Airbag control unit with part number D09H-57K30

What does the airbag control unit D09H-57K30 do?

The airbag control unit D09H-57K30 is the central control of the restraint system (SRS) in Mazda. It evaluates the crash sensors, determines within milliseconds in an accident the triggering of airbags and seatbelt pretensioners, and monitors the system continuously.

The unit indicates faults via the airbag warning light. After an accident it stores crash data and locks itself.

Why does the control unit D09H-57K30 fail?

The most common cause is crash data from an accident, even if no airbag has deployed. It cannot be erased with a standard diagnostic tool. Other causes are aged electronics, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

• Aged electronic components
• Cold solder joints
• Moisture and corrosion at plug connections
• Voltage spikes, for example from a weak battery or after a jump start

The crash data stays in memory even if the vehicle then drives normally again. Which of the other causes applies is determined by the test on the test bench.

How can you tell that the D09H-57K30 is defective?

A defect shows up as the airbag warning light in the instrument cluster, as a fault message, as a missing connection between the diagnostic tool and the control unit, and as a fault memory that cannot be cleared.

The warning light can stay on continuously or intermittently. If you see the light, have the cause checked promptly and do not ignore the indicator.

A defect in the control unit can, in an emergency, mean that airbags and seatbelt pretensioners may possibly not deploy.

Which vehicles is the D09H-57K30 fitted in?

The D09H-57K30 is fitted in these vehicles: Mazda Mazda2 DE (2007-2010) and DE Facelift (2010-2014).

The assignment lists these vehicles in detail:

• Mazda Mazda2 DE (2007-2010)
• Mazda Mazda2 DE Facelift (2010-2014)

Comparing the part number on the label of the removed unit with this page confirms that it is the right unit. The fault memory must, however, be read out beforehand, because only it shows whether the control unit is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 2S6T-14B056-EN, DF73-57K30B, GC1M-57-K30.

How does the repair of the D09H-57K30 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit. Then create a repair order online and pack the unit well for sending. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 tests the unit on the test bench, replaces defective components, erases the stored crash data and carries out a function test. 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 D09H-57K30 get to Airbag24?

You send the D09H-57K30 as a parcel, or you book a UPS collection for an extra charge. After the repair Airbag24 brings it back via UPS.

Put the printed repair order in the parcel, and pack the unit shockproof.