Airbag control unit with part number HC3T-14B321-BE

What does the airbag control unit HC3T-14B321-BE do?

The airbag control unit HC3T-14B321-BE is the central control unit of the restraint system (SRS) of Ford. It evaluates the signals from the crash sensors and, in the event of an accident, decides within milliseconds which airbags and seatbelt pretensioners are triggered.

The unit also monitors the system continuously. It indicates faults via the airbag warning light.

After an accident, the control unit stores crash data and locks itself.

Why does the control unit HC3T-14B321-BE fail?

The most common cause: crash data stored after an accident, even if no airbag has deployed. Other causes are ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data remain in memory even if the vehicle was able to keep driving after the accident. A standard diagnostic tool cannot reach this entry.

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

Which of these causes applies only becomes clear during the test on the test bench.

How can you tell that the HC3T-14B321-BE is defective?

A defect shows up as the airbag warning light in the instrument cluster lighting up permanently or intermittently, as an error message in the instrument cluster, as a lack of connection to the diagnostic tool, and as a fault memory that cannot be cleared.

In detail, these signs stand out:

• airbag warning light on permanently or intermittently
• error message in the instrument cluster
• the diagnostic tool gets no connection to the control unit
• the fault memory cannot be cleared

In an emergency, the airbags and seatbelt pretensioners may then not trigger as intended. For that reason, such a warning should be checked promptly.

Which vehicles is the HC3T-14B321-BE fitted in?

The control unit HC3T-14B321-BE is fitted in these vehicles: Ford F-Series Super Duty 4 P558 (2017-2022).

The assignment is based on the details for this part number. The vehicles from it are listed here:

• Ford F-Series Super Duty 4 P558 (2017-2022)

First compare the part number on the label of the removed unit with this page. This only confirms that it is the right unit. Also have the fault memory read out beforehand, because only the log shows whether the control unit is defective or whether a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers HC3Z-14B321-B, LC3Z-14B321-B, PC3T-14B321-YC.

How does the repair of the HC3T-14B321-BE work?

First read out the fault memory and enclose the log, then disconnect the battery and remove the control unit. Next, create a repair order online and pack the unit well for posting. Airbag24 checks it, replaces defective components, erases the crash data and carries out a function test.

The sequence is fixed for safety reasons. The control unit is only removed after the battery has been disconnected.

At Airbag24, the unit is examined on the test bench. Checking, repairing and testing usually takes Airbag24 3–4 working days. After that, your own unit is returned 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 HC3T-14B321-BE get to Airbag24?

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

Put the printed repair order into the parcel and pack the control unit shockproof.