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

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

The AB39-14B321-DG controls the restraint system (SRS) for Ford. From the signals of the crash sensors, it calculates within milliseconds which airbags and seatbelt pretensioners are triggered in an accident, and it shows faults via the airbag warning light. After an accident, the unit stores crash data and locks itself.

Monitoring continues in the background even when the vehicle drives normally. Every sensor, every wire and every output stage is checked for plausibility, and deviations are recorded in the memory.

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

On the AB39-14B321-DG, the most common cause is stored crash data from an accident, even when no airbag has deployed. A normal diagnostic tool cannot erase this data; aged components, cold solder joints, moisture and voltage spikes are also possible causes.

How strongly each of these causes contributes cannot be determined without reading out the fault memory. The list summarises the other causes:

• aged electronic components
• solder joints that have gone cold
• moisture and corrosion on the connectors
• voltage spikes, for example from a weak battery or jump-starting

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

The airbag warning light in the instrument cluster lights up permanently or intermittently on the AB39-14B321-DG, and a fault message appears in the instrument cluster. In addition, the diagnostic tool has no connection to the control unit, and the fault memory cannot be cleared.

As long as the fault persists, airbags and seatbelt pretensioners may not deploy in an emergency. The warning light is therefore a signal that must be taken seriously, even if the car otherwise runs without any problems.

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

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

The vehicles in which this unit is fitted are listed here:

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

Compare the part number on the label of the removed unit with this page. This only confirms that you have the correct unit in front of you. Be sure to have the fault memory read out beforehand, because only the result shows whether the control unit is defective or whether a connector 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-DG work?

First have the fault memory read out, then disconnect the battery and remove the AB39-14B321-DG; afterwards create a repair order online. Processing at Airbag24 usually takes 3–4 working days.

Attach the fault memory log to the unit, then pack it well and send it in.

Airbag24 then checks the unit on the test bench, repairs damaged components and deletes stored crash data. Only after that does the team carry out a function test, and 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 AB39-14B321-DG get to Airbag24?

You send the AB39-14B321-DG in as a parcel or book a UPS collection for an extra charge. Airbag24 sends your own unit back to you by UPS after the repair.

Put the printed repair order in the parcel. Pack the unit shockproof so that it arrives undamaged.