Airbag control unit with part number BS7T-14B321-AC

What does the airbag control unit BS7T-14B321-AC do?

The BS7T-14B321-AC is the airbag control unit for the restraint system (SRS) of Ford. It evaluates the crash sensors and decides in an accident, within fractions of a second, which airbags and seatbelt pretensioners are triggered.

The system is monitored continuously by the control unit. It reports detected faults via the airbag warning light.

After an accident the unit stores crash data and locks itself. The next section covers the crash data in more detail.

Why does the control unit BS7T-14B321-AC fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. An ordinary diagnostic tool cannot clear it. Other causes are ageing electronics, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data remains in the unit after an accident, even if no airbag was triggered. An ordinary diagnostic scanner cannot remove it.

Electronics age, and solder joints can go cold. Moisture and corrosion at plugs disturb the connection.

Voltage spikes, for example from a weak battery or a jump-start, stress the electronics.

How can you tell that the BS7T-14B321-AC is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently, and an error message appears. In addition, the diagnostic tool cannot establish a connection to the control unit, and the fault memory cannot be cleared.

The warning light is the most important sign to watch. As long as it is lit or shows an error message, the airbags and seatbelt pretensioners may possibly not deploy in an emergency.

Have the system checked promptly, even if the vehicle otherwise drives normally.

Which vehicles is the BS7T-14B321-AC fitted in?

The BS7T-14B321-AC is fitted in these vehicles: Ford Mondeo 4 ’07 Facelift (2010-2014).

The list of related vehicles follows here.

• Ford Mondeo 4 ’07 Facelift (2010-2014)

Hold the part number on the label of the removed unit next to this page, and you will see whether you have the right unit in front of you. Whether the control unit itself is defective is shown only by the fault memory that you have read out beforehand.

For the same vehicles, we also repair control units with the part numbers 285010228, 670013905702, 7S7T-14B056-AC, 7S7T-14B056-AD.

How does the repair of the BS7T-14B321-AC work?

First have the fault memory read out and enclose the log, then disconnect the battery. Only then remove the control unit, create the repair order online and send in the well-packed unit. At Airbag24, testing, repairing and checking usually take 3–4 working days.

Airbag24 examines the unit on the test bench. If a component is defective, it is replaced where needed; the crash data is erased and a function test completes the work. Your own unit then goes 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 BS7T-14B321-AC get to Airbag24?

Send the unit to Airbag24 as a parcel or arrange a UPS collection for an extra charge. After the repair UPS brings the unit back to you. Include the printed repair order in the parcel and pack the control unit shock-resistant.

Make sure the unit sits firmly in the carton and nothing presses against the walls.