Airbag control unit with part number A4518202585

What does the airbag control unit A4518202585 do?

The airbag control unit A4518202585 controls the restraint system (SRS) of Smart. It processes the data from the crash sensors, decides in an emergency within milliseconds whether airbags and seatbelt pretensioners are triggered, and monitors the system. After an accident it stores crash data and locks itself, and it shows faults via the airbag warning light.

The monitoring runs unnoticed in everyday use. Only a fault makes the unit visible to you, namely via the warning light in the instrument cluster.

Why does the control unit A4518202585 fail?

Crash data after an accident is the most common cause, even if no airbag has deployed. Other causes include ageing electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes.

A normal diagnostic tool cannot erase this crash data. Airbag24 carries out the erasure as part of the repair.

The other causes are related to ageing, moisture and electrical stress. A weak battery or connecting jump leads can produce voltage spikes.

How can you tell that the A4518202585 is defective?

The airbag warning light stays on permanently or intermittently, a fault message appears in the instrument cluster, the diagnostic tool gets no connection to the control unit, or the fault memory cannot be cleared. Each of these signs indicates a defect.

In an emergency, airbags and seatbelt pretensioners could fail to trigger. Do not wait for the problem to resolve itself.

Which vehicles is the A4518202585 fitted in?

The control unit A4518202585 is fitted in these vehicles: Smart Fortwo C451 (2007-2015). Your vehicle papers show whether your car is affected.

The list in detail:

• Smart Fortwo C451 (2007-2015)

Compare the part number on the label of the removed unit with this page. That establishes that you have the right unit. Having the fault memory read out beforehand, on the other hand, 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 A4518202585 work?

First have the fault memory read out and enclose the log. Then disconnect the battery, and only after that remove the control unit. Then create a repair order online and pack the unit well for shipping.

Airbag24 checks the unit on the test bench, repairs defective components, erases the crash data and carries out a function test. Testing, repairing and checking at Airbag24 usually take 3–4 working days. Afterwards your own unit goes 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 A4518202585 get to Airbag24?

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

Enclose the printed repair order and make sure the control unit is packed shock-proof.