Airbag control unit with part number 1K0909605S

What does the airbag control unit 1K0909605S do?

The airbag control unit 1K0909605S is the central control unit of the restraint system (SRS) for Seat and Skoda. It evaluates the signals from the crash sensors, decides within milliseconds in an accident whether airbags and seatbelt pretensioners are triggered, and reports faults via the airbag warning light.

In everyday use the unit monitors the entire system without interruption. It continuously checks whether all connected components deliver signals and work plausibly, and if there is a deviation, it records an entry in the fault memory.

After an accident the control unit stores crash data and locks itself. Any later diagnosis of the unit will recognise this state.

Why does the control unit 1K0909605S fail?

The most common cause is crash data stored in the unit after an accident, even if no airbag has deployed. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

Crash data cannot be erased with a normal diagnostic tool. At Airbag24 it is erased as part of the repair.

The other causes concern the electronics themselves. Components age with time, solder joints can go cold, and moisture or corrosion at the connectors disrupts the contact. Voltage spikes in the vehicle electrical system can also affect the electronics.

How can you tell that the 1K0909605S is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, a fault message appears in the instrument cluster, the diagnostic tool gets no connection to the control unit, and the fault memory cannot be cleared. In this state airbags and seatbelt pretensioners may not deploy in an emergency.

The warning light is the notice you will notice first, and it deserves attention even if the vehicle can still be driven normally.

A failed connection to the diagnostic tool indicates that something is wrong in the control unit or at its connections. Which of the two possibilities applies only becomes clear when the fault memory is evaluated.

Which vehicles is the 1K0909605S fitted in?

Check whether your vehicle is included. The airbag control unit 1K0909605S is fitted in these vehicles: Seat Toledo 3 [5P] (2004-2009); Seat Altea 1 Facelift (2009-2015) and 1 (2004-2009); Skoda Octavia 2 [1Z] (2004-2012) and 2 [1Z] Facelift (2009-2013).

More specifically, these are the vehicles concerned. The list shows the assignment stored in our database for this number.

• Seat Toledo 3 [5P] (2004-2009)
• Seat Altea 1 Facelift (2009-2015)
• Seat Altea 1 (2004-2009)
• Skoda Octavia 2 [1Z] (2004-2012)
• Skoda Octavia 2 [1Z] Facelift (2009-2013)

Before you remove the unit, these steps are worthwhile. Compare the part number on the label of the removed unit with this page; that only confirms that it is the right unit. Also have the fault memory read out beforehand, because this log shows whether the control unit is defective or whether a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers 1K0 909 605 T, 1K0909605AA, 1K0909605M, 1K0909605R.

How does the repair of the 1K0909605S work?

First have the fault memory read out and attach the log, then disconnect the battery and only afterwards remove the control unit. Then create a repair order online and send the unit in well packed. Airbag24 checks it on the test bench, replaces defective components, erases the stored crash data and carries out a function test.

Processing at Airbag24 usually takes 3–4 working days. This time applies only to checking, repairing and testing at Airbag24; 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 1K0909605S get to Airbag24?

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

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