Airbag control unit with part number KB7W-57K30A

What does the airbag control unit KB7W-57K30A do?

In the Mazda vehicle, the airbag control unit KB7W-57K30A forms the central control of the restraint system (SRS). It reads the crash sensors and decides in an accident, within milliseconds, which airbags and seatbelt pretensioners to trigger.

The unit monitors the system permanently and reports faults via the airbag warning light.

After an accident it creates crash data and locks itself. Only the repair lifts this lock.

Why does the control unit KB7W-57K30A fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. Aged electronic components, cold solder joints, moisture and corrosion at plug connections are also possible.

Crash data cannot be erased with a standard diagnostic tool. Airbag24 erases it during the repair, so no old entry remains in the memory.

Voltage spikes, for example from a weak battery or jump-starting, are among the other triggers. Which cause applies in an individual case is only shown by the test on the test bench.

How can you tell that the KB7W-57K30A is defective?

The airbag warning light lights up permanently or intermittently. In addition, a fault message may appear, the diagnostic tool receives no connection to the control unit, and the fault memory cannot be emptied.

In that case the airbags and seatbelt pretensioners may possibly not deploy in an emergency. You should therefore not ignore this warning.

Which vehicles is the KB7W-57K30A fitted in?

The control unit KB7W-57K30A is fitted in these vehicles: Mazda CX-5 KE (2011-2015) and KE Facelift (2015-2017).

You can see the assignment by vehicle in this list:

• Mazda CX-5 KE (2011-2015)
• Mazda CX-5 KE Facelift (2015-2017)

On the one hand, compare the part number on the label of the removed unit with this page; this only confirms that you have the correct unit. On the other hand, have the fault memory read out before removal, because only this log 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 KA1C-57-K30A, KA1C-57K30, KD45-57K30B, KEAD 57K30 C, KR2757K30A.

How does the repair of the KB7W-57K30A work?

First have the fault memory read out, enclose the log and then disconnect the battery. Only then remove the control unit KB7W-57K30A, create a repair order online and send in the well-packed unit. At Airbag24 processing usually takes 3–4 working days.

On the test bench the unit is examined, damaged parts are replaced, the crash data is erased and a function test is run. After completion, 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 KB7W-57K30A get to Airbag24?

You send a parcel with the control unit KB7W-57K30A to Airbag24, or you book a UPS collection for an extra charge. The return shipment by UPS follows the repair.

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