Airbag control unit with part number 6N0909603AC

What does the airbag control unit 6N0909603AC do?

The 6N0909603AC belongs to the restraint system (SRS) of Volkswagen as an airbag control unit. It checks the impact sensors, evaluates signals and decides within milliseconds which airbags and seatbelt pretensioners are triggered.

The system is monitored continuously, and faults appear via the airbag warning light. After an accident the unit stores crash data and locks.

The housing also carries the manufacturer's number Continental 5WK4137.

Why does the control unit 6N0909603AC fail?

In the 6N0909603AC, the most common cause after an accident is stored crash data, even if no airbag has been triggered. An ordinary diagnostic tool cannot erase this data. Other causes include ageing, cold solder joints, corrosion and voltage spikes.

Aged electronic components and cold solder joints can cause faults that have nothing to do with an accident. Only the fault memory shows which cause is present.

Moisture and corrosion at plug connections, as well as voltage spikes, for example from a weak battery or jump-starting, put additional strain on the electronics.

How can you tell that the 6N0909603AC is defective?

A defect in the 6N0909603AC shows itself through the airbag warning light in the instrument cluster, which lights up permanently or intermittently. A fault message in the instrument cluster also indicates it. In an emergency, the airbags and seatbelt pretensioners may then fail to trigger.

If the diagnostic tool does not connect to the control unit, or the fault memory cannot be cleared, that is also a sign. Have the indication checked promptly.

Which vehicles is the 6N0909603AC fitted in?

The 6N0909603AC is fitted in these vehicles: Volkswagen Polo 3 (6N) (1994-1999) and III 6N2 (1999-2001). Whether your model is among them can be seen from your car's papers.

The vehicles in detail:

• Volkswagen Polo 3 (6N) (1994-1999)
• Volkswagen Polo III 6N2 (1999-2001)

Comparing the part number on the label of the removed unit with this page only confirms that it is the right unit. The comparison says nothing about the cause. Therefore, have the fault memory read out before removal, because only the result 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 1C0 909 605 A, 1J0 909 603, 6N0 909 601, 6N0 909 603, 6N0909603E, 6Q0 909 601.

How does the repair of the 6N0909603AC work?

Have the fault memory read out and attach the log to the unit, then disconnect the battery and remove the 6N0909603AC. Then create a repair order online and send the unit in well packed.

Airbag24 tests the unit on the test bench, replaces defective components, erases stored crash data and carries out a function test. Afterwards your unit is returned to you.

Processing at Airbag24 usually takes 3–4 working days. 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 6N0909603AC get to Airbag24?

You send the 6N0909603AC as a parcel to Airbag24 or book a UPS collection for an extra charge. Airbag24 sends the unit back to you by UPS after the repair.

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