Airbag control unit with part number A4519017700

What does the airbag control unit A4519017700 do?

The airbag control unit A4519017700 coordinates the restraint system (SRS) for Smart. It evaluates the crash sensors, determines within milliseconds in an accident which airbags and seatbelt pretensioners are triggered, and monitors the system continuously.

It reports faults via the airbag warning light. After an accident the unit stores crash data and locks itself.

Why does the control unit A4519017700 fail?

It most often fails because of crash data stored after an accident, even without a deployed airbag. Other causes are the ageing of the electronics, cold solder joints, moisture and voltage spikes.

A normal diagnostic tool cannot remove crash data. Airbag24 deletes it during the repair.

Other triggers can also play a role:

• ageing electronic components
• cold solder joints
• moisture and corrosion at plugs
• voltage spikes, for example from a jump start or a weak battery

How can you tell that the A4519017700 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently. In addition an error message appears, the diagnostic tool cannot find the control unit, and the fault memory cannot be cleared.

The warning light is the most visible sign of a fault in the restraint system. If it lights up, have the system checked promptly.

In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

Which vehicles is the A4519017700 fitted in?

The control unit A4519017700 is fitted in these vehicles: Smart Fortwo C451 (2007-2015). Please check before removal whether your model is among them.

These vehicles are on record:

• Smart Fortwo C451 (2007-2015)

First, compare the part number on the label of the removed unit with this page. That shows only that you have the right unit. Second, have the fault memory read out beforehand, because only it shows whether the control unit 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 A4519017700 work?

First have the fault memory read out and enclose the log. Then disconnect the battery, remove the control unit and create the repair order online. Processing at Airbag24 usually takes 3–4 working days.

Pack the unit well and send it in. Airbag24 checks it on the test bench, repairs defective components, deletes the crash data and carries out a function test.

Afterwards your own unit comes 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 A4519017700 get to Airbag24?

You can send the unit in as a parcel, or book a UPS collection for an extra charge. After the repair it is returned to you by UPS.

Put the printed repair order in the parcel; the control unit must be packed shock-proof.