Airbag control unit with part number DF73-57K30-E

What does the airbag control unit DF73-57K30-E do?

The airbag control unit DF73-57K30-E is the central control unit of the restraint system (SRS) for Mazda. It processes the signals from the crash sensors, decides in an accident within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the entire system continuously.

If it detects a fault, it displays this via the airbag warning light in the instrument cluster. The unit therefore works even when you are not looking, and logs faults in the fault memory.

After an accident it stores crash data and locks itself. Storing this data is part of the unit's basic function.

Why does the control unit DF73-57K30-E fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. Other causes that come into consideration are ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data cannot be cleared with an ordinary diagnostic tool. The system therefore continues to report the fault, even if nothing conspicuous can be noticed on the vehicle.

The remaining causes relate to age, environment and power supply. Moisture and corrosion attack the contacts, and cold solder joints lose their connection over time.

Voltage spikes, for example from a weak battery or a jump start, put additional strain on the electronics. Airbag24 clears the crash data during the repair.

How can you tell that the DF73-57K30-E is defective?

Typical signs are the airbag warning light in the instrument cluster lighting up permanently or intermittently, and an error message in the instrument cluster. In addition, the diagnostic tool has no connection to the control unit, and the fault memory cannot be cleared.

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

In an emergency, airbags and seatbelt pretensioners may therefore not be able to deploy. The message should be taken seriously and checked promptly.

Which vehicles is the DF73-57K30-E fitted in?

The control unit DF73-57K30-E is fitted in these vehicles: Mazda Mazda2 DE (2007-2010) and DE Facelift (2010-2014).

The overview lists the vehicles recorded for this part number.

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

(a) Compare the part number on the label of the removed unit with this page. This only shows that it is the correct unit. (b) Have the fault memory read out before removal, because only the 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 2S6T-14B056-EN, DF73-57K30B, GC1M-57-K30.

How does the repair of the DF73-57K30-E work?

First have the fault memory read out and enclose the log, then disconnect the battery and only afterwards remove the control unit. Then create the repair order online, before sending the unit in well packed. At Airbag24, checking, repairing and testing usually take 3–4 working days.

This sequence is mandatory for safety reasons and must not be swapped. It begins with the read-out and ends with removal.

Airbag24 checks the unit on the test bench, replaces defective components, clears stored crash data and carries out a function test. Your own unit is then 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 DF73-57K30-E get to Airbag24?

You send the control unit DF73-57K30-E as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends the unit back to you by UPS.

Remember to enclose the printed repair order, and make sure the unit is packed shock-resistant.