Airbag control unit with part number 3Q0959655BA

What does the airbag control unit 3Q0959655BA do?

The airbag control unit 3Q0959655BA controls the SRS restraint system of Volkswagen. It processes the crash sensor data, decides within milliseconds in an accident whether airbags and seatbelt pretensioners are triggered, and monitors the system permanently. It shows faults via the airbag warning light.

During operation the unit checks whether all connected components respond correctly. After an accident it stores crash data and locks itself.

Why does the control unit 3Q0959655BA fail?

Stored crash data is the most frequent cause after an accident; a standard diagnostic tool cannot erase it. Aged electronic components, cold solder joints, moisture and corrosion at connectors, and voltage spikes, for example from a weak battery or jump-starting, are further causes.

The crash data is held in the unit's memory and stays there even when the vehicle drives again afterwards. That is why it is checked first during fault-finding.

The other causes are of a general nature. Components age, solder joints can go cold, and moisture or corrosion disrupt the connection at plugs. Voltage spikes can damage components.

How can you tell that the 3Q0959655BA is defective?

A defect shows up as the airbag warning light in the instrument cluster staying on permanently or intermittently, and as an error message. A diagnostic tool that cannot connect to the control unit, and a fault memory that cannot be cleared, are further signs.

• Airbag warning light stays on permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool gets no connection to the control unit
• Fault memory cannot be cleared

In an emergency, airbags and seatbelt pretensioners may not deploy. Have such signs checked promptly.

Which vehicles is the 3Q0959655BA fitted in?

The control unit 3Q0959655BA is fitted in these vehicles: Volkswagen Passat B8 3G (2014-2023). You compare it with your car using the details in this section.

The following overview shows the assignment to this part number.

• Volkswagen Passat B8 3G (2014-2023)

Compare the part number on the label of the removed unit with this page. That only ensures it is the right unit. Have the fault memory read out beforehand, since only this result shows whether the control unit is defective or a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 3Q0 959 655 AE, 3Q0 959 655 AF, 3Q0 959 655 AP, 3Q0 959 655 BB, 3Q0 959 655 BK, 3Q0959655CL.

How does the repair of the 3Q0959655BA work?

Have the fault memory read out first and attach the log, then disconnect the battery and only then remove the control unit. Next, create a repair order online and send the unit well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, replaces defective components, deletes stored crash data and carries out a function test. Afterwards your own unit goes back 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 3Q0959655BA get to Airbag24?

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

Enclose the printed repair order and pack the unit shock-proof.