Airbag control unit with part number W2T80372

What does the airbag control unit W2T80372 do?

On the Mazda, the airbag control unit W2T80372 controls the restraint system (SRS). It receives the values from the crash sensors, works out within fractions of a second whether airbags and seatbelt pretensioners are to be triggered, and monitors the entire system.

A detected fault is reported by the device via the airbag warning light. After an accident it stores crash data and locks itself.

These processes run quietly in the background; the driver does not need to do anything for them.

Why does the control unit W2T80372 fail?

Crash data from an accident is the most common cause, even if no airbag has triggered; a normal diagnostic tool cannot be used to delete it, because the data cannot be removed with it. Other causes are ageing, cold solder joints, moisture and corrosion, and voltage spikes.

• Ageing of the electronics
• Cold solder joints
• Moisture and corrosion at plug connections
• Voltage spikes caused by a weak battery or a jump start

At Airbag24, crash data is deleted as part of the repair. Whether the causes listed above apply is established by the inspection.

How can you tell that the W2T80372 is defective?

A defect in the W2T80372 can be recognised by the airbag warning light, which lights up permanently or intermittently, by fault messages in the instrument cluster, by a diagnostic tool that cannot establish a connection, and by a fault memory that cannot be cleared.

The light is a direct indication from the vehicle that something is wrong in the restraint system. In this condition, airbags and seatbelt pretensioners may not trigger in an emergency.

A fault can also originate from a cable or connector, not from the control unit alone. That is exactly why only reading out the fault memory brings clarity.

Which vehicles is the W2T80372 fitted in?

The W2T80372 is fitted in these vehicles: Mazda MX-5 NC 1st Facelift (2008-2012), NC 2nd Facelift (2012-2015) and NC (2005–2008).

The following vehicles are stored for this part number:

• Mazda MX-5 NC 1st Facelift (2008-2012)
• Mazda MX-5 NC 2nd Facelift (2012-2015)
• Mazda MX-5 NC (2005–2008)

Comparing the part number on the label with this page ensures that it is the right device, but it says nothing about the cause. Having the fault memory read out, on the other hand, shows whether the control unit is defective or whether a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers NE51-57-K30C, NE51-57-K30D.

How does the repair of the W2T80372 work?

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

At Airbag24, the device first goes onto the test bench. Defective components are repaired, crash data is deleted and a function test is carried out. The device then returns to the sender.

Processing at Airbag24 usually takes 3–4 working days, and this time covers only the checking, repairing and testing.

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 W2T80372 get to Airbag24?

Shipping is either as a parcel that you send yourself, or with a UPS collection booked for an extra charge. Return after the repair is by UPS.

The printed repair order goes into the parcel. Pack the device shockproof.