Airbag control unit with part number AM5T-14B321-AG

What is the function of the Airbag Control Unit AM5T-14B321-AG?

The airbag control unit with part number AM5T-14B321-AG is the central control module for the Supplemental Restraint System (SRS) in the second-generation Ford C-Max (2010–2019). It continuously processes data from collision and seatbelt pretensioner sensors to precisely and promptly deploy airbags and seatbelt pretensioners in the event of a crash.

As a core component of passive vehicle safety, this module interprets signals from various crash sensors throughout the vehicle. Based on this data, it determines within milliseconds whether a collision has occurred that necessitates activation of the restraint systems.

In addition to deploying airbags, it also controls seatbelt pretensioners and maintains constant communication with the vehicle’s onboard electrical system. A properly functioning control unit is therefore essential for occupant protection and compliance with safety standards.

Why does the Airbag Control Unit AM5T-14B321-AG fail?

The most common causes of failure for the AM5T-14B321-AG control unit are stored crash data following an accident—even without airbag deployment—as well as internal hardware defects. These can arise from moisture, overvoltage, or vibrations, leading to malfunctions in circuit board components or communication interruptions.

A very frequent reason for repair is the storage of crash data in the unit’s internal memory. Even in minor collisions where only the seatbelt pretensioners activated—or no visible deployment occurred—the control unit locks up and reports a persistent fault.

Electronic faults are another primary cause. Issues such as moisture ingress can lead to corrosion on the circuit board, while voltage surges in the vehicle’s electrical system may damage sensitive components like capacitors. Broken solder joints caused by continuous vibration within the vehicle are also a typical source of failure.

Specifically for Ford vehicles, a fault related to the front crash sensor (error code B0094:93AF) may also occur. Often, the root cause lies not in the sensor itself but in an internal malfunction within the AM5T-14B321-AG control unit that disrupts signal processing.

How do you recognize a defect in the AM5T-14B321-AG?

A defect in the AM5T-14B321-AG control unit primarily manifests as a permanently illuminated airbag warning light on the instrument cluster. Additional symptoms include loss of communication with diagnostic equipment (error code B1000) or specific entries in the fault memory such as “internal error” (e.g., 65535).

The clearest indication is the persistently lit red airbag warning light. It fails to extinguish after starting the vehicle, signaling a critical, stored fault in the SRS system and resulting in a significant deficiency during the main inspection (TÜV).

In many cases, the control unit becomes inaccessible via the OBD2 interface. Diagnostic tools cannot establish a connection, complicating troubleshooting and often pointing to a severe internal defect within the module.

When reading out error codes, entries such as B1000 (“control unit defective”), 65535 (“internal error”), or messages indicating insufficient supply voltage directly suggest a problem within the control unit itself. Even errors referencing faulty seatbelt pretensioners or sensors may stem from improper signal processing by the control unit.

In which models is the AM5T-14B321-AG control unit installed?

The airbag control unit with part number AM5T-14B321-AG is specifically designed for the Ford C‑Max. It is used in both the second vehicle generation and its facelift model. At Airbag24, we specialize in repairing this particular control unit.

At Airbag24, we repair the AM5T-14B321-AG control unit for the following Ford vehicle models:

Ford C‑Max II (model years 2010–2015)

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

How does repair work at Airbag24?

Repair of the AM5T-14B321-AG control unit at Airbag24 includes a detailed analysis of the circuit board, elimination of hardware defects, professional resetting of stored crash data, and a final functional test. We provide a 12-month warranty on every repair.

After sending the removed control unit to Airbag24, our technicians perform an initial inspection to verify the reported faults. It is recommended to read out the fault memory and attach a printout before removal to expedite diagnosis.

The actual repair takes place at the component level. Defective parts such as capacitors or other electronic modules are replaced, cold solder joints are re-soldered, and any moisture-related damage on the circuit board is addressed.

A key step is securely erasing the crash data from the internal memory. This unlocks the control unit again, restoring full functionality without the need for an expensive replacement.

Finally, the repaired module undergoes a comprehensive functional test. Since the vehicle’s original coding is preserved, re‑learning is usually not required after reinstallation.

What shipping options are available?

For repairing your control unit at Airbag24, you can either send it in yourself free of charge or arrange a convenient UPS pickup from your preferred location. For return shipping, we offer free standard UPS delivery as well as faster express options, both with cash-on-delivery available. Self‑pickup is also possible.

For sending your removed control unit to us, you have two choices: you can ship the package yourself or drop it off at our premises. Alternatively, you can use our portal to schedule a UPS pickup that collects the package directly from your home or workshop.

Once the repair is complete, we’ll return the unit to you as quickly as possible. Standard UPS shipping is free of charge.

If speed is of the essence, UPS Express shipping is available for an additional fee. Both standard and express shipping can be combined with cash-on-delivery upon request.

You also have the option to pick up your repaired control unit in person at our facility.