Airbag control unit with part number RL3T-14B321-YB

What does the airbag control unit RL3T-14B321-YB do?

The control unit RL3T-14B321-YB is the control unit of the SRS restraint system in Ford vehicles. It evaluates the signals of the crash sensors, decides in a crash within milliseconds which airbags and seatbelt pretensioners are triggered, and checks the system constantly. If it detects a fault, it shows this via the airbag warning light.

Its tasks also include monitoring the sensors and the wiring that reaches the unit.

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

Why does the control unit RL3T-14B321-YB fail?

The cause is most often crash data stored after an accident, even if no airbag has deployed; a standard diagnostic tool does not make it disappear. Further causes are ageing electronics, cold solder joints, moisture and corrosion at plugs, and voltage spikes.

Crash data is stored in the memory during the accident and stays there. Airbag24 erases it during the repair of control unit RL3T-14B321-YB.

Components age even without an accident. Solder joints can go cold over time, and moisture and corrosion attack the contacts.

Voltage spikes, for example from a weak battery or a jump start, are a further reason for faults.

How can you tell that the RL3T-14B321-YB is defective?

A defect shows up on the airbag warning light in the instrument cluster, which lights up continuously or intermittently. Added to this are error messages in the instrument cluster, a disturbed connection to the diagnostic tool, and a fault memory that cannot be erased.

These signs occur:

• airbag warning light on continuously or intermittently
• error message in the instrument cluster
• diagnostic tool finds no control unit
• fault memory cannot be erased

In an emergency, airbags and seatbelt pretensioners may not trigger. The light should therefore be taken seriously.

Which vehicles is the RL3T-14B321-YB fitted in?

The control unit RL3T-14B321-YB from Ford is fitted in these vehicles: Ford F-150 14th generation (from 2020).

These vehicles are recorded for this part number:

• Ford F-150 14th generation (from 2020)

Comparing the part number on the label of the removed unit with this page tells you that you have the correct unit. Whether the control unit is defective or a plug or cable is the cause only becomes clear from the fault memory read out before removal.

For the same vehicles, we also repair control units with the part numbers HL3T-14B321-AC.

How does the repair of the RL3T-14B321-YB work?

Have the fault memory read out first; the log goes with the unit. Only then disconnect the battery and remove the control unit RL3T-14B321-YB. Finally, create the repair order online and pack the unit securely for dispatch.

Airbag24 then checks the unit on the test bench, repairs defective components, erases the stored crash data and carries out a function test. Afterwards your own unit goes back to you.

Processing usually takes 3–4 working days. This refers exclusively to the work at Airbag24.

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 RL3T-14B321-YB get to Airbag24?

You send the control unit RL3T-14B321-YB as a parcel to Airbag24 or book a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back to you by UPS.

Make sure the packaging is shock-proof and enclose the printed repair order.