Airbag control unit with part number a6004940

What is the function of the airbag control unit a6004940?

The airbag control unit with part number a6004940 is the central safety module (SRS module) for the third-generation Ford Galaxy (Mk3). Its task is to continuously monitor signals from all relevant crash sensors as well as the seatbelt system, and in the event of an accident, to deploy the airbags and belt tensioners precisely and within seconds.

As the brain of the passive safety system, this electronic control unit is specifically designed for the vehicle architecture of the Ford Galaxy used from 2015 through the 2023 facelift. It continuously processes data from frontal, side, and acceleration sensors.

Based on this information, the control unit decides within milliseconds which restraint systems—such as front and side airbags or belt tensioners—must be activated to provide optimal protection for occupants during a collision.

Why does the control unit a6004940 fail?

The most common cause of failure for the control unit a6004940 is the storage of crash data after an accident or even a minor impact. This data locks the system and generates persistent error codes such as U3000 or U1A37-00. Other causes include internal electronic defects, such as faulty components on the circuit board.

Following a collision, the module stores irreversible “crash data.” This is a safety feature that locks the device to force a full-system diagnostic check. This lock prevents the airbags from being re‑deployed and triggers the warning light to illuminate.

The stored data manifests itself in specific, non‑erasable error codes. In particular, errors like “U3000 (control unit defect)” or “U1A37-00 (crash status telegram information)” directly indicate such stored crash entries as the root cause.

In addition to crash data, purely electronic defects can also occur on the circuit board. These include issues with wiring, connectors, or defective components such as capacitors, which may lead to complete system failure.

The control unit a6004940 is technically related to other units. Comparable functions can be found, for example, in Bosch control units with part numbers 0 285 001 679 or 0 285 010 223, which are used in similar vehicle architectures.

How do you recognize a defect in the control unit a6004940?

A defect in the control unit a6004940 is unmistakably indicated by the airbag warning light (SRS light) in the instrument cluster, which remains constantly illuminated or flashes sporadically. Additionally, error codes stored in the fault memory—especially after an accident—cannot be cleared using a diagnostic tool.

The primary and most obvious symptom is the active airbag warning light. It does not extinguish after starting the vehicle, signaling a serious malfunction in the restraint system that endangers occupant safety.

A diagnosis at a workshop reveals that entries stored in the fault memory cannot be erased. Attempts to reset the memory fail because the control unit is internally blocked by the stored crash data and no longer accepts commands.

In which models is a6004940 installed?

The airbag control unit with part number a6004940 was specifically developed for the third-generation Ford Galaxy (Mk3). It is used both in the original models from 2015 onward and in the revised facelift version from 2019, and is tailored exclusively for this vehicle series.

At Airbag24, repair of the control unit a6004940 is available for the entire third generation of the Ford Galaxy. Specifically, this includes the Ford Galaxy 3 models (2015–2019) as well as the Ford Galaxy 3 Facelift (2019–2023).

How does repair work at Airbag24?

Professional repair at Airbag24 focuses on the electronic restoration of the original control unit. Rather than purchasing a costly new unit, the stored crash data is carefully erased, and the module is restored to its factory condition. Any hardware defects are also addressed during the process.

For targeted repair, it is recommended to read out the fault memory before removing the control unit. After removal—typically located beneath the seat or center console—the unit is sent to Airbag24 for analysis and refurbishment.

Our technicians perform a thorough diagnosis and electronically restore the control unit. The core of the repair is safely erasing the crash data, thereby lifting the internal blockage. If components on the circuit board are defective, they are professionally replaced.

Following successful repair and a final functional test, the control unit is returned to you. We provide 2 years' statutory liability for defects on every repair performed.