Airbag control unit with part number KB3T-14B321-BD

What does the airbag control unit KB3T-14B321-BD do?

The airbag control unit KB3T-14B321-BD is the central control unit of the restraint system (SRS) at Ford. It evaluates the signals from the crash sensors and, in a crash, determines within milliseconds which airbags and seatbelt pretensioners are triggered. It also monitors the entire system without pause.

Detected faults are shown via the airbag warning light. After a crash, it stores crash data and locks itself.

Without this control unit, the restraint system lacks the point that decides on triggering.

Why does the control unit KB3T-14B321-BD fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered; a normal diagnostic tool does not erase it. Other causes are ageing electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes.

Stored crash data remains in the control unit until it is removed during the repair. The fact that no airbag was triggered does not change this.

The other causes concern the electronics themselves and their connections. Ageing components can fail, cold solder joints lose contact, and moisture combined with corrosion attacks the plug connections.

Voltage spikes arise, for example, from a weak battery or when starting with jump leads, and additionally stress the electronics.

How can you tell that the KB3T-14B321-BD is defective?

Typical is an airbag warning light in the instrument cluster that stays on permanently or at times. Added to this are a fault message in the instrument cluster, a diagnostic tool without a connection to the control unit, and a fault memory that cannot be cleared.

These warning signs indicate that the restraint system is not working reliably. In an emergency, the airbags and seatbelt pretensioners may then fail to trigger.

So take such signs seriously and have the fault memory read out.

Which vehicles is the KB3T-14B321-BD fitted in?

The information applies to this part number. The airbag control unit KB3T-14B321-BD is fitted in these vehicles: Ford Ranger 3 2nd Facelift (2019-2023).

Here are the vehicles for which this part number is recorded:

• Ford Ranger 3 2nd Facelift (2019-2023)

Compare the part number on the label of the removed unit with this page. That only tells you whether it is the correct unit. Which cause lies behind the failure, whether the control unit is defective or a plug or cable, becomes clear only from the fault memory that has been read out.

For the same vehicles, we also repair control units with the part numbers AB3914B321CF, BL5Z-14B321-A, ML3Z-14B321-Z, XL5A14B321AD.

How does the repair of the KB3T-14B321-BD work?

First have the fault memory read out and keep the log ready, then disconnect the battery and remove the control unit. Only then create a repair order online and send the well-packed unit. Checking, repairing and testing at Airbag24 usually take 3–4 working days.

Airbag24 checks the unit on the test bench, replaces defective components, erases the stored crash data and carries out a function test. Afterwards, your own unit goes back 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 KB3T-14B321-BD get to Airbag24?

Either you pack the unit yourself as a parcel, or you book a UPS collection for an extra charge. After the repair, UPS returns the unit to you. The printed repair order goes into the parcel, and the unit needs shockproof packaging.

Shockproof packaging protects the control unit along the entire transport route.