930925 - Gurtstraffer Fahrerseite Kurzschluss/ Masse (control unit defective) airbag control unit fault

What does error code 930925 mean in the airbag control unit?

Error code 930925 indicates a critical electrical fault in the ignition circuit of the driver’s seatbelt pretensioner. Specifically, a short circuit to ground has been detected, and the error message often points directly to an internal hardware defect in the airbag control unit as the primary cause. This is a safety‑related fault that compromises the entire restraint system.

The control unit continuously monitors the resistance of the ignition circuits for all pyrotechnic components, such as the seatbelt pretensioner. If the measured value deviates significantly from the nominal value and suggests a ground short, error code 930925 is stored, and the airbag warning light illuminates to alert the driver.

The addition “control unit defective” is crucial here. It indicates that the issue may not be limited to external components like wiring or the pretensioner itself; rather, the internal processing and diagnostic electronics on the control unit’s circuit board could also be damaged, rendering the component unable to reliably perform its safety function.

How do you recognize error code 930925?

The primary and unmistakable symptom is the permanently illuminated airbag warning light on the instrument cluster. Additionally, a diagnostic message such as “restraint system malfunction” or “airbag/pretensioner malfunction” may appear on the vehicle’s onboard computer display. In some cases, communication with the control unit via diagnostic tools may be blocked.

The airbag warning light fails to extinguish after starting the vehicle. This is a clear indication that the system has detected a severe, persistent fault and will either fail to deploy correctly—or not at all—in the event of a crash.

A key diagnostic feature is the persistence of the fault even after the driver’s seatbelt pretensioner and associated wiring have been inspected or replaced. If error code 930925 remains active, a defect within the airbag control unit itself is by far the most likely cause.

What causes error code 930925?

The causes are varied but generally relate to electrical connections and the components themselves. Common culprits include short circuits in the wiring harness, a faulty seatbelt pretensioner, or corroded connectors. However, very often the root cause lies in an internal hardware failure on the airbag control unit’s circuit board—such as defective capacitors or moisture damage.

A short circuit in the wiring harness between the airbag control unit and the seatbelt pretensioner is a frequent external source of trouble. Damaged insulation or kinked wires can inadvertently create unwanted ground contacts.

The seatbelt pretensioner itself may suffer from an internal electrical fault. Corroded or loose contacts at the system’s connectors can also trigger this error. Similarly, a defective coil spring in the steering wheel can lead to secondary malfunctions in the airbag system.

The most serious cause is a defect within the control unit itself. Internal hardware issues—such as damaged circuit boards, faulty capacitors, or damage caused by ingress of moisture—directly result in the storage of error code 930925.

This fault often occurs alongside other internal control unit errors. Watch for accompanying codes like 93F5 / 93F7 (sensor power supply), 93F9 (power reserve supply abnormal), or the general faults B1000 and 930ABD—all of which point to a defective control unit.

In which vehicles does error code 930925 occur?

Error code 930925 is a specific issue primarily affecting BMW models from the F-series. Vehicles produced roughly between 2011 and 2021 are impacted, including popular 1 Series, 2 Series, 3 Series, and 4 Series models, as well as their sporty M variants.

At Airbag24, we repair airbag control units exhibiting error code 930925 for the following models:

BMW 1 Series: F20 five-door (2011–2019), F21 three-door (2012–2019)

BMW 2 Series: F22 coupe (2013–2021), F23 convertible (2013–2021)

BMW 3 Series: F31 touring (2012–2019), including LCI models

BMW 4 Series: F32 coupe (2013–2020), F33 convertible (2014–2021), F36 Gran Coupe (2014–2021)

BMW M4: F82 coupe (2014–2020)

How is error code 930925 professionally repaired?

Professional repair requires removing the airbag control unit and sending it to a specialized laboratory. There, the device is opened, the circuit board analyzed, defective electronic components such as capacitors or ICs replaced, and finally all fault codes—as well as any crash data—are erased. A final test ensures full functionality.

The process begins in the workshop with a thorough diagnosis using professional software (e.g., ISTA) to rule out external causes. Subsequently, the control unit—typically located beneath the driver’s seat or in the center console—is carefully dismantled.

After submission to Airbag24, the repair is performed at the component level. Our technicians open the housing and conduct a visual and electrical test of the circuit board. Defective components responsible for ground shorts are precisely desoldered and replaced with new, high-quality parts. Any corrosion damage is carefully removed.

A crucial step is completely erasing the fault memory and any crash data stored in the system. This restores the control unit to its factory settings. Following the repair, the device is tested on a bench to ensure flawless operation before being returned to you. We provide a 12-month warranty on all repairs.

Is it worth repairing the control unit?

Yes, repair is the most cost-effective solution. Compared to a new part, which can cost around €1,500 at BMW, repair offers substantial savings. Moreover, a repaired control unit is ready for immediate use (plug-and-play) and eliminates the need for time-consuming re-coding in your vehicle.

The biggest advantage is the cost savings. Repairing the unit is significantly cheaper than purchasing a new one from an authorized dealer. You receive a fully functional, tested component at a fraction of the price of a new part.

An additional benefit is the time and effort saved. Since the repaired control unit is returned with the original vehicle configuration, there’s no need for expensive, time-consuming programming or coding at a specialized workshop. Installation is straightforward, and the system is immediately operational.