture, or cold solder joints.

After a collision, a “crash flag” is set in the internal non‑volatile memory (EEPROM/Flash). This entry permanently blocks the system, even if no external damage is visible. Simply clearing the fault memory using a diagnostic tool is no longer possible in this state.

Electronic components can also fail due to aging, temperature fluctuations, or voltage spikes. These include defective voltage regulators, blown driver stages (MOSFETs) for ignition circuits, or damaged memory chips that lead to an internal control unit error.

Environmental factors such as moisture can also attack conductive traces and solder joints on the board, causing short circuits or open circuits. Similarly, faults in the CAN‑bus transceiver can disrupt communication with the vehicle, leading to complete system failure.

How do you recognize a defect in the 985107594R?

A defect in the airbag control unit 985107594R primarily manifests as a constantly illuminated airbag warning light on the instrument cluster. Often, the control unit cannot be accessed with a diagnostic tool, or it reports an “internal error” that cannot be cleared.

The most noticeable sign is the red airbag warning lamp that does not turn off after starting the engine. This indicates a serious malfunction in the restraint system and its complete deactivation in an emergency.

During diagnostics at the workshop, specific fault codes are often read out, directly pointing to stored crash data or an internal hardware defect. In some cases, communication with the control unit via the diagnostic interface is completely impossible.

In which vehicles is the 985107594R installed?

The airbag control unit with part number 985107594R is specifically used in the Dacia Spring I. At Airbag24, this control unit is professionally refurbished for all variants of this model to restore full functionality of the safety system.

Repair services at Airbag24 are available for the following model:

Dacia Spring I (2021–present)

How does the repair of the 985107594R work?

Repair at Airbag24 begins with removing the defective control unit and sending it in. Our technicians perform a thorough analysis, reset the crash data, repair electronic defects at the component level, and then verify full functionality. You receive 2 years' statutory liability for defects on the repair.

Before removal, fault codes should be read out and documented. The control unit is then disassembled according to the manufacturer’s specifications and securely packaged for shipment to Airbag24.

At our specialized workshop, an initial inspection of the circuit board is carried out. Depending on the extent of the damage, repairs may include properly erasing crash data, replacing defective SMD components such as memory chips or MOSFETs, and fixing damage to conductive traces and solder joints.

After successful restoration and final functional testing, the control unit is returned. Following reinstallation, the fault memory in the vehicle must be cleared.