Airbag control unit with part number A4519011300

What does the airbag control unit A4519011300 do?

The airbag control unit A4519011300 coordinates the restraint system (SRS) for Smart. It evaluates the signals from the crash sensors, decides on airbags and seatbelt pretensioners in an accident, and monitors the system continuously. After an accident it stores crash data and locks itself.

It signals faults via the airbag warning light in the instrument cluster. Keeping an eye on this light helps you notice faults early.

The lock after an accident is part of the design of the system and affects the entire restraint system. Evaluation follows fixed specifications stored in the unit. These specifications define how the signals are assessed and remain unchanged during operation. A deviation from them is an indication of a fault.

Why does the control unit A4519011300 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered. Aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes are considered further causes.

Crash data cannot be deleted with a normal diagnostic tool. Airbag24 removes it during the repair.

The other causes concern the electronics and their connections. Solder joints can go cold, and moisture or corrosion on the contacts lead to malfunctions.

Voltage spikes, for example from a weak battery, can also overwhelm the electronics.

How can you tell that the A4519011300 is defective?

Typical signs are an airbag warning light that lights up permanently or intermittently, and a fault message in the instrument cluster. In addition the diagnostic tool finds no connection to the control unit.

• The airbag warning light lights up constantly or intermittently.
• A fault message appears in the instrument cluster.
• The diagnostic tool gets no connection to the control unit.

In an emergency, airbags and seatbelt pretensioners may then possibly fail to trigger. The light shows the defect, so you should take it seriously.

Which vehicles is the A4519011300 fitted in?

The control unit A4519011300 is fitted in these vehicles: Smart Fortwo C451 (2007-2015).

The following vehicles are on record for this control unit:

• Smart Fortwo C451 (2007-2015)

Match the part number on the label of the removed unit with this page so that you can be sure you have the correct unit. Also have the fault memory read out beforehand, because only that result 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 A4519011300 work?

You first have the fault memory read out and enclose the log. Then you disconnect the battery and only then remove the control unit A4519011300. Next you create a repair order online and send the unit.

Airbag24 checks it, repairs defective components, deletes stored crash data and carries out a function test. Processing at Airbag24 usually takes 3–4 working days.

Afterwards your own unit is returned 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 A4519011300 get to Airbag24?

You send the control unit A4519011300 as a parcel or you book a UPS collection for an extra charge. After the repair Airbag24 returns it by UPS.

Place the printed repair order in the parcel, and pack the unit so that it is shock-resistant.