B024 airbag control unit fault

What does error code B024 in the airbag control unit indicate?

Error code B024 signifies a critical internal fault in the airbag control unit (SRS). During its self-test, the unit detected an irreparable defect in its hardware or internal software logic. As a result, for safety reasons, the entire airbag system is deactivated, and the airbag warning light remains steadily illuminated.

Technically speaking, B024 is a standardized diagnostic trouble code (DTC) stored in the control unit’s fault memory. Upon system startup, the control unit performs a self-check; if it detects irregularities—such as issues with the power supply, memory chips, or the microprocessor—the error is triggered.

The consequence is immediate deactivation of the system. The control unit enters a safety mode to prevent unintended airbag deployment. From that point onward, the protective function of the SRS system is no longer guaranteed.

How can you recognize error B024?

The primary and unmistakable symptom of error B024 is the permanently illuminated airbag warning light on the instrument panel. It does not turn off after the vehicle is started. Often, the control unit also becomes inaccessible via diagnostic equipment, complicating further troubleshooting since communication is blocked.

The most noticeable sign is the continuously lit SRS warning light, clearly indicating to the driver that a serious fault exists in the restraint system and that the airbags will not deploy in the event of a crash.

Another common feature is that workshops are unable to establish communication with the airbag control unit using their diagnostic tools. The unit no longer responds to queries, directly pointing to a complete internal failure.

What causes error code B024?

The main cause of B024 is internal electronic damage within the airbag control unit itself. This includes component failures due to aging, damage from voltage spikes or water ingress, as well as crash data stored after an accident that locks the unit. Less frequently, external wiring issues may also trigger this error.

First and foremost are internal hardware defects. Damaged components such as capacitors, resistors, or integrated circuits (ICs) on the circuit board are a frequent source of failure. Cold solder joints or corrosion following water damage can likewise lead to this error.

Problems with the power supply—whether under- or over-voltage—can permanently harm the control unit’s sensitive electronics and trigger B024.

A further typical cause involves crash data stored within the control unit. After a collision, the unit locks itself and reports an internal fault until this data is professionally reset.

Occasionally, error B024 may occur alongside other codes, such as B1000 (replace control unit), B1010 or B1315 (faulty power supply), 65535 (control unit defective), or sensor errors 0666 and 0667.

Which vehicles are affected by B024?

Based on experience, error code B024 occurs in specific vehicle models from Ford, Daewoo, and Rover. Particularly common are the Ford Transit Mk2, the Daewoo Lanos T150, and the Rover Range Rover equipped with the 2.5 TD engine.

At Airbag24, we repair error code B024 for the following models where this defect is prevalent:

Ford: Transit Mk2

Daewoo: Lanos T150 (model years 1997–2004)

Rover: Range Rover 2.5 TD

How is error B024 professionally repaired?

A professional repair of error B024 focuses on restoring the removed airbag control unit. At Airbag24, the process includes a detailed analysis of the circuit board, replacement of faulty electronic components, secure erasure of crash data, and a final functional test to verify successful repair.

After submitting the control unit to Airbag24, it undergoes a standardized repair procedure. First, the B024 error is verified on a test bench using diagnostic equipment. This is followed by a visual inspection of the circuit board for obvious damage.

The core of the repair lies in component-level restoration. Our technicians identify and replace defective hardware parts, such as resistors, processors, or memory chips. If crash data is present, it is erased from the EEPROM memory, returning the unit to its original factory condition.

Following repair, each control unit undergoes rigorous testing to ensure flawless operation of all system components. Of course, every repaired unit comes with 2 years' statutory liability for defects.