Airbag control unit with part number 1J0 909 608 BA

What does the airbag control unit 1J0 909 608 BA do?

The airbag control unit 1J0 909 608 BA controls the restraint system (SRS) in the Volkswagen. It processes the signals from the crash sensors and decides within milliseconds in an accident which airbags and seatbelt pretensioners are triggered.

The housing also carries the manufacturer part number Continental 5WK4154. In addition, the unit continuously monitors the entire system and reports faults via the airbag warning light in the instrument cluster.

After an accident it secures the crash data and then locks itself.

Why does the control unit 1J0 909 608 BA fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. Other causes include aged components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes from a weak battery or jump-starting.

Crash data cannot be erased with a standard diagnostic tool. Airbag24 therefore removes it during the repair.

Other causes at a glance:

• wear of electronic components
• cold solder joints
• moisture in plug connections with corrosion
• voltage spikes, for example from jump-starting

How can you tell that the 1J0 909 608 BA is defective?

A defect in the 1J0 909 608 BA is indicated by the airbag warning light in the instrument cluster and by fault messages there. Further signs are problems with diagnosis, when the diagnostic tool cannot establish a connection or the fault memory cannot be cleared.

• airbag warning light stays on permanently
• airbag warning light comes on intermittently
• fault message in the instrument cluster
• diagnostic tool gets no connection to the control unit
• fault memory cannot be cleared

With these signs, it cannot be ruled out that the airbags and seatbelt pretensioners will not deploy in an emergency. Please have the system checked promptly.

Which vehicles is the 1J0 909 608 BA fitted in?

The 1J0 909 608 BA is fitted in these vehicles: Volkswagen Golf 4 (1J); Volkswagen Golf GTI Mk4; Volkswagen Golf Variant 4 (1J5).

The assignment by model and year of construction can be found in the overview.

• Volkswagen Golf 4 (1J)
• Volkswagen Golf GTI Mk4
• Volkswagen Golf Variant 4 (1J5)

Matching the part number on the label of the removed unit with this page only confirms the identity of the unit. Please have the fault memory read out before removal, because only this log shows whether the control unit itself is defective or a plug or cable is behind the fault.

For the same vehicles, we also repair control units with the part numbers 0261207190, 1C0 909 605 A, 1C0 909 605 F, 1J0 909 603 AN, 1J0 909 605 A, 1J0 909 609.

How does the repair of the 1J0 909 608 BA work?

Start by having the fault memory read out and enclose the log with the unit. Then disconnect the battery and only then remove the control unit. Finally, create the repair order online and send the packed unit in.

At Airbag24 the control unit is tested, defective components are repaired, the stored crash data is erased and a function test concludes the work. The unit is then returned to you.

Processing at Airbag24 takes 3–4 working days; this time covers only testing, repair and function testing. 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 1J0 909 608 BA get to Airbag24?

You can either send the unit to Airbag24 as a parcel, or book a UPS collection for an extra charge. After the repair, the return shipment is made by UPS.

The printed repair order belongs in the parcel, and the unit must be packed shock-proof.