Airbag control unit with part number A1779009615

What does the airbag control unit A1779009615 do?

The airbag control unit A1779009615 is the central control unit of the restraint system (SRS) for Mercedes-Benz. It evaluates the signals from the crash sensors and decides within milliseconds in an accident which airbags and seatbelt pretensioners are triggered.

The manufacturer's part number Bosch 0285020951 is also printed on the housing.

The control unit monitors the system continuously and reports faults via the airbag warning light. After an accident it stores crash data and locks itself.

Why does the control unit A1779009615 fail?

The most common cause with the A1779009615 is crash data stored after an accident, even if no airbag has deployed. Other causes lie in the electronics themselves and at the connectors.

Crash data cannot be erased with a normal diagnostic tool. Airbag24 clears this data during the repair.

In detail, the following causes come into consideration:

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

How can you tell that the A1779009615 is defective?

A defect in the A1779009615 shows up as an airbag warning light that stays on permanently or intermittently, fault messages in the instrument cluster, no connection to the diagnostic tool, and a fault memory that cannot be cleared.

In that case, airbags and seatbelt pretensioners may not deploy in an emergency. These signs therefore show that the system is not fully operational.

The warning light is a signal that you should have checked promptly.

Which vehicles is the A1779009615 fitted in?

The airbag control unit A1779009615 is fitted in these vehicles: Mercedes-Benz A-Class W177 (from 2018).

The overview below shows which vehicles are recorded for this part number.

• Mercedes-Benz A-Class W177 (from 2018)

Comparing the part number on the label of the removed unit with this page only tells you whether it is the right unit. Whether the control unit is defective or a plug or cable is the cause can only be established by the fault log that you have read out beforehand.

For the same vehicles, we also repair control units with the part numbers 0 285 015 019, 0285020871, A 177 900 03 04, A1779027906, A2479013703, A2479018801.

How does the repair of the A1779009615 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit A1779009615. Next, create a repair order online and send in the unit, well packed.

Airbag24 checks the unit on the test bench, repairs defective components, clears the crash data and runs a function test. You then get your own unit back.

At Airbag24, processing usually takes 3–4 working days, and this period covers only checking, repairing and testing.

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 A1779009615 get to Airbag24?

The unit reaches Airbag24 either as a parcel that you send yourself, or via a UPS collection booked for an extra charge. After the repair, Airbag24 returns the control unit A1779009615 by UPS.

Put the printed repair order into the parcel and pack the unit shockproof.