Airbag control unit with part number 6N0909603A

What does the airbag control unit 6N0909603A do?

The airbag control unit 6N0909603A controls the restraint system (SRS) of Volkswagen and is responsible for which airbags and seatbelt pretensioners trigger in an accident. It evaluates the crash sensors and monitors the entire system continuously. It reports faults via the airbag warning light; after an accident it stores crash data and locks itself.

During driving, the unit constantly tests the connections to sensors and actuators. The crash sensors are also evaluated inside the unit itself.

Crash data is created regardless of whether the airbag actually triggered, and the unit locks itself afterwards.

Why does the control unit 6N0909603A fail?

The most common cause is crash data stored after an accident, even if no airbag has triggered; these data cannot be erased with a normal diagnostic tool. Further causes include aged electronic components, cold solder joints, moisture and corrosion on connectors, and voltage spikes, for example from a weak battery or a jump start.

Crash data is therefore the first thing to check during fault-finding.

The other causes mainly concern the hardware. Electronic components age, solder joints can go cold, and moisture and corrosion attack the connectors.

Voltage spikes from a weakened battery or a jump start additionally strain the circuits.

How can you tell that the 6N0909603A is defective?

The airbag warning light in the instrument cluster stays on constantly or intermittently, an error message appears in the instrument cluster, the diagnostic tool cannot reach the control unit, or the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

The warning light is the first and most important sign of a fault in the restraint system.

If it lights up, take it seriously and have the system checked. A light that comes on only at times also counts as one of these signs.

If the fault memory cannot be emptied despite an erase attempt, a cause is likely that needs checking.

Which vehicles is the 6N0909603A fitted in?

The airbag control unit 6N0909603A is fitted in these vehicles: Volkswagen Polo 3 (6N) (1994-1999) and III 6N2 (1999-2001). The vehicles are listed by make and model, where known.

These vehicles are assigned to the control unit:

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

Compare the part number on the label of the removed unit with this page. This only ensures that it is the correct unit. Also have the fault memory read out; only this result shows whether the control unit is defective or whether a connector or a 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 6N0909603A work?

First have the fault memory read out, disconnect the battery and remove the control unit before you create a repair order online and send the unit in. Processing at Airbag24 usually takes 3–4 working days. There the unit is checked, defective components are replaced, the stored crash data is erased and a function test is carried out before it is returned.

You enclose the fault memory log with the unit. This order serves safety.

The 3–4 working days apply solely to checking, repairing and testing at Airbag24.

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 6N0909603A get to Airbag24?

You send the unit in as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns the unit by UPS.

The printed repair order goes into the parcel, and the unit is packed shock-proof.