Airbag control unit with part number BCKA-57K30C

What does the airbag control unit BCKA-57K30C do?

The airbag control unit BCKA-57K30C controls the restraint system (SRS) of Mazda. It evaluates the signals from the crash sensors and decides in an accident which airbags and seatbelt pretensioners are triggered. It works in milliseconds.

Between accidents it checks the components of the system. In the event of a fault, the airbag warning light in the instrument cluster lights up.

After an accident the unit stores crash data and locks itself. This fact is the core of what matters to you during the repair.

Why does the control unit BCKA-57K30C fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed; a normal diagnostic tool cannot remove it. Other causes are:

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

Crash data arises regardless of whether an airbag actually deploys. So if you have noticed no deployment, you should still check the cause.

How can you tell that the BCKA-57K30C is defective?

A defect shows up as the airbag warning light in the instrument cluster staying on permanently or intermittently, and as a fault message in the instrument cluster. A diagnostic tool with no connection to the control unit, or a fault memory that cannot be cleared, also points to a defect.

As long as the system is faulty, airbags and seatbelt pretensioners may not trigger in an emergency. The warning light is therefore the most important signal the vehicle gives.

When you start the vehicle, check whether the warning light comes on briefly and then goes out. If it stays on, a diagnosis is advisable.

Which vehicles is the BCKA-57K30C fitted in?

According to our current data, this assignment applies to Mazda. The control unit BCKA-57K30C is fitted in these vehicles: Mazda Mazda3 BP (from 2019).

The following overview lists the vehicles that are recorded with this number in our data.

• Mazda Mazda3 BP (from 2019)

Compare the part number on the label of the removed unit with this page, so you can be sure it is the right unit. Also have the fault memory read out, because only that result shows whether the control unit is defective or whether a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers BCKA-57-K30F, BCKA-57-K30G.

How does the repair of the BCKA-57K30C work?

First have the fault memory read out 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. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and runs a function test. The unit then 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 BCKA-57K30C get to Airbag24?

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

The printed repair order goes into the parcel. Pack the control unit shockproof before you hand it over.