Airbag control unit with part number BC3Z-14B321-M

What does the airbag control unit BC3Z-14B321-M do?

The airbag control unit BC3Z-14B321-M is the central control unit of the restraint system (SRS) for Ford. It processes the measurements from the crash sensors, selects the appropriate airbags and seatbelt pretensioners in an accident, and monitors the entire system. After an accident it stores crash data and locks itself.

If the unit detects a fault, it creates an entry in the fault memory. The message appears via the airbag warning light in the instrument cluster.

The control unit works constantly in the background. It checks the power supply, the wiring to the sensors and the activation of the firing units.

Why does the control unit BC3Z-14B321-M fail?

Stored crash data is the most common cause after an accident, even if no airbag has deployed. In addition come ageing electronics, cold solder joints, moisture and corrosion on plug connectors, and voltage spikes, for example from a weak battery or jump starting.

Crash data cannot be erased with an ordinary diagnostic tool. That is exactly why the fault remains, even if the other checks show nothing unusual.

The other causes develop gradually. Electronic components age, solder joints can come loose, and moisture promotes corrosion on plug connectors. Voltage spikes occur, for example, with a weak battery or an incorrectly performed jump start.

How can you tell that the BC3Z-14B321-M is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently. In addition, an error message appears in the instrument cluster, the diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared.

In an emergency, airbags and seatbelt pretensioners may not deploy because of such a fault. That is why you should not treat the fault lightly, but have the system checked promptly.

The warning light is the direct indication of the defect. The cause is only established by the test.

Which vehicles is the BC3Z-14B321-M fitted in?

The airbag control unit BC3Z-14B321-M is fitted in these vehicles: Ford F-Series Super Duty 3 P473 (2011-2016).

The overview of the models with this control unit follows here.

• Ford F-Series Super Duty 3 P473 (2011-2016)

First check whether the part number on the label of the removed unit matches this page. This only shows that it is the correct unit. Have the fault memory read out beforehand. 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 DC3T-14B321-BA, DC3T-14B321-BB, DC3T-14B321-DC, DC3Z-14B321-D.

How does the repair of the BC3Z-14B321-M work?

First have the fault memory read out and enclose the log. Then disconnect the battery, and only then remove the control unit. Create a repair order online, pack the unit well and send it in. Processing at Airbag24 usually takes 3–4 working days.

The sequence serves your safety. At Airbag24 the unit is inspected on the test bench, defective components are replaced, the stored crash data is erased, and a function test completes the work. The unit then returns to you.

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 BC3Z-14B321-M get to Airbag24?

You send the unit to Airbag24 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back to you by UPS.

Include the printed repair order in the parcel. Pack the control unit shock-resistant before you hand it over.