B140A-00 - Crash seatbelt pretensioner (crash data stored) airbag control unit fault

What does error code B140A-00 mean?

Error code B140A-00 indicates a fault in the circuit of the crash‑belt pretensioner, accompanied by permanently stored crash data in the airbag control unit. This suggests either a past safety event or a critical hardware defect that has placed the system into a safety mode, preventing normal operation.

Technically speaking, the airbag control unit (ECU) detects a malfunction in the belt‑pretensioner system and locks itself due to the stored crash data. This condition is recorded as “permanent” in the fault memory.

This means the fault cannot be cleared simply by turning off the engine or disconnecting the battery. A professional diagnosis and targeted clearing of the memory after repair are absolutely necessary.

How can you recognize error B140A-00?

The primary and unmistakable symptom of error B140A-00 is the permanently illuminated airbag warning light on the instrument panel. Additionally, warning messages related to the restraint system may appear on the vehicle’s display. Another characteristic is that the error code cannot be cleared by simple means.

The airbag warning light remains continuously lit even after the engine starts, indicating that the entire airbag system is either non‑functional or only partially operational in case of a fault.

In particular, with the Peugeot 308 III, this error may occur sporadically. For example, the warning light might briefly illuminate upon starting the engine and then go out again—this is a strong indication of an intermittent contact issue in a connector.

What causes B140A-00?

The main cause of error code B140A-00 is almost always physical defects in the wiring and connectors of the belt‑pretensioner system, especially beneath the front seats. Loose connections, corrosion, or broken cables are typical culprits. Less frequently, a defective belt‑pretensioner sensor itself is responsible, manifesting as excessively high resistance in the circuit.

One of the most common sources of failure lies in the connectors under the vehicle seats. Frequent seat adjustments can mechanically stress the cables and connectors, leading to loose or corroded contacts. Similarly, damaged or kinked wires with compromised insulation can trigger the error.

Another potential cause is a defect within the belt‑pretensioner unit itself. In the workshop, this is diagnosed using a multimeter to measure resistance; excessively high resistance in the belt‑pretensioner circuit points to an internal component failure.

The “stored crash data” mentioned in the error code results from the detected fault or an actual incident. These data serve as a safeguard in the control unit, preventing further driving with a potentially defective safety system until proper inspection and repair have been carried out.

Which vehicles are affected by B140A-00?

Error code B140A-00 occurs predominantly in certain models from the Stellantis group. This includes newer Peugeot and Citroën models, as well as some Opel series. Professional repair is a proven solution for these specific vehicles.

At Airbag24, we have experience repairing error code B140A-00 for the following models:

Citroën: Berlingo III K9 (2018–2024), Berlingo Multispace III K9 (2018–2024)

Peugeot: 308 III (2021–2025), 308 III Facelift (from 2025)

Opel: Astra J (2009–2015)

How is error B140A-00 professionally repaired?

Professional repair of error B140A-00 proceeds in two steps: First, the physical cause—such as a faulty cable or a corroded connector—is fixed. Only after this hardware repair is completed is the airbag control unit read using specialized diagnostic equipment, and the permanently stored crash data are erased.

Following submission to Airbag24, repairs follow a well‑established procedure. Initially, the root cause of the fault is diagnosed directly on the vehicle. This includes visual inspection of connectors and cables, as well as resistance measurement of the belt‑pretensioner circuit.

Hardware repair then follows. Damaged wires are exposed, re‑insulated, and properly sealed with heat‑shrink tubing. Corroded or defective connectors are cleaned or replaced. In some cases, connections are soldered to enhance reliability. If the belt‑pretensioner unit itself is defective, it must be replaced.

Once the hardware issue has been resolved, the airbag control unit is connected via the OBD2 interface to professional diagnostic equipment. Technicians erase the permanently stored crash data and clear error code B140A-00. Finally, the functionality of the entire restraint system is thoroughly tested. We provide 2 years' statutory liability for defects on all repairs.