Airbag control unit with part number 4M5T-14B056-AB

What does the airbag control unit 4M5T-14B056-AB do?

The airbag control unit 4M5T-14B056-AB controls the restraint system (SRS) for Ford and coordinates its components. It evaluates the signals from the crash sensors and decides in a crash which airbags and seatbelt pretensioners are triggered.

The unit also monitors the wiring and the function of the connected components. If it detects a fault, it reports this via the airbag warning light in the instrument cluster.

After a crash, the unit stores crash data and locks itself.

Why does the control unit 4M5T-14B056-AB fail?

Stored crash data after a crash is the most common cause of a failure of the 4M5T-14B056-AB, even if no airbag has deployed. Further causes are components that age, cold solder joints, moisture and corrosion, and voltage spikes.

A normal diagnostic tool cannot remove this crash data. Airbag24 deletes it during the repair.

The further causes at a glance:

• aged electronic components
• cold solder joints
• moisture and corrosion on plug connections
• voltage spikes, for example from a weak battery or a jump start

An examination of the unit clarifies which of these causes is actually present.

How can you tell that the 4M5T-14B056-AB is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently and thus indicates a defect in the 4M5T-14B056-AB. In addition, there are an error message, a lack of connection for the diagnostic tool, and a fault memory that cannot be cleared.

If the finding persists, airbags and seatbelt pretensioners may not deploy in an emergency. This also applies when the vehicle otherwise runs without any abnormalities.

A prompt check of the fault memory clarifies whether the control unit itself is affected.

Which vehicles is the 4M5T-14B056-AB fitted in?

The assignment covers several models. The airbag control unit 4M5T-14B056-AB is fitted by Ford in these vehicles: Ford Focus 2 ’04 (2004-2007) and 2 ’04 Facelift (2004-2007); Ford C-Max 1 Facelift (2007-2010) and 1 (2003-2007).

The models in detail:

• Ford Focus 2 ’04 (2004-2007)
• Ford Focus 2 ’04 Facelift (2004-2007)
• Ford C-Max 1 Facelift (2007-2010)
• Ford C-Max 1 (2003-2007)

First compare the part number on the label of the removed unit with this page, so that you have the right unit in front of you. Secondly, have the fault memory read out before removal, because only this result shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 285001552, 2M5T-14B056-BD, 2M5T-14B056-DE, 3M5T-14B056-BG, 4M5T 14B056 AE, 4M5T-14B056-BJ.

How does the repair of the 4M5T-14B056-AB work?

First have the fault memory of the 4M5T-14B056-AB read out and attach the log. Then disconnect the battery; only afterwards remove the control unit. Then create a repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, repairs defective components, deletes stored crash data and carries out a function test.

Processing at Airbag24 usually takes 3–4 working days. You then receive your own unit back. 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 4M5T-14B056-AB get to Airbag24?

Send a parcel with the control unit 4M5T-14B056-AB to Airbag24, or book a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS.

Include the printed repair order in the parcel. Pack the unit shockproof before it goes off.