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

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

The airbag control unit AB39-14B321-GB is the evaluation unit of the restraint system (SRS) in Ford. It processes the messages from the crash sensors, decides in an accident in fractions of a second on triggering, and monitors the entire system continuously. It reports faults found via the airbag warning light.

If the vehicle is involved in an accident, the unit then stores crash data and locks itself. This gives the control unit a special role, which must be taken into account in every repair.

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

With the AB39-14B321-GB, the most common cause is stored crash data. It remains in memory even when no airbag has deployed, and a normal diagnostic tool cannot erase it. Ageing, connection problems and voltage fluctuations also play a role.

At Airbag24, stored crash data is erased in the course of every repair on this unit. The other causes concern the hardware and the power supply of the control unit:

• ageing electronic components
• cold solder joints
• moisture and corrosion at plug connections
• voltage spikes, for example from a weak battery or a jump start

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

A defect on the AB39-14B321-GB can be recognised by several signs, which can also occur together. The airbag warning light in the instrument cluster is the most important signal.

Typical signs at a glance:

• The airbag warning light lights up permanently or intermittently.
• A fault message appears in the instrument cluster.
• The diagnostic tool has no connection to the control unit.
• The fault memory cannot be cleared.

In this case, airbags and seatbelt pretensioners may not deploy in an emergency. So have the condition checked promptly.

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

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

Our assignment lists the following models for this part number:

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

Comparing the part number on the label with this page only shows that you have the right unit in front of you. Whether the control unit is defective, or a connector or cable is the cause, is shown only by the fault memory read out beforehand.

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-GB work?

First have the fault memory read out and the log enclosed, then disconnect the battery and only then remove the AB39-14B321-GB. Next, create a repair order online and send the unit off well packed. Airbag24 checks it on the test bench, repairs defective components, erases the crash data and carries out a function test before the unit goes back.

This order is for your safety, because removal starts only once the battery is disconnected. At Airbag24, processing usually takes 3–4 working days and covers only checking, repairing and testing.

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-GB get to Airbag24?

Send the control unit AB39-14B321-GB as a parcel, or book a UPS collection for an extra charge. Airbag24 sends the unit back to you by UPS after the repair.

Put the printed repair order into the parcel, and pad the unit so it is shockproof.