Airbag control unit with part number CK4T-14B321-DE

What does the airbag control unit CK4T-14B321-DE do?

In Ford vehicles, the airbag control unit CK4T-14B321-DE takes over control of the restraint system (SRS). From the signals of the crash sensors, it calculates in a collision which airbags and seatbelt pretensioners to trigger, within milliseconds. During continuous operation it monitors all components and reports faults via the airbag warning light.

The unit checks wiring, sensors and seatbelt pretensioners for proper function. If it detects a deviation, it creates a fault entry in its memory.

After an accident the control unit stores crash data and locks itself.

Why does the control unit CK4T-14B321-DE fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered at all. A normal diagnostic tool cannot delete it. Other causes are ageing electronics, cold solder joints, moisture and corrosion, and voltage spikes.

Crash data is a cause that is not visible from the outside. The vehicle may continue to drive unchanged after the event.

Further causes include, among others:

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

Airbag24 removes the stored crash data during the repair.

How can you tell that the CK4T-14B321-DE is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently when there is a defect in the CK4T-14B321-DE. Accompanying this, an error message appears in the instrument cluster, there is no connection to the diagnostic tool, and the fault memory cannot be cleared. In an emergency, the airbags and seatbelt pretensioners may then fail to deploy.

This warning light is the visible part of the system's self-monitoring. It shows that the control unit has detected a deviation.

A missing connection to the diagnostic tool is also a finding that you should have clarified.

Which vehicles is the CK4T-14B321-DE fitted in?

The control unit CK4T-14B321-DE is fitted by Ford in this vehicle: Ford Transit 7 ’14 (from 2014).

The assignment of this part number is as follows.

• Ford Transit 7 ’14 (from 2014)

Matching the part number on the label of the removed unit confirms that it is the correct part. Whether the control unit is defective or a plug or cable is the cause is shown only by the fault memory read-out. For this reason, carry out this step before removal.

For the same vehicles, we also repair control units with the part numbers BK2T-14B321-BF, BK3T-14B321-AC, DT1T-14B321-DF, KT1T-14B321-KD, LK4Z-14B321-C, LK4Z-14B321-E.

How does the repair of the CK4T-14B321-DE work?

First have the fault memory read out and attach the log. Then disconnect the battery, remove the control unit CK4T-14B321-DE, and only then create the repair order online. The testing, repair and function test at Airbag24 usually take 3–4 working days.

Pack the unit well and send it in. Airbag24 tests it on the test bench, replaces defective components, deletes crash data and carries out a function test.

The own unit then goes back 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 CK4T-14B321-DE get to Airbag24?

You send the control unit CK4T-14B321-DE as a parcel or arrange a UPS collection for an extra charge. Airbag24 sends the repaired unit back to you by UPS.

Pack the printed repair order with the unit and pack the control unit shock-proof.