Airbag control unit with part number A4519012001

What does the airbag control unit A4519012001 do?

The airbag control unit A4519012001 is the central control unit of the restraint system (SRS) for Smart. It processes the signals from the crash sensors, decides in an accident within milliseconds whether airbags and seatbelt pretensioners are triggered, and reports faults via the airbag warning light.

The system is monitored continuously. This covers the sensors, the airbags and the seatbelt pretensioners together with their wiring.

After an accident the unit stores crash data and locks itself.

Why does the control unit A4519012001 fail?

The most common cause is crash data from an accident, even if no airbag was triggered. A normal diagnostic tool does not erase it. Other causes are ageing components, cold solder joints, moisture or corrosion at plug connectors, and voltage spikes.

Airbag24 removes the crash data during the repair. That is part of the regular processing.

The further causes in detail:

• Electronic components age over time.
• Solder joints on the circuit board can go cold.
• Moisture and corrosion attack plug connectors.
• Voltage spikes, for example from a weak battery or jump-starting, stress the components.

How can you tell that the A4519012001 is defective?

A defect in the A4519012001 shows up as the airbag warning light in the instrument cluster staying on permanently or intermittently. Added to this are a fault message there, a diagnostic tool without a connection to the control unit, and a fault memory that cannot be cleared.

In such a fault, the airbags and seatbelt pretensioners may fail to trigger in an emergency. Take the warning seriously, even if the vehicle seems unremarkable in everyday driving.

Please have the finding checked promptly.

Which vehicles is the A4519012001 fitted in?

The assignment depends on the part number A4519012001. The control unit A4519012001 is fitted in these vehicles: Smart Fortwo C451 (2007-2015).

The overview contains the vehicles recorded for this part number.

• Smart Fortwo C451 (2007-2015)

Compare the part number on the label of the removed unit with this page, so you can be sure you have the right unit. Also have the fault memory read out beforehand, as only that shows whether the control unit itself is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers A451 820 24 85, A4518201585/001, A4518202285, A4518202485/002, A4519011300Q02.

How does the repair of the A4519012001 work?

Processing at Airbag24 usually takes 3–4 working days. Beforehand have the fault memory read out and enclose the printout. Then disconnect the battery and only afterwards remove the control unit. Then create a repair order online and send in the carefully packed unit.

Airbag24 checks the unit on the test bench, repairs defective components, erases the stored crash data and carries out a function test. The unit then goes back to you.

This time applies only to checking, repairing and testing at Airbag24.

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 A4519012001 get to Airbag24?

You send the control unit A4519012001 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

Put the printed repair order in the parcel and pack the unit shock-proof.