Airbag control unit with part number KD47-57K30

What does the airbag control unit KD47-57K30 do?

The airbag control unit KD47-57K30 is the central control unit of the restraint system (SRS) for Mazda. It evaluates the signals from the crash sensors and determines within milliseconds in an accident which airbags and seatbelt pretensioners are triggered.

During operation it monitors all components of the system. If it detects a fault, it displays this via the airbag warning light in the instrument cluster.

After an accident the control unit stores crash data and locks itself. The lock is a fixed feature of this type of unit.

Why does the control unit KD47-57K30 fail?

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

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

The crash data remains stored in the control unit, and Airbag24 removes it during the repair. Reading it out with ordinary equipment changes nothing.

The other causes tend to develop gradually. Moisture and corrosion on contacts in particular only show up as a fault after a longer period.

How can you tell that the KD47-57K30 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, and an error message appears in the instrument cluster. In addition, the diagnostic tool cannot connect to the control unit, and the fault memory cannot be cleared.

You should take these signs seriously and have them checked promptly. In an emergency, the airbags and seatbelt pretensioners may not trigger.

If there is no contact with the diagnostic tool, the cause lies either in the control unit or in the wiring to it. Only the fault memory shows which.

Which vehicles is the KD47-57K30 fitted in?

The control unit KD47-57K30 is fitted in these vehicles: Mazda CX-5 KE (2011-2015) and KE Facelift (2015-2017).

The following vehicles are on record for this part number:

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

Compare the part number on the label of the removed unit with this page to confirm that you have the correct unit. It is also important to have the fault memory read out beforehand, 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 KA1C-57-K30A, KA1C-57K30, KD45-57K30B, KEAD 57K30 C, KR2757K30A.

How does the repair of the KD47-57K30 work?

First have the fault memory read out and attach the log. Then disconnect the battery before removing the control unit. Next, create a repair order online and send the unit in, well packed.

Airbag24 usually needs 3–4 working days for testing, repairing and checking. This time relates only to the work at Airbag24.

There the unit is checked on the test bench, defective components are repaired, the stored crash data is erased and a function test is carried out. 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 KD47-57K30 get to Airbag24?

You send the unit as a parcel or book UPS collection for an extra charge. After the repair it is sent back to you by UPS.

The printed repair order goes in the parcel. Pack the control unit shock-resistant.