Airbag control unit with part number TK3T-14B321-AC

What does the airbag control unit TK3T-14B321-AC do?

The airbag control unit TK3T-14B321-AC controls the restraint system (SRS) in vehicles from Ford. It processes the signals from the crash sensors and, in an accident, decides within milliseconds which airbags and seatbelt pretensioners deploy. After an accident, it stores crash data and locks itself.

Even during normal driving, the control unit constantly checks that all parts of the system are working correctly. If it finds a fault, it switches on the airbag warning light in the instrument cluster.

Why does the control unit TK3T-14B321-AC fail?

The most common cause is crash data that the unit stored after an accident, even if no airbag deployed. Other possible causes are aged electronic components, cold solder joints, moisture or corrosion on the plug connections, and voltage spikes. On the control unit TK3T-14B321-AC, deleting the crash data is often not possible; if you would like the crash data deleted, get in touch with Airbag24 briefly before sending the unit in, so that the part number can be checked.

Stored crash data remains in the memory of the unit; an ordinary diagnostic tool cannot delete it.

Electronic components age over the years, and cold solder joints lead to unreliable contacts. If moisture gets into the plug connections, corrosion forms and disrupts the signals. Voltage spikes, for example from a weak battery or after a jump start, put additional strain on the electronics.

How can you tell that the TK3T-14B321-AC is defective?

A fault on the TK3T-14B321-AC shows up in the airbag warning light in the instrument cluster, which stays on permanently or intermittently, and in a fault message. In addition, a diagnostic tool may be unable to connect to the control unit, or the fault memory cannot be cleared. In an emergency, the airbags and seatbelt pretensioners may then fail to deploy.

Look out for these signs:

• The airbag warning light stays on after the engine has started.
• The warning light comes on and goes off again while driving.
• The instrument cluster shows a fault message about the airbag system.
• The diagnostic tool cannot reach the control unit.
• The fault memory cannot be cleared.

Take an illuminated warning light seriously: as long as it is on, the protection provided by the airbags and seatbelt pretensioners cannot be relied on.

Which vehicles is the TK3T-14B321-AC fitted in?

The TK3T-14B321-AC is fitted in these vehicles: Ford Transit 7 ’14 (from 2014). This lets you compare the details with your vehicle.

The following vehicles are listed for this control unit:

• Ford Transit 7 ’14 (from 2014)

Compare the part number on the label of the removed unit with this page; this only confirms that you have the right unit in front of you. Also have the fault memory read out beforehand: only this finding shows whether the control unit is faulty or whether a connector or a cable is causing the fault.

For the same vehicles, we also repair control units with the part numbers RK3T-14B321-AB, BK2T-14B321-BE, BK2T-14B321-BF, BK3T-14B321-AB, BK3T-14B321-AC, BK3T-14B321-AD.

How does the repair of the TK3T-14B321-AC work?

First have the fault memory read out and enclose the log with the unit. Then disconnect the battery, only after that remove the control unit TK3T-14B321-AC, create a repair order online and send in the well-packed unit.

Airbag24 checks the unit on the test bench, replaces defective components and then tests its function. Checking, repairing and testing usually take 3–4 working days at Airbag24. After that, you receive your own unit back. If you would like the crash data deleted, get in touch with Airbag24 briefly before sending the unit in. 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 TK3T-14B321-AC get to Airbag24?

You send the control unit TK3T-14B321-AC to Airbag24 as a parcel, or you book a UPS collection for an extra charge. After the repair, the unit is sent back to you by UPS.

Put the printed repair order into the parcel and pack the control unit shockproof.