Airbag control unit with part number BFF7-57K30

What does the airbag control unit BFF7-57K30 do?

The airbag control unit BFF7-57K30 is the control unit of the restraint system (SRS) in Mazda vehicles. It evaluates the signals from the crash sensors and, in an accident, selects within milliseconds the airbags and seatbelt pretensioners that trigger. After an accident it stores crash data and locks itself.

During operation, it monitors the system continuously. If it detects a fault, the airbag warning light in the instrument cluster comes on. Only a repair lifts the lock.

Why does the control unit BFF7-57K30 fail?

The most common cause on the BFF7-57K30 is stored crash data from an accident, even without a deployed airbag. A standard diagnostic tool cannot erase it. Other causes are aged components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

Airbag24 removes this data during the repair. A standard diagnostic tool cannot do this.

The remaining causes concern ageing of the electronics and connection problems. Solder joints can go cold, moisture corrodes contacts, and voltage spikes from a jump start or a weak battery stress the electronics.

How can you tell that the BFF7-57K30 is defective?

A defect on the BFF7-57K30 shows up through the airbag warning light, a fault message or a fault memory that cannot be erased.

Typical signs:

• The airbag warning light in the instrument cluster stays on permanently or intermittently.
• The instrument cluster displays a fault message.
• The diagnostic tool gets no connection to the control unit.
• The fault memory cannot be erased.

As long as the defect exists, airbags and seatbelt pretensioners may not deploy in an emergency. A warning sign of this kind therefore calls for a prompt check.

Which vehicles is the BFF7-57K30 fitted in?

These vehicles are recorded for the BFF7-57K30: Mazda Mazda3 BL (2009-2011) and BL Facelift (2011-2013).

You will find the individual vehicles in the list:

• Mazda Mazda3 BL (2009-2011)
• Mazda Mazda3 BL Facelift (2011-2013)

Compare the number on the label of the removed unit with this page so that you have the correct unit. That does not answer whether it is defective. So have the fault memory read out first, because only this result shows whether the control unit or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 0 285 001 960, B39G-57K30, BCF1-57K30, BFB6-57-K30, BFD1-57K30.

How does the repair of the BFF7-57K30 work?

Have the fault memory read out first and enclose the log with the unit. Then disconnect the battery and only afterwards remove the control unit BFF7-57K30. Next, create a repair order online and pack the unit carefully for sending.

Airbag24 checks the control unit on the test bench, repairs defective components, erases the stored crash data and runs a function test. Processing at Airbag24 usually takes 3–4 working days. 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 BFF7-57K30 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 control unit BFF7-57K30 by UPS.

Enclose the printed repair order with the parcel and pack the unit shockproof.