Airbag control unit with part number 2Q0 959 655 AD

What does the airbag control unit 2Q0 959 655 AD do?

The airbag control unit 2Q0 959 655 AD is the central control unit of the restraint system (SRS) in the Audi. It evaluates the signals from the crash sensors, decides within milliseconds on airbags and seatbelt pretensioners, and monitors the system continuously.

The crash sensors continuously supply the control unit with measured values, from which it assesses the situation. This evaluation is the basis for deciding which restraint elements become active.

The manufacturer's number Bosch 0285014559 is additionally printed on the housing. The unit reports faults via the airbag warning light, and after an accident it creates crash data and locks itself.

Why does the control unit 2Q0 959 655 AD fail?

Stored crash data is the most common cause with the 2Q0 959 655 AD, even if no airbag has triggered; other causes are aged components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

A normal diagnostic tool cannot erase the crash data. Airbag24 takes on this task during the repair, as a complete part of the testing.

Aged electronic components are another possible reason. Solder joints can go cold, and moisture or corrosion at plug connections disturb the contact.

Voltage spikes, for example from a weak battery or a jump start, can stress the electronics and trigger faults.

How can you tell that the 2Q0 959 655 AD is defective?

You can recognise a defect in the 2Q0 959 655 AD by the airbag warning light in the instrument cluster, which lights up constantly or intermittently; in addition there are error messages, no connection to the diagnostic tool and a fault memory that cannot be cleared.

• Airbag warning light is on constantly or intermittently.
• Error message in the instrument cluster.
• The diagnostic tool has no connection to the control unit.
• The fault memory cannot be cleared.

In an emergency, airbags and seatbelt pretensioners may then not trigger. Therefore have the findings checked promptly.

Which vehicles is the 2Q0 959 655 AD fitted in?

The control unit 2Q0 959 655 AD is fitted in these vehicles: Audi A1 GB (from 2018).

Here follows the overview of the vehicles with this part number.

• Audi A1 GB (from 2018)

Beforehand, compare the part number on the label of the removed unit with this page; this only confirms that it is the right unit. Also have the fault memory read out, because the log is what shows whether the control unit is defective or whether a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 2Q0 959 655 AK, 2Q0959655AC.

How does the repair of the 2Q0 959 655 AD work?

First read out the fault memory of the 2Q0 959 655 AD and enclose the log. Then disconnect the battery, and only then remove the control unit; afterwards create a repair order online and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 tests the unit on the test bench, replaces defective components, erases the stored crash data and carries out a functional test. The unit then goes back 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 2Q0 959 655 AD get to Airbag24?

The 2Q0 959 655 AD reaches Airbag24 as a parcel or via a UPS collection booked for an extra charge; after the repair Airbag24 sends it back by UPS.

Place the printed repair order in the parcel and pack the unit shockproof.