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

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

The airbag control unit AB39-14B321-EH controls the restraint system (SRS) for Ford. It evaluates the crash sensors and, in a crash, decides within milliseconds which airbags and seatbelt pretensioners are triggered.

During operation it checks the system continuously and displays faults via the airbag warning light. The findings end up in the fault memory, where they can be read with a diagnostic tool.

After an accident the unit stores crash data and locks itself. This makes it a component that has to be handled with particular care during every repair.

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

Crash data stored after an accident is the most common cause with the AB39-14B321-EH, even if no airbag has triggered. The other causes are listed below.

A normal diagnostic tool cannot erase this crash data.

The remaining causes in detail:

• electronic components that age over time
• cold solder joints
• moisture or corrosion on plug connectors
• voltage spikes, for example from jump-starting

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

The airbag warning light in the instrument cluster lights up permanently or intermittently when the AB39-14B321-EH is defective. In addition there may be error messages in the instrument cluster, no contact between the diagnostic tool and the control unit, and a fault memory that cannot be erased.

Such signs show the condition directly. In an emergency, airbags and seatbelt pretensioners may not trigger, and that calls for a check.

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

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

The list below shows the vehicles in detail.

• 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 of the removed unit with this page confirms that the unit is the right one. What matters is the fault memory: it shows whether the control unit itself is defective or whether a plug or cable is the cause. Have it read out in advance.

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-EH work?

Start the process by having the fault memory of the AB39-14B321-EH read out and enclose the log with the unit. Next, disconnect the battery, and only then remove the unit. Finally, create a repair order online and send the unit in.

This sequence is fixed for safety reasons.

At Airbag24 the unit is checked on the test bench, defective components are replaced, stored crash data is erased and a function test is carried out. Afterwards your own unit is returned to you. Checking, repairing and testing usually take 3–4 working days.

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-EH get to Airbag24?

You send the AB39-14B321-EH in as a parcel, or you book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

Shipping requires shock-proof packaging and the printed repair order.