Airbag control unit with part number BCKA-57K30D

What does the airbag control unit BCKA-57K30D do?

The airbag control unit BCKA-57K30D is the central control unit of the restraint system (SRS) of Mazda. It evaluates the signals from the crash sensors, decides in a crash within milliseconds about airbags and seatbelt pretensioners, and reports faults via the airbag warning light. After an accident it stores crash data and locks itself.

The unit monitors the restraint system continuously for as long as the vehicle has power. In doing so it checks sensors, wiring and trigger circuits.

In everyday use this monitoring is hardly noticed. It only becomes conspicuous when the control unit detects a fault.

Why does the control unit BCKA-57K30D fail?

The most common cause is crash data stored after an accident, even when no airbag has triggered. Other causes are aged components, moisture and corrosion at plug connections, and voltage spikes.

The device records crash data at the moment of impact. A normal diagnostic tool cannot erase them, so they remain in memory until they are deliberately removed.

The other causes at a glance:

• Aged electronic components that distort signals
• Cold solder joints in the circuit
• Moisture and corrosion at plug connections
• Voltage spikes, for example from a weak battery or jump-starting

How can you tell that the BCKA-57K30D is defective?

A defect in the BCKA-57K30D shows up through these signs:

• Airbag warning light in the instrument cluster lights up permanently or intermittently
• Fault message in the instrument cluster
• The diagnostic tool gets no connection to the control unit
• The fault memory cannot be cleared

With these signs airbags and seatbelt pretensioners may not trigger in an emergency. The warning light shows the finding as soon as the system detects it.

Which vehicles is the BCKA-57K30D fitted in?

The control unit BCKA-57K30D is fitted in these vehicles: Mazda Mazda3 BP (from 2019).

The overview shows the vehicles recorded for this part number:

• Mazda Mazda3 BP (from 2019)

Compare the part number on the label of your removed unit with this page. This only ensures that you have the right unit. Also have the fault memory read out before you remove the unit. Only this result shows whether the control unit itself is defective or whether a plug or 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-57K30D work?

First have the fault memory read out and attach the log. Then disconnect the battery and only afterwards remove the control unit BCKA-57K30D. Next create a repair order online and send in the well-packed unit.

Airbag24 checks the unit on the test bench, repairs defective components, erases the stored crash data and carries out a function test. Processing at Airbag24 usually takes 3–4 working days. Afterwards your own unit is 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 BCKA-57K30D get to Airbag24?

You send the control unit BCKA-57K30D in as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 returns it by UPS.

Put the printed repair order into the parcel and pack the unit shockproof.