Airbag control unit with part number A2048206685

What does the airbag control unit A2048206685 do?

The A2048206685 is the central control unit of the restraint system (SRS) of Mercedes-Benz. It processes the signals from the crash sensors and determines in a collision which airbags and seatbelt pretensioners are triggered.

The decision is made within milliseconds, and the unit monitors the system without interruption.

If it detects a fault, this appears via the airbag warning light. After an accident, it records crash data and locks itself.

Why does the control unit A2048206685 fail?

On the A2048206685, the most common cause of failure is the storage of crash data, even where no airbag has been triggered. Ageing electronics, cold solder joints, moisture at plug connections and voltage spikes are added to this.

Stored crash data cannot be removed with an ordinary diagnostic tool. Airbag24 erases it as part of the repair.

The electronics age, solder joints can go cold, and moisture and corrosion attack plug contacts.

Voltage spikes arise, for example, with a weak battery or when connecting jump leads.

How can you tell that the A2048206685 is defective?

A defect on the A2048206685 shows itself through the airbag warning light, through fault messages, or through a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then not trigger.

Typical signs are:

• airbag warning light that lights up permanently or intermittently
• fault message in the instrument cluster
• missing connection between the diagnostic tool and the control unit
• fault memory that cannot be cleared

Each of these signs justifies a check, even if the vehicle otherwise drives normally.

Which vehicles is the A2048206685 fitted in?

The A2048206685 is fitted in these vehicles: Mercedes-Benz C-Class S204 Estate (2007-2014), W204 Saloon (2007-2014) and C204 Coupé (2011-2015). This information names the vehicles to which this control unit is assigned.

The list follows as an overview.

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

Compare the part number on the label of the removed unit with this page; this ensures that it is the right unit. Also have the fault memory read out before removal, because only the log 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 2048709426, 5WK44740, A204 870 68 26, A204 901 26 04, A204 901 35 02, A2048208285.

How does the repair of the A2048206685 work?

First read out the fault memory and attach the log. Then disconnect the battery, remove the control unit and send it in well packed after the repair order has been created online. At Airbag24, processing usually takes 3–4 working days.

At Airbag24, the unit is checked first. Defective components are repaired as part of the repair, crash data is erased and a functional test is carried out.

The 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 A2048206685 get to Airbag24?

You send the A2048206685 to Airbag24 as a parcel or book a UPS collection for an extra charge. The return after the repair also runs by UPS.

Place the printed repair order in the parcel; the unit must be packed shock-proof.