Airbag control unit with part number A1698207826

What does the airbag control unit A1698207826 do?

The airbag control unit A1698207826 is the central control unit of the restraint system (SRS) for Mercedes-Benz. It evaluates the signals from the crash sensors, decides in a crash within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the system during operation.

If the unit detects a fault, it reports it via the airbag warning light in the instrument cluster, so that the driver recognises the malfunction.

After an accident, the control unit stores crash data and locks itself. This fact describes the property of the unit; no further explanation is needed here.

Why does the control unit A1698207826 fail?

The most common cause is crash data stored after an accident, even without a triggered airbag; a normal diagnostic tool cannot erase it. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data is created on impact and remains in the unit, even if the accident was minor. A standard diagnostic tool cannot reach this data.

Electronic components age, and solder joints can go cold. As a result, the function of the control unit gradually deteriorates.

Moisture and corrosion at the plug connections disturb the electrical contact. Voltage spikes, for example from a weak battery or jump-starting, put additional strain on the circuitry.

How can you tell that the A1698207826 is defective?

A defect in the A1698207826 shows when the airbag warning light in the instrument cluster stays on permanently or intermittently. A fault message in the instrument cluster, a missing connection to the diagnostic tool and a fault memory that cannot be cleared may also appear. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

Typical signs are summarised in this list:

• The airbag warning light stays on permanently or flickers.
• The instrument cluster displays a fault message.
• The diagnostic tool receives no connection to the control unit.
• The fault memory cannot be cleared.

Each of these signs justifies a specialist examination, because the system must work in an emergency.

Which vehicles is the A1698207826 fitted in?

The control unit A1698207826 is fitted in these vehicles: Mercedes-Benz B-Class W245 (2005-2011); Mercedes-Benz A-Class W169 (2004-2012). Whether your car is among them is shown by comparing it with the details in the registration document.

You will find the vehicles in detail here:

• Mercedes-Benz B-Class W245 (2005-2011)
• Mercedes-Benz A-Class W169 (2004-2012)

Before removing the unit, there are two checks worth making. (a) Comparing the part number on the label of the unit with this page only ensures that it is the right unit. (b) Having the fault memory read out beforehand 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 A1698201326, A1698202726, A1698204085, A1698206626, A1698206726, A1698207726.

How does the repair of the A1698207826 work?

First have the fault memory read out and attach the log. Then disconnect the battery, only then remove the control unit, create a repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, replaces defective components, erases stored crash data and carries out a function test. Afterwards, the unit goes back to you.

Processing at Airbag24 usually takes 3–4 working days. This period applies only to checking, repairing and testing in the house.

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 A1698207826 get to Airbag24?

You send the control unit A1698207826 as a parcel, or book a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back to you by UPS.

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