Airbag control unit with part number A4519010801

What does the airbag control unit A4519010801 do?

The airbag control unit A4519010801 is the central control unit of the restraint system (SRS) for Smart. It checks the signals of the crash sensors, decides within milliseconds in an emergency which airbags and seatbelt pretensioners trigger, and monitors the system continuously. After an accident, it stores crash data and locks itself; faults are shown via the airbag warning light.

The system is designed to run for the entire life of the vehicle. In normal operation, the control unit therefore goes unnoticed.

Why does the control unit A4519010801 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered. Aged electronic components, corrosion on connectors and voltage spikes can also be involved.

Crash data stays in the memory until it is deliberately removed. An ordinary diagnostic tool cannot delete this data, and Airbag24 removes it during the repair.

The other causes tend to develop over time: components age, solder joints can go cold, and moisture finds its way to plugs. Voltage spikes arise, for example, with a weak battery or when a jump start is connected.

Several causes can occur together, so a clear attribution without an inspection is not possible.

How can you tell that the A4519010801 is defective?

An airbag warning light in the instrument cluster that burns permanently or intermittently is the clearest sign of a defect. Also noticeable are an error message in the instrument cluster, a diagnostic tool without connection and a fault memory that cannot be cleared.

• Airbag warning light burns permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool cannot find the control unit
• Fault memory cannot be cleared

If you notice any of these signs, have the system checked promptly. Airbags and seatbelt pretensioners may possibly not trigger in an emergency.

Which vehicles is the A4519010801 fitted in?

The control unit A4519010801 is fitted in these vehicles: Smart Fortwo C451 (2007-2015). Your vehicle documents show whether your car is affected.

The following is the list of vehicles:

• Smart Fortwo C451 (2007-2015)

Comparing the part number on the label of the removed unit only answers whether it is the correct unit. Have the fault memory read out in addition before removal, because only this log 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 A451 820 24 85, A4518201585/001, A4518202285, A4518202485/002, A4519011300Q02.

How does the repair of the A4519010801 work?

Have the fault memory read out first and attach the log. Then disconnect the battery and only afterwards remove the control unit. Then create a repair order online and send the unit well packed. Airbag24 checks it on the test bench, repairs defective components, deletes the crash data and carries out a function test.

For checking, repairing and testing at Airbag24, 3–4 working days are generally planned, after which your own unit is returned.

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 A4519010801 get to Airbag24?

You can send the unit as a parcel or book a UPS collection for an extra charge. The return after the repair is also made by UPS.

Print out the repair order and enclose it. Pack the control unit so that it arrives safely and shock-proof.