Airbag control unit with part number KA0H-57K30

What does the airbag control unit KA0H-57K30 do?

The airbag control unit KA0H-57K30 controls the restraint system (SRS) of Mazda. It evaluates the crash sensors, determines in an emergency which airbags and seatbelt pretensioners are triggered, and monitors the system continuously. After an accident it stores crash data and locks itself.

The evaluation takes place in fractions of a second, which is why the unit checks its components and connections constantly. If it detects a deviation, it records the finding in the fault memory.

The warning for you appears via the airbag warning light in the instrument cluster.

Why does the control unit KA0H-57K30 fail?

The most common cause is stored crash data after an accident, even without an airbag triggering, which a normal diagnostic tool cannot delete. In addition, there are ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

After an accident the unit writes crash data to its memory. These entries remain until a repair removes them, and a diagnostic tool from a workshop is not enough for that.

Ageing electronic components and cold solder joints lead to interruptions. Moisture and corrosion at plug connections distort signals, and voltage spikes, for example from a weak battery, stress the circuit.

How can you tell that the KA0H-57K30 is defective?

The airbag warning light lights up permanently or intermittently, a fault message appears in the instrument cluster, the diagnostic tool has no connection to the control unit, and the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then possibly not deploy.

• Airbag warning light stays on permanently
• Airbag warning light comes on only intermittently
• Fault message in the instrument cluster
• Diagnostic tool has no connection to the control unit
• Fault memory cannot be cleared

The warning light is the unit's feedback to you. You should take it seriously and have the finding clarified, rather than hoping the display will disappear.

Which vehicles is the KA0H-57K30 fitted in?

The KA0H-57K30 is fitted in these vehicles: Mazda CX-5 KE (2011-2015) and KE Facelift (2015-2017).

The list shows the vehicles stored 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, and you will know that it is the correct unit. Have the fault memory read out beforehand, because only this result shows whether the control unit is defective or whether a plug or cable is causing the fault.

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 KA0H-57K30 work?

Before removal, read out the fault memory and enclose the log. Disconnect the battery before you remove the control unit. Then create a repair order online and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, repairs defective components, deletes the stored crash data and carries out a functional test. Your own unit is then returned to you.

The order is for safety reasons. 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 KA0H-57K30 get to Airbag24?

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

Enclose the printed repair order and pack the unit shock-resistant.