Airbag control unit with part number DM5T14B321EH

What is the function of the Airbag Control Unit DM5T14B321EH?

The airbag control unit with part number DM5T14B321EH is the central control module for the occupant safety system (SRS) in the Ford Grand C-Max II and C-Max II (model years 2010–2019). It processes data from the acceleration sensors and, in the event of a crash, determines whether to deploy airbags and seatbelt pretensioners.

As a core component of the passive safety system, this module—listed under Bosch reference 0285011578—is responsible for reliably detecting a collision and activating the appropriate restraint systems within milliseconds. It continuously monitors all connected sensors, airbag modules, and seatbelt pretensioners for proper functionality.

Why does the DM5T14B321EH control unit fail?

The most common cause of failure for the DM5T14B321EH is the storage of crash data after an accident, which locks the unit. Other reasons include internal electronic malfunctions or mechanical damage. This issue also affects identical control units with part numbers DM5T14B321RA, AM5T14B321AG, or F1CT14B321RC.

After a crash in which airbags or seatbelt pretensioners have deployed, the control unit irrevocably writes crash data into its internal memory. This is a manufacturer‑imposed safety measure that prevents reuse without inspection and reset, effectively locking the device.

In addition to crash‑induced lockouts, electrical disturbances in the vehicle’s wiring harness or age‑related wear of internal electronic components can also lead to malfunctions. Connector or wiring defects may further impair operation, often with the control unit itself being the root cause.

How do you recognize a fault in the DM5T14B321EH?

A typical defect of the DM5T14B321EH manifests as a permanently illuminated airbag warning light on the instrument cluster. Often, the control unit cannot be read by a diagnostic tool (no communication), or it reports an internal error that cannot be cleared.

The primary indicator is the red airbag warning light that fails to extinguish after starting the engine. This signals a critical fault in the safety system requiring immediate diagnosis.

Another clear symptom is when the workshop cannot access the SRS module—it does not respond to diagnostic requests, often pointing to an internal hardware failure or a blockage caused by crash data.

Unusual electrical phenomena may also occur, such as a faint glow in the speedometer illumination when locking the vehicle. Before proceeding with repairs, a qualified workshop should read out the fault memory to rule out external causes like defective sensors or seat occupancy mats.

In which vehicles is the DM5T14B321EH control unit installed?

The DM5T14B321EH airbag control unit is primarily used in models based on the Ford C‑Max platform. At Airbag24, we repair this control unit for the Ford Grand C‑Max II and the Ford C‑Max II from model years 2010 to 2019, including facelifted versions from 2015 onward.

Specifically, this module can be found in the following vehicle series:

Ford: Grand C‑Max II (DXA/CB7, DXA/CEU) from 2010 to 2019, and C‑Max II (DXA/CB7, DXA/CEU) from 2010 to 2019.

Depending on the vehicle configuration and production date, the control unit may also be installed in other models, such as the Fiat Linea. Verifying the correct part number is crucial in these cases.

How is the DM5T14B321EH repaired?

Repair at Airbag24 focuses on eliminating the electronic cause and erasing stored crash data. Upon receipt, technicians analyze the control unit, repair any defective components on the circuit board, and restore the device to factory condition. We provide a 12‑month warranty on every repair.

The process ideally begins with a diagnosis at your trusted workshop to rule out external sources of failure. Once it is confirmed that the control unit is defective, it is removed and sent to Airbag24 along with a detailed fault description.

Our technicians perform an initial inspection and proceed with professional repair. During this process, they not only erase crash data but also proactively address known electronic weaknesses. Final tests ensure the module is fully functional before it is returned to the vehicle.

What are the benefits of repairing the DM5T14B321EH?

Repairing the DM5T14B321EH is an economically and technically sensible alternative to costly replacement. Compared to a new unit, which often exceeds €1,000, you save significantly while preserving the original vehicle configuration, eliminating the need for time‑consuming reprogramming.

A key advantage is the substantial cost savings. While a new control unit can cost up to €1,080 according to the manufacturer, repair is significantly more affordable.

Since the original control unit—coded specifically for your vehicle—is repaired, you typically avoid the need for an expensive and time-consuming reprogramming at an authorized service center. The repaired unit can be easily reinstalled (plug-and-play).

In addition, you receive a 12-month warranty on the completed repair, providing you with added peace of mind.

What shipping options does Airbag24 offer?

For sending in your defective control unit, Airbag24 provides two convenient options: you can ship it yourself free of charge or arrange for UPS pickup at your preferred location. For return shipping, free and express options are available, including cash-on-delivery.

For outbound shipping, you can choose between free self‑shipping (e.g., via mail or a courier of your choice) or the convenient UPS pickup service. You can also drop off the package directly at our premises.

For return shipping, you have your choice: standard UPS shipping is free. If you need the part back sooner, you can opt for UPS Express shipping. Both options can also be combined with cash-on-delivery. Alternatively, self‑pickup is also possible.