Airbag control unit with part number NA1J-57K30A

What does the airbag control unit NA1J-57K30A do?

The airbag control unit NA1J-57K30A forms the central control of the restraint system (SRS) for Mazda. It evaluates the crash sensors, decides in an accident on the deployment of airbags and seatbelt pretensioners, and monitors the system continuously. After an accident it stores crash data and locks itself.

The evaluation takes place in fractions of a second as soon as an impact is measured. Faults are shown by the control unit via the airbag warning light in the instrument cluster.

Without a functioning control unit, the restraint systems cannot respond as intended in an emergency.

Why does the control unit NA1J-57K30A fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage peaks.

Crash data cannot be erased with a normal diagnostic tool. Once it has been stored, the fault message remains, even if the airbags are undamaged.

Aged electronics, cold solder joints and moisture impair the function inside the unit. Corrosion at the plugs increases the transition resistance, and voltage peaks, for example from a weak battery or a jump-start, can damage the electronics.

How can you tell that the NA1J-57K30A is defective?

A defect shows up at the airbag warning light, in error messages in the instrument cluster, in a missing connection to the diagnostic tool and in a fault memory that cannot be cleared. Airbags and seatbelt pretensioners may then fail to trigger in an emergency.

These signs indicate a defect:

• The airbag warning light stays on permanently.
• The warning light only comes on intermittently.
• An error message appears in the instrument cluster.
• A diagnostic tool does not find the control unit.
• The fault memory cannot be cleared.

The light indicates the fault as soon as it occurs, so an early look at the fault memory is worthwhile.

Which vehicles is the NA1J-57K30A fitted in?

The control unit NA1J-57K30A is fitted in these vehicles: Mazda MX-5 ND (from 2015).

The list for this part number:

• Mazda MX-5 ND (from 2015)

Comparing the part number on the label of the removed unit with this page only ensures that it is the right unit. Having the fault memory read out before the control unit is removed, on the other hand, shows whether the 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 0 285 014 161 Bosch, N243 57K K2 C, N243 57K30 A, N243 57K30 C, N243 57K30 D, N243-57-K30G.

How does the repair of the NA1J-57K30A work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit. Afterwards create a repair order online and send the unit in well packed. Airbag24 needs 3–4 working days as a rule for testing, repair and function test.

Airbag24 tests the unit on the test bench, replaces defective components, deletes stored crash data and carries out a function test. Afterwards your own unit is sent back 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 NA1J-57K30A get to Airbag24?

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

Put the printed repair order into the parcel and pack the unit shockproof.