Airbag control unit with part number AB39-14B321-BH

What does the airbag control unit AB39-14B321-BH do?

The airbag control unit AB39-14B321-BH coordinates the restraint system (SRS) of Ford. Crash sensors supply it with measured values, from which it derives within milliseconds in an accident which airbags and seatbelt pretensioners are triggered.

During operation the control unit checks the entire installation without interruption. If it detects a fault, it switches on the airbag warning light in the instrument cluster.

After an accident the unit records crash data and locks itself.

Why does the control unit AB39-14B321-BH fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. Added to this are aged electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes.

Crash data cannot be erased with an ordinary diagnostic tool. Airbag24 erases it during the repair.

Aged components, cold solder joints and moisture on plugs affect the electronics directly. Voltage spikes, for example from a weak battery or a jump start, put additional strain on them. Which of these causes applies in the individual case only becomes clear when the unit is examined.

How can you tell that the AB39-14B321-BH is defective?

The airbag warning light lights up permanently or intermittently, and a fault message appears in the instrument cluster. In addition, the diagnostic tool does not find the control unit, and the fault memory cannot be cleared.

Typical signs are:

• Airbag warning light permanently on
• Airbag warning light on intermittently
• Fault message in the instrument cluster
• No connection to the control unit via the diagnostic tool
• Fault memory cannot be cleared

With these signs, airbags and seatbelt pretensioners may not trigger in an emergency. Instead of waiting, it is advisable to have the fault memory read out.

Which vehicles is the AB39-14B321-BH fitted in?

The control unit AB39-14B321-BH is fitted in these vehicles: Ford Ranger 3 (2011-2015), 3 1st Facelift (2016-2019) and 3 2nd Facelift (2019-2023).

Here is the overview of the stored models:

• Ford Ranger 3 (2011-2015)
• Ford Ranger 3 1st Facelift (2016-2019)
• Ford Ranger 3 2nd Facelift (2019-2023)

Before sending in the unit, check the following points. Comparing the part number on the label of the removed unit with this page only confirms that it is the correct unit. Evaluating the fault memory, on the other hand, clarifies 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 AB3914B321CF, KB3T-14B321-BD.

How does the repair of the AB39-14B321-BH work?

First you have the fault memory read out and attach the log. Then you disconnect the battery and remove the control unit. After that you create a repair order online and send in the well-packed unit.

Airbag24 checks the unit on the test bench and replaces defective components. Stored crash data is deleted by Airbag24 before a function test follows.

For checking, repairing and testing, Airbag24 usually needs 3–4 working days. 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 AB39-14B321-BH get to Airbag24?

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

Enclose the printed repair order and pack the unit shock-proof.