Airbag control unit with part number 6Q0 909 605 T

What does the airbag control unit 6Q0 909 605 T do?

The airbag control unit 6Q0 909 605 T controls the restraint system (SRS) in the Volkswagen vehicle. It reads the sensor values, decides within milliseconds in the event of a crash whether airbags and seatbelt pretensioners are triggered, and checks the system permanently.

It monitors the system without interruption and reports faults via the airbag warning light in the instrument cluster. In this way, a failure is noticed in everyday driving.

After a crash the unit records crash data and locks itself.

Why does the control unit 6Q0 909 605 T fail?

The most common cause is crash data from an accident that remains in the unit, even if no airbag was deployed. In addition there are ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes from a weak battery or jump-starting.

Crash data stays in the memory after an accident, and a standard diagnostic tool cannot erase it. Airbag24 erases it as part of the repair.

The other causes develop gradually. Electronic components age, solder joints can become brittle, and moisture penetrates plug connections, where it causes corrosion. Brief voltage spikes, for example when starting with a weak battery, can also disrupt the control unit.

How can you tell that the 6Q0 909 605 T is defective?

Signs of a defect are an airbag warning light that lights up, a message in the instrument cluster, a diagnostic tool that cannot establish a connection, and a fault memory that you cannot reset. In an emergency, airbags and seatbelt pretensioners may not deploy.

These signs at a glance:

• Airbag warning light permanently or intermittently on
• Fault message in the instrument cluster
• Diagnostic tool does not find the control unit
• Fault memory remains

The warning light is one of the most important warnings the vehicle gives. When it lights up, the control unit has detected a deviation. A diagnostic tool can then check whether the fault lies in the control unit or outside it.

Which vehicles is the 6Q0 909 605 T fitted in?

The airbag control unit 6Q0 909 605 T is fitted in these vehicles: Volkswagen Polo 4 (9N) (2001-2005) and 4 (9N3) (2005-2009).

The following vehicles belong to this part number:

• Volkswagen Polo 4 (9N) (2001-2005)
• Volkswagen Polo 4 (9N3) (2005-2009)

Comparing the part number on the label of the removed unit with this page confirms that it is the right unit. Whether the control unit is defective is only answered by the fault memory. Have it read out beforehand for this reason.

For the same vehicles, we also repair control units with the part numbers 1C0 909 605 A, 1C0 909 605 F, 1C0 909 605 K, 6Q0 909 605S, 6Q0959654B.

How does the repair of the 6Q0 909 605 T work?

Have the fault memory read out and attach the log. Then disconnect the battery and remove the control unit. Create a repair order online and then send in the well-packed unit. Processing at Airbag24 usually takes 3–4 working days.

The sequence is binding for safety reasons. The removal only follows once the fault memory has been secured and the battery has been disconnected.

At Airbag24 the sent unit is checked on the test bench. A technician repairs defective components, erases 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 6Q0 909 605 T get to Airbag24?

You send the unit to Airbag24 as a parcel, or you book a UPS collection for an extra charge. The unit is returned to you by UPS after the repair.

The printed repair order belongs in the parcel. Pack the control unit shock-proof before it is sent.