590 airbag control unit fault

What does error code 590 mean in the airbag control unit?

Error code 590 indicates a specific issue with the passenger-side airbag’s second ignition circuit, technically referred to as “Passenger Airbag Trigger 2 – N132.” The On-Board Diagnostics system (OBD2) has detected an electrical fault in this trigger’s circuit. This suggests a defect in the airbag trigger itself, a break in the wiring, or an internal problem within the airbag control unit, thereby compromising the safety of the front passenger.

Technically speaking, the airbag control unit continuously monitors the resistance of all ignition circuits. If the measured value for trigger N132 deviates from the specified threshold—whether due to excessively high resistance (cable breakage) or excessively low resistance (short circuit)—error code 590 is stored in the fault memory, and the entire airbag system is deactivated as a precautionary measure.

This error code is critical for safety, as in the event of a crash, the passenger-side airbag may fail to deploy or deploy incorrectly. Immediate diagnosis and resolution of the issue are therefore essential to restore the system’s full protective functionality.

How can you recognize a fault in ignition circuit N132?

The primary and unmistakable symptom of error code 590 is the persistent illumination of the airbag warning light on the instrument panel. Additionally, the vehicle’s onboard computer may display a warning message related to the airbag system. During diagnostics, error code 590 will be explicitly recorded in the airbag control unit’s fault memory.

The airbag warning light fails to extinguish after starting the vehicle, signaling to the driver that there is a fault in the safety system and that it is not operational. Other vehicle functions are typically unaffected, but passive safety is significantly compromised.

In some cases, the control unit may become inaccessible via the OBD2 interface due to an internal fault. While this complicates diagnosis, it often points directly to a defect within the control unit itself.

What are the most common causes of error code 590?

The most frequent cause of error code 590 is a malfunction in the passenger-side airbag’s ignition circuit. This includes a defective airbag trigger (N132), a broken cable, a short circuit in the supply line, or a poor connector contact. An internal defect within the airbag control unit itself can also trigger this error, often due to aging or moisture exposure.

A faulty airbag trigger is a common culprit. The pyrotechnic igniter inside may alter its electrical properties over time or due to vibrations, which the control unit interprets as a fault.

Another potential source of failure is the wiring. A broken cable or short circuit between the control unit and the airbag module—often caused by mechanical stress such as seat adjustments or vibrations—will immediately result in an error message. Corroded or loose connector contacts are also typical causes.

Finally, the airbag control unit itself may suffer from an internal hardware defect. Electronic components on the circuit board responsible for activating trigger N132 can fail due to voltage spikes, moisture, or simply material fatigue.

Which vehicles are affected by error code 590?

Error code 590 frequently occurs in specific models from the VAG Group. At Airbag24, we specialize in repairing this error code, particularly for Audi vehicles, with extensive expertise across the following model series.

Our technicians have comprehensive experience in diagnosing and repairing this fault in the following models:

Audi SQ5 FY (model years 2017–2020) Audi SQ5 FY Facelift (model years 2020–2024)

How is the airbag control unit repaired?

Professional repair of error code 590 requires meticulous component-level analysis. After sending the removed airbag control unit to Airbag24, a thorough electronic inspection is performed. Defective components on the circuit board are identified and expertly replaced to restore full functionality of ignition circuit N132. Final tests ensure proper operation before the unit is prepared for shipment.

The process begins with a careful incoming inspection of the submitted control unit. First, attempts are made to reproduce the fault while the unit remains disassembled on a specialized test bench, enabling precise localization of the root cause.

Subsequently, Airbag24 technicians open the housing and conduct visual inspections along with electronic measurements on relevant components. Defective parts—such as resistors, capacitors, or driver ICs responsible for ignition circuit N132—are desoldered and replaced with new, high-quality components.

After component-level repair, the control unit undergoes an extensive functional test. This includes simulating communication with other control units and verifying the proper operation of all ignition circuits. Only after a successful test is the unit approved for return shipment.

Repair is a sustainable and cost-effective alternative to expensive new purchases and does not require subsequent coding or programming in the vehicle. We offer 2 years' statutory liability for defects on all repairs.