Airbag control unit with part number A2048208085

What does the airbag control unit A2048208085 do?

The airbag control unit A2048208085 controls the restraint system (SRS) in Mercedes-Benz. It evaluates the crash sensors, decides within milliseconds in an accident which airbags and seatbelt pretensioners are triggered, and checks the system continuously. Faults it finds are shown via the airbag warning light.

After an accident, the control unit stores crash data and is locked afterwards.

In everyday use the unit remains out of sight. It works in the background and only becomes noticeable when it detects a fault.

Why does the control unit A2048208085 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered. A normal diagnostic tool cannot erase it, but Airbag24 deletes it during the repair. Other causes include aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data is created by a registered event and stays in memory until it is removed. Only deletion removes it.

The other causes are the result of wear over the years, moisture on the contacts and electrical stress. A weak battery or a jump start can cause such stress.

How can you tell that the A2048208085 is defective?

The airbag warning light in the instrument cluster lights up constantly or intermittently, an error message appears, the diagnostic tool cannot connect to the control unit, or the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The warning light is the first and most visible sign. It shows the state of the system and should not be ignored.

If the diagnostic tool cannot be connected, that is a further sign of a fault. A targeted examination of the control unit then follows.

Which vehicles is the A2048208085 fitted in?

The control unit A2048208085 is fitted in these vehicles: Mercedes-Benz C-Class S204 Estate (2007-2014), W204 Saloon (2007-2014) and C204 Coupé (2011-2015).

The known vehicles at a glance:

• Mercedes-Benz C-Class S204 Estate (2007-2014)
• Mercedes-Benz C-Class W204 Saloon (2007-2014)
• Mercedes-Benz C-Class C204 Coupé (2011-2015)

You should compare the part number on the label of the removed unit with this page to make sure it is the correct unit. Only reading out the fault memory will show the actual condition. Only then will it become clear whether the control unit or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 2048709426, 5WK44740, A204 870 68 26, A204 901 26 04, A204 901 35 02, A2048208285.

How does the repair of the A2048208085 work?

Testing, repair and function testing at Airbag24 usually take 3–4 working days. Reading out, disconnecting and removing the unit are carried out by you beforehand, and these steps are not part of this time.

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. Next, create a repair order online and pack the unit carefully.

Airbag24 checks the unit on the test bench, replaces defective components, deletes the stored crash data and carries out a function test. Your own unit is then 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 A2048208085 get to Airbag24?

The unit reaches Airbag24 by parcel, or it is collected by UPS for an extra charge. UPS brings it back to you.

Put the printed repair order into the consignment, and the packaging must be shock-resistant.