Airbag control unit with part number KD47-57K30B

What does the airbag control unit KD47-57K30B do?

The airbag control unit KD47-57K30B controls the restraint system (SRS) of Mazda. Using the crash sensors, it detects an accident and decides within milliseconds whether airbags and seatbelt pretensioners are triggered.

In addition, it checks the entire system continuously. Faults found are indicated via the airbag warning light in the instrument cluster.

After a crash, it stores crash data and locks itself.

Why does the control unit KD47-57K30B fail?

The most common cause in the KD47-57K30B is crash data from an accident that stays in the memory even if no airbag has deployed. Other causes include ageing components, cold solder joints, moisture and corrosion at plugs, and voltage spikes.

Crash data cannot be erased with an ordinary diagnostic tool. Airbag24 removes it during the repair.

Ageing electronic components and cold solder joints create unreliable connections that make themselves felt during operation.

Moisture and corrosion at plug connections have a similar effect. Voltage spikes, for example from a weak battery or from a jump start, add further strain to the electronics.

How can you tell that the KD47-57K30B is defective?

A defect in the KD47-57K30B shows up as the airbag warning light, an error message in the instrument cluster, a missing connection to the diagnostic tool or a fault memory that cannot be cleared.

The following signs indicate a defect:

• Warning light on permanently or intermittently
• Error message in the instrument cluster
• No contact between the diagnostic tool and the control unit
• Fault memory cannot be cleared

In such a case, airbags and seatbelt pretensioners may not trigger in an emergency. The warning light makes the fault visible, so a prompt check is worthwhile.

Which vehicles is the KD47-57K30B fitted in?

The KD47-57K30B is fitted in these vehicles: Mazda CX-5 KE (2011-2015) and KE Facelift (2015-2017).

This overview lists the vehicles on record for this part number.

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

Check the part number on the label of the removed control unit against this page. This only tells you that it is the matching control 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 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 KD47-57K30B work?

First, have the fault memory read out and enclose the printout with the unit. Then disconnect the battery, and only then remove the KD47-57K30B. Next, create a repair order online and pack the unit well for sending.

At Airbag24, the unit is checked on the test bench, defective components are replaced, the crash data is erased and a function test is run. Afterwards, your own unit goes back to you.

For this work, you can generally expect 3–4 working days at Airbag24. Reading out, removal and shipping are not included.

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 KD47-57K30B get to Airbag24?

You can send the KD47-57K30B as a parcel or book a UPS collection for an extra charge. After the repair, UPS brings the unit back to you.

Include the printed repair order in the parcel. Pack the control unit shockproof.