Airbag control unit with part number A4519013101

What does the airbag control unit A4519013101 do?

The airbag control unit A4519013101 is the central control unit of the restraint system (SRS) for Smart. It evaluates the crash sensors, decides in an accident within milliseconds on the triggering of airbags and seatbelt pretensioners, and monitors the system continuously.

The control unit shows faults via the airbag warning light in the instrument cluster. After an accident it stores crash data and locks itself. Only the repair lifts this lock.

Why does the control unit A4519013101 fail?

The most common cause of a failure of the A4519013101 is crash data stored after an accident, even if no airbag has deployed. Aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes are also possible causes.

A standard diagnostic tool cannot erase crash data. Airbag24 erases it during the repair.

The other causes develop over a longer period. Electronic components age, solder joints can go cold, and moisture or corrosion attack the connectors.

How can you tell that the A4519013101 is defective?

An airbag warning light in the instrument cluster that stays on permanently or intermittently is the clearest sign of a defect in the A4519013101. Fault messages, a missing connection to the diagnostic tool and a fault memory that cannot be cleared are further signs.

• The airbag warning light is on permanently or intermittently.
• A fault message appears in the instrument cluster.
• The diagnostic tool cannot establish a connection to the control unit.
• The fault memory cannot be cleared.

In an emergency, airbags and seatbelt pretensioners may then fail to deploy. The warning light reports the defect, so please take it seriously and have it checked promptly.

Which vehicles is the A4519013101 fitted in?

The control unit A4519013101 was fitted at Smart in several vehicles. It is installed in these vehicles: Smart Fortwo C451 (2007-2015).

The assigned models are listed here:

• Smart Fortwo C451 (2007-2015)

Compare the part number on the label of the removed unit with this page. This only confirms that you have the right unit. Also have the fault memory read out in advance. Only the result 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 A4519013101 work?

First have the fault memory read out and enclose the log with the unit. Then disconnect the battery and only afterwards remove the control unit A4519013101. Next, create a repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, replaces defective components, erases the stored crash data and carries out a function test. Airbag24 then sends your own unit back.

Processing at Airbag24 usually takes 3–4 working days. This time covers only 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 A4519013101 get to Airbag24?

You send the control unit A4519013101 as a parcel or, for an extra charge, book a UPS collection. After the repair, Airbag24 returns the unit by UPS.

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