Airbag control unit with part number TD84-57K30

What does the airbag control unit TD84-57K30 do?

The airbag control unit TD84-57K30 takes over the central control of the restraint system (SRS) in the Mazda. It reads the crash sensors, decides in an emergency on the triggering of airbags and seatbelt pretensioners, and monitors the system continuously. After an accident it stores crash data and locks itself.

Triggering takes place in fractions of a second. The unit detects faults itself and shows them via the airbag warning light.

Why does the control unit TD84-57K30 fail?

Stored crash data is the most common cause with the TD84-57K30, even if no airbag has been triggered, and a normal diagnostic tool cannot erase it. Other causes are ageing electronic components, cold solder joints, moisture and corrosion on the plug connections, and voltage spikes, for example from a weak battery or a jump start.

The crash data are stored inside the control unit itself. For that reason, emptying the fault memory is not enough, because the data remain in the unit.

The other causes concern components and connections. Ageing makes the electronics more susceptible, moisture and corrosion attack the plug contacts, and voltage spikes load the circuitry.

How can you tell that the TD84-57K30 is defective?

On the TD84-57K30, you recognise a defect by the airbag warning light in the instrument cluster, which stays on constantly or intermittently. In addition, a fault message appears, the diagnostic tool cannot reach the control unit, and the fault memory cannot be cleared.

As long as these signs persist, airbags and seatbelt pretensioners may fail to trigger in an emergency. The restraint system as a whole is affected, even if only a single indicator lights up.

Which vehicles is the TD84-57K30 fitted in?

The airbag control unit TD84-57K30 is fitted in these vehicles: Mazda Mazda5 CW (2010-2013) and CW Facelift (2013-2018).

The vehicles in detail:

• Mazda Mazda5 CW (2010-2013)
• Mazda Mazda5 CW Facelift (2013-2018)

Compare the part number on the removed unit with this page, so that you know you have the correct control unit. Have the fault memory read out beforehand; only the log shows whether the control unit itself is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 285010636, 6300022037AA, C513-57-K30A.

How does the repair of the TD84-57K30 work?

You have the fault memory read out first and enclose the log. Then you disconnect the battery, remove the control unit and create a repair order online before sending it off well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 first examines the unit on the test bench, then replaces defective components. Stored crash data is erased, followed by the function test, and your own unit comes 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 TD84-57K30 get to Airbag24?

You send the control unit TD84-57K30 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

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