Airbag control unit with part number D3BT-14B321-AE

What does the airbag control unit D3BT-14B321-AE do?

The airbag control unit D3BT-14B321-AE controls the restraint system (SRS) for Ford. It evaluates the signals from the crash sensors and, in an emergency, decides within milliseconds which airbags and seatbelt pretensioners are triggered.

While driving, the unit monitors the entire system continuously. If it detects a fault, it shows this via the airbag warning light in the instrument cluster so that you can react in good time.

After an accident, the control unit stores crash data and locks itself. Only the repair lifts this lock.

Why does the control unit D3BT-14B321-AE fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed; a normal diagnostic tool cannot erase it. Other causes are ageing electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes, for example from a weak battery or a jump start.

Stored crash data burdens the control unit even when little can be seen on the vehicle from the outside. Airbag24 erases this data as part of the repair.

The other triggers develop gradually. A component ages, a contact oxidises, moisture gets into a plug. Without an inspection, this is hard to pin down from the outside.

How can you tell that the D3BT-14B321-AE is defective?

A defect shows up as the airbag warning light in the instrument cluster staying on permanently or intermittently. Added to this are a fault message in the instrument cluster, no connection between the diagnostic tool and the control unit, and a fault memory that cannot be cleared.

The warning light is the most important alert in this context. If it is lit, have the system checked promptly, even if the vehicle is driving normally.

In an emergency, airbags and seatbelt pretensioners may fail to deploy. For this reason, every warning of this kind should be taken seriously before you continue driving.

Which vehicles is the D3BT-14B321-AE fitted in?

The D3BT-14B321-AE is fitted in these vehicles: Ford Fiesta 7 ’09 (2008-2017).

The list below shows the vehicles assigned to this part number:

• Ford Fiesta 7 ’09 (2008-2017)

Two steps will help you proceed safely. First, compare the part number on the label of the removed unit with this page; this only confirms that you have the correct unit. Also have the fault memory read out in advance, because only this result shows whether the control unit itself is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers C1BT-14B321-CF, H1BT-14B321-AH, H1BT-14B321-AJ.

How does the repair of the D3BT-14B321-AE work?

First have the fault memory read out and enclose the log. Then disconnect the battery, remove the control unit and create a repair order online. Testing, repair and the function test at Airbag24 usually take 3–4 working days.

Airbag24 checks the unit on the test bench and replaces defective components. Stored crash data is then erased and a function test is carried out before your own unit is sent back to you.

The sequence is fixed for safety reasons: the control unit may only be removed once the battery has been disconnected. You create the repair order online before sending the unit in.

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 D3BT-14B321-AE get to Airbag24?

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

Place the printed repair order in the parcel and pack the control unit shock-resistant so that it survives transport undamaged.