Airbag control unit with part number 212388104

What is the function of Airbag Control Unit 212388104?

The Airbag Control Unit 212388104, manufactured by TRW, serves as the central control unit for the entire Safety Restraint System (SRS), primarily in the Peugeot 107. It continuously analyzes data from crash sensors and, in the event of an accident, precisely deploys airbags and pretensioners to protect occupants.

As the brain of the restraint system, this control unit is responsible for monitoring all safety‑related components. It processes sensor signals and ensures the system remains fully operational at all times. A malfunction in this unit results in complete deactivation of the airbag system.

The device’s primary task is the precise evaluation of acceleration and deceleration values. Only during an actual collision is the ignition pulse released to the pyrotechnic charges, preventing false activations under normal operating conditions. Failure of this component not only compromises vehicle safety but may also lead to failure during the mandatory technical inspection (TÜV).

Why does Control Unit 212388104 fail?

Malfunctions of Control Unit 212388104 often occur without any prior accident and are usually due to internal electronic faults. Common causes include defective internal components that generate persistent error messages, or stored crash data that locks the control unit and cannot be cleared via OBD.

A typical fault pattern is the B1000 code stored in the fault memory, or a message indicating “internal component failure.” This points to a defect on the circuit board and prevents proper operation of the entire airbag system.

Following an accident, crash data is permanently recorded in the control unit’s memory. This lock cannot be removed using standard diagnostic tools and requires specialized electronic repair. In some cases, the vehicle identification number (VIN) may also disappear from the device’s memory after a crash.

Additional failure causes can include external factors such as undervoltage from a faulty battery or alternator, short circuits in the vehicle’s electrical system, cable breaks—especially beneath the seats due to dirt or spilled liquids—or water damage leading to corrosion.

The control unit is also known under alternative part numbers 212388-103, 212388-105, 212388-110, 89170-0H050, and 6546F6/F7, which are often compatible and exhibit similar fault patterns.

How do you recognize a defect in Control Unit 212388104?

A defective Airbag Control Unit 212388104 almost always manifests as a constantly illuminated or intermittently flashing airbag warning light on the instrument cluster. Communication via the OBD interface is frequently lost, and non‑erasable fault codes remain stored in the fault memory.

The most obvious sign is the active airbag warning light (SRS light), clearly indicating to the driver that the safety system is not functioning properly.

Another clear symptom occurs when a workshop’s diagnostic tool cannot establish communication with the airbag control unit. The device fails to respond to queries, making further troubleshooting within the system difficult or impossible.

Even if communication is possible, stored fault codes—such as the generic B1000 code for an internal fault—cannot be permanently erased; they reappear immediately after attempts to clear them.

Important note: Before attributing the issue to the control unit itself, peripheral components like seat occupancy mats, connectors, and wiring should be thoroughly inspected. Using airbag simulators or resistors to bypass the system is extremely dangerous and will result in loss of vehicle operating approval.

In which vehicles is part number 212388104 installed?

Part number 212388104 is primarily used in various model series of the Peugeot 107. Due to platform similarities, this control unit is also employed in the identical Citroën C1. Repair services provided by Airbag24 restore full functionality for these models.

At Airbag24, we repair this control unit for the following specific models:

Peugeot: 107 (Generation I, 2005–2009), 107 (First Facelift, 2009–2012), 107 (Second Facelift, 2012–2014)

Citroën: C1 (corresponding model years)

How does repair proceed at Airbag24?

Repair of Control Unit 212388104 at Airbag24 involves electronic refurbishment, addressing internal defects and erasing crash data. Upon submission, the unit undergoes analysis at the circuit board level, defective components are replaced, and the software is reset, restoring full functionality.

The process ideally begins with a definitive diagnosis at a specialized workshop confirming that the defect lies within the control unit itself. The removed unit, typically located beneath the driver’s seat, is then securely packaged and shipped to Airbag24. An excerpt of the fault log is highly helpful in this stage.

At Airbag24, our technicians perform a detailed electronic analysis, identifying short circuits, voltage issues, and defective microcomponents on the circuit board.

The actual repair involves eliminating the root cause of the fault. This may include replacing components, reprogramming the memory, or professionally erasing crash data—even if the unit is no longer accessible via OBD.

Following successful restoration and a final functional test, the control unit is returned to you. In some cases, only a one-time clearing of the vehicle’s fault memory is required. We provide 2 years' statutory liability for defects on all repairs.

Is it worth repairing 212388104?

Repairing the airbag control unit 212388104 is the most cost-effective solution. You save significantly compared to an expensive new part, which can cost up to 800 euros. Additionally, there’s no need for time-consuming re-coding, and you receive 2 years’ statutory liability for defects on the work performed.

A key advantage is the cost savings. While a new part from the manufacturer can range from 750 to 800 euros according to available data, repair offers a much more affordable alternative that restores full functionality.

Since your original control unit is repaired and retains its vehicle-specific configuration, no costly and time-consuming reprogramming or coding at an authorized dealer is required after reinstallation.