Airbag control unit with part number 5WK43123

What does the airbag control unit 5WK43123 do?

The airbag control unit 5WK43123 is the central controller of the restraint system (SRS) in Skoda. It evaluates the signals from the crash sensors, determines within milliseconds in a crash which airbags and seatbelt pretensioners are triggered, and monitors the entire system. It reports faults via the airbag warning light.

The crash sensors constantly supply measured values to the unit, and it also checks the wiring to the airbags and seatbelt pretensioners. This monitoring runs in the background while you drive.

After a crash, the control unit stores crash data and locks itself.

Why does the control unit 5WK43123 fail?

Stored crash data is the most common cause, even if no airbag was deployed in the incident. Other possible causes include aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes.

Crash data cannot be erased with a standard diagnostic tool, so the fault remains. Airbag24 erases the crash data during the repair.

Other causes at a glance:

• aged electronic components
• cold solder joints
• moisture and corrosion at plug connectors
• voltage spikes, for example from a weak battery or a jump start

How can you tell that the 5WK43123 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, and a fault message appears in the instrument cluster. In addition, the diagnostic tool cannot connect to the control unit and the fault memory cannot be cleared; in an emergency, airbags and seatbelt pretensioners may then fail to deploy.

If the warning light stays on after the ignition is switched on, have the system checked promptly. It gives the clearest indication of a problem.

A fault message alone does not prove that the control unit is defective. Evaluating the fault memory shows whether the unit itself is affected or a wire or connector.

Which vehicles is the 5WK43123 fitted in?

The control unit 5WK43123 is fitted in these vehicles: Skoda Fabia 1 [6Y] Facelift (2004-2007) and 1 [6Y] (1999-2004). Matching the part number shows you whether it is the right unit.

The vehicles registered for this part number are shown in the overview below.

• Skoda Fabia 1 [6Y] Facelift (2004-2007)
• Skoda Fabia 1 [6Y] (1999-2004)

First check the part number on the label of the removed unit against this page. Also have the fault memory read out before you remove anything, because only the 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 1C0 909 601, 1C0 909 601 A, 1C0 909 605 H, 1C0 909 605 K, 1C0909601C, 5WK43120.

How does the repair of the 5WK43123 work?

For the control unit 5WK43123, first have the fault memory read out and attach the log, then disconnect the battery; after that, remove the unit. Then create a repair order online and send the unit in packed. Processing at Airbag24 usually takes 3–4 working days.

This sequence is mandatory, because safety comes first. Removal only begins once the battery has been disconnected.

Airbag24 tests the unit on the test bench, repairs defective components, erases the stored crash data and carries out a function test. Only then is your own unit returned 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 5WK43123 get to Airbag24?

You send the control unit 5WK43123 as a parcel or book a UPS collection for an extra charge. Airbag24 sends the unit back to you by UPS after the repair.

Include the printed repair order in the parcel. Pack the unit shockproof before it is sent.