Airbag control unit with part number 51935305

What does the airbag control unit 51935305 do?

The airbag control unit 51935305 is the central control unit of the SRS restraint system for Fiat. It processes the signals from the crash sensors and triggers the appropriate airbags and seatbelt pretensioners within a very short time in an accident. After an accident, it stores crash data and locks itself.

The system is monitored throughout operation. If the unit detects a fault, it reports it via the airbag warning light.

On the housing, you will find the manufacturer number Bosch 0285011843 in addition to the part number. The lock ends only with the repair.

Why does the control unit 51935305 fail?

Stored crash data is the most common cause for the 51935305, even if no airbag has deployed. A normal diagnostic tool cannot erase it; Airbag24 removes it during the repair. In addition, aged components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes play a role.

The data arises in the unit itself after an accident. Because it is stored there, an attempt to erase it on the vehicle does not help.

The other causes concern ageing and environmental influences. Electronic components age, solder joints can go cold, and moisture attacks the plug contacts. Voltage spikes, for example from a weak battery or from connecting a jump start, can also harm the unit.

How can you tell that the 51935305 is defective?

A defect on the 51935305 shows itself mainly through the airbag warning light in the instrument cluster, which stays on permanently or intermittently. In addition, a fault message appears in the instrument cluster, the diagnostic tool gets no connection to the control unit, or the fault memory cannot be cleared.

As long as the light is on, the airbags and seatbelt pretensioners may not deploy in an emergency. This also applies when the car shows no problems in everyday use.

A connection fault between the diagnostic tool and the control unit is also a sign that a check can clarify.

Which vehicles is the 51935305 fitted in?

This control unit 51935305 is installed in these vehicles: Fiat 500 312 (2007-2024). The assignment depends on the part number of the unit.

The list of assigned vehicles follows here:

• Fiat 500 312 (2007-2024)

Compare the part number on the label of the removed unit with this page; this only confirms that you have the right unit. Have the fault memory read out in advance, because the result shows whether the control unit is defective or whether a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers 51782985, 51870005, 51897810, 51918659, 51963734, 519637734.

How does the repair of the 51935305 work?

On the 51935305, first have the fault memory read out and enclose the log. Then disconnect the battery, remove the control unit and create a repair order online. Then pack the unit carefully and send it in. At Airbag24, checking, repairing and testing usually take 3–4 working days.

After the check at Airbag24, the repair, the erasure of the crash data and a function test follow. Only then is your own unit sent back to you.

Our repairs come with 2 years' statutory liability for defects. The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

How does the control unit 51935305 get to Airbag24?

You send the control unit 51935305 as a parcel, or you book a UPS collection for an extra charge. The return of the repaired unit is made by UPS.

The printed repair order belongs in the parcel, and the unit needs shock-proof packaging.