Airbag control unit with part number A2218702893

What does the airbag control unit A2218702893 do?

The airbag control unit A2218702893 controls the restraint system (SRS) of Mercedes-Benz. It evaluates the signals from the crash sensors, decides within milliseconds in an accident whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously.

It indicates faults via the airbag warning light in the instrument cluster.

After an accident, the control unit stores crash data and locks itself. The housing also bears the manufacturer number Bosch 0285010424.

Why does the control unit A2218702893 fail?

The most common cause is crash data stored after an accident, even if no airbag has triggered; a normal diagnostic tool cannot erase it. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data remain in the unit, and a simple attempt to erase them does not solve the problem. That is why the fault memory cannot be reset.

The other causes can develop over time. Electronics age, solder joints can go cold, and moisture attacks the plugs.

Voltage spikes, such as those occurring with a weak battery or when starting with an external power source, can also cause damage.

How can you tell that the A2218702893 is defective?

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

If the control unit is faulty, the airbags and seatbelt pretensioners may not deploy in an emergency. The warning light indicates the defect, so act early rather than late.

Which vehicles is the A2218702893 fitted in?

The airbag control unit A2218702893 is fitted in these vehicles: Mercedes-Benz S-Class W221 Saloon (2005-2013). Whether it suits your own vehicle is shown by comparing it with this list.

You will find the assignment in detail in the overview.

• Mercedes-Benz S-Class W221 Saloon (2005-2013)

Comparing the part number on the label of the removed unit with this page only confirms that it is the right unit. Having the fault memory read out 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 2218200226, 2218704887, 285001896, 285001995, A0048201326, A2218200985.

How does the repair of the A2218702893 work?

First have the fault memory read out and attach the log. Then disconnect the battery and remove the control unit. Next, create a repair order online; testing, repair and function test at Airbag24 usually take 3–4 working days.

This sequence protects you when working on the vehicle, which is why it is fixed.

You send the well-packed unit to Airbag24, where it is checked on the test bench, repaired and tested with a function test. The stored crash data are deleted in the process. 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 A2218702893 get to Airbag24?

You send the control unit A2218702893 as a parcel, or book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

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