Airbag control unit with part number 4S7T-14B056-AC

What does the airbag control unit 4S7T-14B056-AC do?

The airbag control unit 4S7T-14B056-AC controls the restraint system (SRS) of Ford. It evaluates the signals from the crash sensors and determines in an accident, within milliseconds, which airbags and seatbelt pretensioners are triggered. It shows faults via the airbag warning light.

The system is checked continuously during operation. Faults found are stored in the fault memory, which a diagnostic tool can query.

After an accident the control unit stores crash data and locks itself.

Why does the control unit 4S7T-14B056-AC fail?

Stored crash data is the most common cause, even if no airbag was triggered. Ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes are also considered.

Crash data remains in the unit after an accident. A standard diagnostic tool cannot remove it, and Airbag24 deletes it during the repair.

The other causes mainly concern the electronics and their contacts. Solder joints can go cold, moisture and corrosion damage plug connections, and voltage spikes stress the components.

How can you tell that the 4S7T-14B056-AC is defective?

The airbag warning light lights up permanently or intermittently, and a fault message appears in the instrument cluster. The diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared. Airbags and seatbelt pretensioners may then fail to deploy in an emergency.

The warning light is a direct indication from the system of a fault. It shows the defect and should therefore be taken seriously.

Only the read-out fault memory reveals whether the control unit itself is defective. A plug or a cable can trigger similar messages.

Which vehicles is the 4S7T-14B056-AC fitted in?

Check your vehicle against this list. The airbag control unit 4S7T-14B056-AC is fitted in these vehicles: Ford Mondeo 3 ’01 Facelift (2003-2007).

The matching vehicles for this part number are compiled here:

• Ford Mondeo 3 ’01 Facelift (2003-2007)

Compare the part number on the label of the removed unit with this page. That only ensures that it is the correct unit. Have the fault memory read out in addition beforehand, because only the log shows whether the control unit is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 1S7T-14B056-BG, 3S7T-14B056-AB, 4S7T-14B056-AB, AM2T-14B321-AC.

How does the repair of the 4S7T-14B056-AC work?

For the control unit 4S7T-14B056-AC, create a repair order online after reading out the fault memory. Processing at Airbag24 usually takes 3–4 working days.

Beforehand, enclose the log, disconnect the battery and remove the control unit. Then send in the well-packed unit. Airbag24 checks it on the test bench, repairs defective components, deletes the crash data and carries out a function test. Your own unit is returned to you afterwards.

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 4S7T-14B056-AC get to Airbag24?

You send the unit in as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 returns the control unit 4S7T-14B056-AC to you by UPS.

Place the printed repair order in the parcel and pack the unit shock-proof.