Airbag control unit with part number HB5T-14B321-AA

What does the airbag control unit HB5T-14B321-AA do?

The airbag control unit HB5T-14B321-AA is the link between the crash sensors and the deployment units of the restraint system (SRS) of Ford. It evaluates the sensor signals, decides in the event of a crash within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the system at all times. It shows faults via the airbag warning light.

In normal operation you notice nothing of this. Unit and vehicle work unobtrusively until a fault occurs or an accident happens.

After an accident the control unit stores crash data and locks itself. That is one of the things you should know about this unit.

Why does the control unit HB5T-14B321-AA fail?

The most common cause is crash data that remains in memory after an accident, even when no airbag has been triggered. The other causes are aged electronics, cold solder joints, moisture at the plugs, corrosion and voltage spikes.

Standard diagnostic tools cannot change this data. Airbag24 carries out the erasure itself.

Voltage spikes that occur when starting or with a weak battery also stress the unit. Over the years, solder connections and contacts wear out when moisture is added.

How can you tell that the HB5T-14B321-AA is defective?

The airbag warning light in the instrument cluster comes on permanently or intermittently, an error message appears, the diagnostic tool finds no connection to the control unit, and the fault memory persists. In a crash, the airbags and seatbelt pretensioners may then fail to deploy.

This light is a warning you should take seriously. A check will lead you to the cause, which you can then address specifically.

Which vehicles is the HB5T-14B321-AA fitted in?

In these vehicles the unit HB5T-14B321-AA is installed: Ford Explorer 5 (2011-2019).

For reference, here is the list of models.

• Ford Explorer 5 (2011-2019)

Comparing the label with this page only shows that the unit matches the part number, nothing more. So have the fault memory read out before removal. Only this result shows whether the control unit itself is affected or whether a plug or cable is involved.

For the same vehicles, we also repair control units with the part numbers BB5T-14B321-AH, DB5T-14B321-AE, DB5T-14B321-AF, DB5T-14B321-AG, EB5T-14B321-AA, GB5T-14B321-AC.

How does the repair of the HB5T-14B321-AA work?

You start by reading out the fault memory and enclosing the log. Then disconnect the battery, remove the control unit, create a repair order online and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days, during which the unit is checked, repaired and tested.

On the test bench it becomes clear which components are affected. Replacing them, deleting the crash data and a function test follow as the next steps.

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 HB5T-14B321-AA get to Airbag24?

You can send the unit as a parcel or have UPS collect it for an extra charge. The return journey to you also runs via UPS.

Do not forget to enclose the printed repair order, and pack the control unit shock-proof.