Airbag control unit with part number 6N0909603F

What does the airbag control unit 6N0909603F do?

On Volkswagen the airbag control unit 6N0909603F is the central control unit of the restraint system (SRS). It reads the crash sensors, decides in a crash within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After an accident it stores crash data and locks itself.

If the unit detects a fault, it indicates this via the airbag warning light in the instrument cluster. Crash data, once stored, remain in the unit until they are deleted.

Why does the control unit 6N0909603F fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. They cannot be removed with a normal diagnostic tool. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Electronic components age, and solder joints change over time as well. Voltage spikes arise, for example, from a weak battery or a jump start, and can put a strain on the electronics.

How can you tell that the 6N0909603F is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, and an error message appears in the instrument cluster. The diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared. Airbags and seatbelt pretensioners may possibly fail to deploy in an emergency.

• Warning light in the instrument cluster, permanently or intermittently
• Error message in the instrument cluster
• No connection to the diagnostic tool
• Fault memory cannot be cleared

Note the messages and have the vehicle checked promptly.

Which vehicles is the 6N0909603F fitted in?

The airbag control unit 6N0909603F is fitted in these vehicles: Volkswagen Transporter T4 (1990-2003); Volkswagen Multivan T4 (1990-2003); Volkswagen Polo 3 (6N) (1994-1999) and III 6N2 (1999-2001); Volkswagen Caravelle T4 (1990-2003); Volkswagen California T4 (1990-2003).

You can find the vehicles recorded for this part number here:

• Volkswagen Transporter T4 (1990-2003)
• Volkswagen Multivan T4 (1990-2003)
• Volkswagen Polo 3 (6N) (1994-1999)
• Volkswagen Polo III 6N2 (1999-2001)
• Volkswagen Caravelle T4 (1990-2003)
• Volkswagen California T4 (1990-2003)

Comparing the part number on the label with this page only shows that it is the right unit. Having the fault memory read out before removing the control unit, however, shows whether the control unit is defective or 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, 1J0 909 603 AH, 1J0 909 603 BL, 1J0 909 603 E, 6N0 909 601.

How does the repair of the 6N0909603F work?

First have the fault memory read out and enclose the log, then disconnect the battery and only then remove the control unit. Next create a repair order online and send the unit in packed. Processing at Airbag24 takes 3–4 working days.

At the test bench Airbag24 checks the control unit. Defective components are replaced, crash data are deleted and the function is tested. After that your own unit is returned.

The order of the steps is there for your safety.

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 6N0909603F get to Airbag24?

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

The printed repair order goes with the parcel, and the unit should be packed shock-resistant.