Airbag control unit with part number YS6T-14B056-BC

What is the function of the airbag control unit YS6T-14B056-BC?

The airbag control unit YS6T-14B056-BC, often identified by the manufacturer’s part number Bosch 0 285 001 349, serves as the central control module for the occupant restraint system (SRS) in vehicles such as the Ford Fiesta 3 ’89. It processes data from crash sensors and determines whether to deploy airbags and seatbelt pretensioners, thereby protecting vehicle occupants during a collision.

As a classic SRS control unit (Supplemental Restraint System), this component is responsible for monitoring and activating all safety-related restraint systems. It continuously communicates with the vehicle’s sensors to detect collisions and assess their severity.

In the event of an accident, the unit sends ignition signals within milliseconds to the appropriate pyrotechnic charges of the airbags and seatbelt pretensioners. At the same time, it records so‑called crash data, which documents the details of the accident and locks the system until professional repair is performed.

Why does the YS6T-14B056-BC control unit fail?

The most common cause of failure for the YS6T-14B056-BC control unit is the storage of crash data after a collision, resulting in permanent system lockout (error code B1231). Similarly prevalent are internal electronic faults that prevent communication with the unit or trigger error code B1342 (control unit defective).

Following an accident, the control unit is software‑locked by writing crash data into its internal memory (EEPROM/Flash). This lock can only be lifted through specialized repair and causes the airbag warning light to remain illuminated permanently.

Another frequent source of failure is electronic component damage. In older models like the Ford Fiesta Mk3, aging and vibrations often lead to cold solder joints on connectors or critical components. Defects in the power supply, driver stages for the ignition circuits (squib drivers), or the communication interface (K‑Line) are also typical issues.

Rarely, moisture‑induced corrosion on the circuit board can also cause malfunctions. Provided these damages are not too severe, they can usually be rectified through professional refurbishment.

How do you recognize a defect in the YS6T-14B056-BC control unit?

A defect in the airbag control unit YS6T-14B056-BC primarily manifests as a persistently illuminated airbag warning light on the instrument cluster. Additional indicators include specific fault codes such as B1231 (crash data detected) or B1342 (control unit defective), along with a complete loss of communication between the diagnostic tool and the control unit.

The clearest symptom is the red airbag warning light that remains active on the dashboard after the engine starts. It does not extinguish, indicating that the entire restraint system is disabled and will not function in the event of a crash.

In the workshop, the defect often becomes apparent when access to the control unit via a diagnostic scanner is no longer possible. The unit fails to respond to queries, pointing to a serious internal electronic fault.

When fault codes are read, entries such as “crash data stored” or “internal control unit defect” provide clear evidence. These errors cannot be cleared using standard workshop tools and require specialized electronics repair.

In which models is the YS6T-14B056-BC control unit installed?

The airbag control unit with part number YS6T-14B056-BC is predominantly used in older Ford models. Its most common application is in the third‑generation Ford Fiesta (Mk3). At Airbag24, we specialize in repairing this specific control unit for the vehicles listed here.

The part number YS6T-14B056-BC is exclusive to Ford vehicles. Airbag24 offers repairs for the following model:

Ford: Fiesta 3 ’89 (model years 1989–1996)

It is essential to verify the part number printed on the control unit—both YS6T-14B056-BC and the frequently associated manufacturer’s number, such as Bosch 0 285 001 349—before shipping to ensure correct identification and proper repair.

How is the YS6T-14B056-BC control unit professionally repaired?

Professional repair of the YS6T-14B056-BC at Airbag24 includes a thorough initial diagnosis, targeted deletion of crash data from memory, and restoration of any defective electronic components. Following a final functional test on the test bench, you receive a fully operational control unit backed by 2 years’ statutory liability for defects.

After sending the removed control unit to Airbag24, a comprehensive inspection is first conducted. This involves reading fault memories and examining the circuit board for visible damage, such as corrosion or signs of burning.

The core of the repair process is divided into two stages. First, the crash data stored in the internal memory (EEPROM/Flash) is erased by reading, modifying, and rewriting the data record, thereby lifting the software-based lock on the control unit.

If an additional electronic fault is present, the defective components on the circuit board are identified and replaced. This typically involves repairing the power supply, the ignition circuit drivers, or addressing cold solder joints.

Finally, the refurbished control unit undergoes a comprehensive functional test on a specialized test bench. Only after passing this test is the unit approved for return shipment. We provide 2 years' statutory liability for defects on all repairs.