Airbag control unit with part number MR3T-14B321-BA

What does the airbag control unit MR3T-14B321-BA do?

The airbag control unit MR3T-14B321-BA manages the restraint system (SRS) of Ford. It evaluates the crash sensors, decides in an accident within milliseconds on airbags and seatbelt pretensioners, and monitors the system continuously. After an accident it stores crash data and locks itself.

The unit receives the signals from the sensors and evaluates them. The decision on triggering is made in a fraction of a moment.

It reports faults via the airbag warning light in the instrument cluster. In addition, it records fault entries in the memory.

Why does the control unit MR3T-14B321-BA fail?

The most common cause with the MR3T-14B321-BA is crash data stored after an accident, even if no airbag has deployed. A standard diagnostic tool cannot erase it. Ageing electronics, cold solder joints, moisture and voltage spikes can also be causes.

Crash data remains in the unit until it is removed. At Airbag24 it is deleted as part of the repair.

A control unit can also fail without an accident, for example through ageing of the components or poor contacts at the plugs. Voltage spikes, for example from a weak battery or a jump start, put additional strain on the electronics.

How can you tell that the MR3T-14B321-BA is defective?

On the MR3T-14B321-BA, a defect shows up as an airbag warning light in the instrument cluster that stays on permanently or intermittently. Added to this are an error message, a diagnostic tool without connection and a fault memory that cannot be cleared.

The light is a clear signal that should not be ignored, even if the vehicle can still be driven normally.

If the connection to the control unit fails or the fault memory cannot be emptied, the system is faulty. In that case, airbags and seatbelt pretensioners may not deploy in an emergency.

Which vehicles is the MR3T-14B321-BA fitted in?

The MR3T-14B321-BA is fitted in these vehicles: Ford Mustang 6 S550 (2014-2023).

The following selection shows the vehicles with this control unit.

• Ford Mustang 6 S550 (2014-2023)

Before you remove the unit, compare the part number on the label with this information and have the fault memory read out. Only then can you be sure that the control unit is defective and not a plug or a cable.

For the same vehicles, we also repair control units with the part numbers 285010835, AM2T-14B321-AC, MR3T-14B321-EA.

How does the repair of the MR3T-14B321-BA work?

You read out the fault memory, enclose the log, disconnect the battery and remove the control unit. Then you create the repair order online and send the unit in well packed. At Airbag24, checking, repairing and testing take 3–4 working days as a rule.

On the Airbag24 test bench, defective components are replaced and the crash data is removed. A function test follows.

Your own unit is then returned 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 MR3T-14B321-BA get to Airbag24?

You send the control unit MR3T-14B321-BA as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS.

The printed repair order belongs in the parcel, and the unit should be packed shock-resistant.