Airbag control unit with part number A2139019011

What does the airbag control unit A2139019011 do?

The airbag control unit A2139019011 controls the restraint system (SRS) in Mercedes-Benz vehicles. It evaluates 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, which is located in the instrument cluster.

After an accident, the unit stores crash data and locks itself.

Why does the control unit A2139019011 fail?

The most common cause is crash data stored after an accident, even without a deployed airbag. Aging and contact problems are also prominent, such as aged components, cold solder joints, moisture and corrosion, and voltage spikes.

Crash data cannot be erased with a normal diagnostic tool.

• aged electronic components
• cold solder joints
• moisture and corrosion on plug connections
• voltage spikes, for example from a weak battery or a jump-start

How can you tell that the A2139019011 is defective?

A defect shows up as the airbag warning light, which lights up permanently or intermittently. In addition there may be a fault message in the instrument cluster, no connection to the diagnostic tool, and a fault memory that cannot be cleared.

The warning light is a signal from the vehicle itself. In an emergency, the airbags and seatbelt pretensioners may fail to deploy, so please have the finding checked promptly.

Which vehicles is the A2139019011 fitted in?

Start by checking your vehicle documents. The control unit A2139019011 is fitted in these vehicles: Mercedes-Benz E-Class S213 Estate (2016-2023) and W213 Saloon (2016-2023).

Next follows the list of vehicles that Airbag24 has linked to this number.

• Mercedes-Benz E-Class S213 Estate (2016-2023)
• Mercedes-Benz E-Class W213 Saloon (2016-2023)

On the one hand, compare the part number on the label of the removed unit with this page; this only confirms that it is the right unit. On the other hand, have the fault memory read out beforehand, because only this 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 A213 900 46 25, A213 900 88 22, A213 900 88 28, A2139004325, A2139004425, A2139007005.

How does the repair of the A2139019011 work?

First have the fault memory read out, disconnect the battery and only then remove the control unit; attach the log to the unit. Then create the repair order online and send the unit. Airbag24 checks, repairs and tests it within 3–4 working days as a rule.

This sequence protects you when working on the airbag system, so please follow it.

At Airbag24, the control unit is examined on the test bench, defective components are replaced, and stored crash data is deleted. Finally, a function test is carried out, and then your 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 A2139019011 get to Airbag24?

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

The printed repair order belongs in the parcel. Pack the unit shockproof.