Airbag control unit with part number D09J-57K30A

What does the airbag control unit D09J-57K30A do?

The airbag control unit D09J-57K30A is the central control unit of the restraint system (SRS) of Mazda. It evaluates the crash sensors, decides in an accident within milliseconds about triggering airbags and seatbelt pretensioners, and monitors the system continuously.

If the unit detects a fault, it shows it via the airbag warning light in the instrument cluster. Monitoring covers airbags, seatbelt pretensioners, sensors and the wiring in between.

After an accident, the control unit stores crash data and locks itself.

Why does the control unit D09J-57K30A fail?

The most common cause is crash data stored after an accident, even if no airbag has been triggered. A standard diagnostic tool cannot delete it. Other causes are aged electronic components, cold solder joints, moisture and corrosion on connectors, and voltage spikes, for example from a weak battery or jump-starting.

Airbag24 deletes the crash data during the repair. This step is part of the regular processing of the unit.

Electronics age, solder joints can become cold over time, and moisture and corrosion attack connectors.

How can you tell that the D09J-57K30A is defective?

A defect on the D09J-57K30A shows as the airbag warning light staying on permanently or intermittently, and as a fault message in the instrument cluster. In addition, the diagnostic tool cannot establish a connection to the control unit, and the fault memory cannot be cleared.

• The airbag warning light stays on permanently or intermittently.
• A fault message appears in the instrument cluster.
• The diagnostic tool does not connect to the control unit.
• The fault memory remains even after an attempt to clear it.

In such a fault, airbags and seatbelt pretensioners may possibly not trigger in an emergency. Take each of these indications seriously.

Which vehicles is the D09J-57K30A fitted in?

The control unit D09J-57K30A is fitted in these vehicles: Mazda Mazda2 DE (2007-2010) and DE Facelift (2010-2014). The part number on the unit is decisive for the assignment.

The following list shows the vehicles recorded for this part number.

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

Compare the part number on the label of the removed unit with this page. This only confirms that it is the correct unit. Also have the fault memory read out beforehand, because only this result shows whether the control unit itself is defective or whether a connector 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 D09J-57K30A work?

First, have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit. Next, create a repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, replaces defective components, deletes stored crash data and runs a function test. Your own unit is then returned to you.

Processing at Airbag24 usually takes 3–4 working days. This time refers only to checking, repairing and testing there.

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 D09J-57K30A get to Airbag24?

You send the control unit D09J-57K30A as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

Place the printed repair order in the parcel and pack the unit shock-resistant.