Airbag control unit with part number TK48-57K30A

What does the airbag control unit TK48-57K30A do?

The airbag control unit TK48-57K30A is the central control unit of the SRS restraint system for Mazda. It evaluates the crash sensors and determines which airbags and seatbelt pretensioners are triggered.

Within milliseconds it makes this decision and monitors the entire system continuously. It reports faults via the airbag warning light so that the driver can see it.

After an accident it stores crash data and locks itself. The crash sensors provide the basis for this, and the control unit processes their data into a decision for the restraint system.

Why does the control unit TK48-57K30A fail?

For TK48-57K30A the most common cause lies in crash data stored after an accident, even if no airbag has deployed. This data cannot be removed with a normal diagnostic tool. Further causes are aged electronics, cold solder joints, moisture and corrosion at plug connections, as well as voltage spikes.

Moisture and corrosion attack the contacts, which can lead to poor connections. Which cause applies only becomes clear during the check.

Voltage spikes, for example from a weak battery or jump-starting, can additionally stress the unit. This belongs to the causes that are clarified during the check.

How can you tell that the TK48-57K30A is defective?

The airbag warning light on the TK48-57K30A signals a fault when it lights up permanently or intermittently. In addition, a fault message appears in the instrument cluster.

If the diagnostic tool cannot establish a connection to the control unit, or the fault memory cannot be cleared, that indicates a defect. Both are signs you should take seriously.

In an emergency, airbags and seatbelt pretensioners may then not trigger. A prompt clarification is therefore important.

Which vehicles is the TK48-57K30A fitted in?

The following vehicles are fitted with the TK48-57K30A: Mazda CX-9 TC (2016-2020) and TC Facelift (2020-2023).

The list shows the models that Airbag24 has on record for this part number.

• Mazda CX-9 TC (2016-2020)
• Mazda CX-9 TC Facelift (2020-2023)

Whether the part number on the label of the removed unit matches this page only tells you whether you have the correct control unit. Having the fault memory read out brings clarity as to whether the unit itself is the cause or whether a plug or cable is.

For the same vehicles, we also repair control units with the part numbers TD1157K30, TD1157K30C, TD1157K30D, TE6957K30A, TK48-57-K30B, TK4857K30C.

How does the repair of the TK48-57K30A work?

First have the fault memory read out and enclose the log. Then disconnect the battery, remove the control unit TK48-57K30A, and create a repair order online. Then send the unit in, well packed.

Airbag24 checks the unit on the test bench, replaces defective components, deletes the crash data and runs a function test. Processing usually takes 3–4 working days before the unit goes back.

The order of steps is binding for safety reasons. 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 TK48-57K30A get to Airbag24?

You send the TK48-57K30A as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends it back by UPS.

Enclose the printed repair order. Choose packaging that absorbs shocks for the unit.