Airbag control unit with part number AM5T14B321AG

What is the function of the Airbag Control Unit AM5T14B321AG?

The Airbag Control Unit AM5T14B321AG is the central control unit (SRS module) for the occupant protection system in the Ford Grand C-Max II (2010–2019). It continuously monitors the vehicle’s sensors to ensure precise, split-second deployment of airbags and seatbelt pretensioners in the event of a crash. A malfunction disables the entire system.

As the “brain” of passive safety, this module processes data from acceleration and yaw rate sensors. Based on this information, it determines whether and how extensively airbags should deploy to provide optimal protection for occupants.

Why does the AM5T14B321AG control unit fail?

The most common cause of failure is the storage of crash data after an accident, which can lock the control unit. Regardless of collisions, internal electronic faults in components can also lead to complete system failure. In both cases, these are hardware defects requiring repair.

After a crash, the module permanently stores collision data and self‑locks for safety reasons. This condition cannot be resolved simply by clearing the fault memory; instead, a professional reset of the internal memory chips to factory settings is required.

Electronic faults may also occur without external impact, such as due to component aging or thermal stress. Therefore, diagnostics include checking for moisture damage or previous improper repair attempts. Similar Ford modules like 3M5T-14B056-BG or devices from Siemens/Bosch (e.g., 0 285 xxx) are frequently affected by such defects and are repairable.

How do you recognize a defect in the AM5T14B321AG?

A clear indication is the airbag warning light (SRS lamp) that remains steadily illuminated or flashes in the instrument cluster. Often, communication with the control unit via diagnostic equipment becomes impossible. Additional symptoms include a non‑functioning clock or complete module failure when exposed to heat.

The most obvious symptom is the airbag indicator light, which fails to turn off after starting the vehicle and stays on for about 30 seconds or continuously. This signals that the safety system is not operational and will not deploy airbags in an emergency.

Another serious sign is when the workshop can no longer access the control unit using diagnostic tools. The fault memory typically displays “No communication with airbag control unit,” making targeted troubleshooting impossible.

In some cases, the defect also manifests through unusual accompanying issues, such as a malfunctioning clock or total system failure once the device reaches a certain operating temperature.

In which vehicles is the AM5T14B321AG installed?

The control unit with part number AM5T14B321AG is specifically designed for the second-generation Ford Grand C‑Max. It is used in both the original model and the facelifted version. Airbag24 offers professional repair services exclusively for these models.

At Airbag24, we repair part number AM5T14B321AG for the following Ford models:

Ford Grand C‑Max II (model years 2010–2015)

Ford Grand C‑Max II Facelift (model years 2015–2019)

Is repairing the AM5T14B321AG worthwhile?

Yes, repair is the most cost-effective solution. Compared to a new unit, which can cost up to €750, repairs save between 50% and 90% of the expense. The repaired control unit is fully functional, and no re‑coding of the vehicle is required.

The significant cost savings represent the primary advantage. Instead of investing heavily in a new part, the existing hardware is expertly refurbished, conserving both budget and resources.

Since the original vehicle control unit is repaired, all vehicle‑specific data and coding remain intact. After repair, the module can be easily reinstalled (“plug-and-play”) and immediately operates without time‑consuming programming at a specialized workshop.

Each repair also comes with a 12‑month warranty, providing added peace of mind.

How is the AM5T14B321AG control unit professionally repaired?

At Airbag24, repairs follow a standardized process: After removal and shipment, the control unit undergoes thorough fault analysis. Next, crash data is cleared, defective components are replaced, and all functions are tested on a test bench before being returned with a 12‑month warranty.

The process begins with the proper removal of the control unit, usually located in the driver’s area beneath the dashboard. The securely packaged unit is then sent to Airbag24.

Our technicians perform a systematic diagnosis to identify the exact cause of the fault. The repair process includes erasing crash data, repairing or replacing defective electronic components, and restoring the module to its factory settings. A final functional test ensures that the module is operating perfectly again.

What shipping options does Airbag24 offer?

Airbag24 provides flexible and secure shipping solutions. For sending your unit to us, you can either ship it yourself or arrange a convenient UPS pickup. For returning the repaired unit, we offer free standard UPS shipping as well as faster UPS Express shipping—both available with cash-on-delivery options.

You have two ways to send us your defective control unit: you can pack it yourself and mail it to us, or use our paid UPS pickup service from your preferred location. Of course, you’re also welcome to drop off the unit in person.

Once the repair is successfully completed, we’ll ship the unit back to you according to your preference. You can choose between free standard UPS shipping (1–3 business days) and faster UPS Express shipping (1–2 business days). Both options are also available with cash-on-delivery, and self-pickup is an additional option.