B1355 airbag control unit fault

What does error code B1355 mean?

Error code B1355 indicates a specific fault in the vehicle’s side airbag system. The airbag control unit (SRS module) has detected a malfunction in the circuit of the driver’s or passenger’s side airbag. This typically results in deactivation of the affected airbag and activation of the airbag warning light to alert the driver.

Technically, this DTC (Diagnostic Trouble Code) points to issues such as an open circuit, a short to ground or power, or an implausible resistance value in the side airbag ignition circuit. The control unit continuously performs self-tests, and whenever a measured value falls outside the predefined tolerance, error code B1355 is stored.

As a safety precaution, the system disables the affected airbag to prevent unintended deployment. This significantly compromises occupant protection during a side impact, making immediate diagnosis and repair essential.

How can you recognize error code B1355?

The primary and unmistakable symptom of error code B1355 is the permanently illuminated or flashing airbag warning light (SRS light) on the instrument panel. This light does not extinguish after the vehicle is started. In some vehicles, a text message may also appear on the display indicating a fault in the restraint system.

The airbag warning light is the control unit’s direct signal that a critical fault exists and the system is not fully operational. Under no circumstances should you ignore this warning.

Another telltale sign is that, during a diagnostic scan, the specific error code B1355 can be retrieved from the airbag control unit’s fault memory. Without a scan tool, it is impossible to accurately pinpoint the root cause.

What causes B1355?

The causes of error code B1355 are varied, ranging from simple contact issues to defects within the control unit itself. Common culprits include damaged cables or connectors near the seats, a faulty side airbag module, defective side‑impact sensors, or an internal hardware failure on the airbag control unit’s circuit board.

A very common cause is damaged wiring harnesses or loose electrical connections, especially beneath the front seats. Constant movement when adjusting the seats or objects left in the footwell can lead to cable breaks or corroded contacts.

The side airbag itself may also suffer an internal defect, resulting in an incorrect resistance reading in the ignition circuit. Similarly, the associated side‑impact sensors, which detect collisions, might be faulty or have poor connectivity with the control unit.

Finally, the fault could originate directly within the airbag control unit. Internal circuitry errors, defective electronic components, or corrupted memory areas on the circuit board can all trigger this error code.

B1355 often does not occur in isolation. Accompanying errors such as B1000, which indicates a general communication fault or internal control unit defect, or B1335 for a front‑impact sensor issue, can provide additional crucial clues about the underlying problem.

In which models does error code B1355 occur?

Although error code B1355 can appear across different manufacturers, workshop experience shows a particular prevalence in certain vehicle models. This error code has been diagnosed more frequently in Kia vehicles. Airbag24 offers specialized repairs for the affected control units.

At Airbag24, we repair airbag control units displaying error code B1355, including the following specifically affected model:

Kia: Mohave HM (model years 2008–2024)

How does professional repair work?

Professional repair focuses on restoring the removed airbag control unit. After submission to Airbag24, the device undergoes a thorough analysis, during which defective electronic components on the circuit board are identified and replaced. A final functional test then ensures full operability.

The process begins in the workshop with the proper removal of the airbag control unit. The unit is subsequently sent to us for repair.

At Airbag24, we conduct a systematic hardware-level inspection of the control unit. Our technicians analyze internal circuits, examine communication interfaces such as the CAN bus, and identify faulty components like resistors, capacitors, or integrated circuits (ICs).

Defective parts are carefully desoldered and replaced with new, high-quality components. If crash data was stored in memory following an accident, it is completely and securely erased as part of the repair process.

After the repair is completed, each control unit undergoes a comprehensive test on our test benches. This ensures that the original fault has been resolved and that the device communicates and functions flawlessly once again. We provide a 12-month warranty on every repair.