What is a Lexus NX NX250 airbag control unit?
The Lexus NX NX250 airbag control unit is the central safety unit that activates all occupant restraint systems in the event of an accident. It monitors sensors, stores crash data, and ensures the proper functioning of all airbag modules. This module is critical to vehicle safety and requires professional Lexus NX NX250 airbag control unit repair in the event of a failure.
This SRS (Supplemental Restraint System) control unit for the Lexus NX250, typically model years 2023 to 2025, is a highly complex electronic module.
It is responsible for coordinating the airbag systems in the vehicle, such as front, side and knee airbags, as well as seat belt pretensioners, and for precisely triggering them in an emergency.
The module communicates with other vehicle systems via the CAN bus and has a self-diagnosis function for permanent system monitoring.
Why is the Lexus NX NX250 airbag control unit defective?
A Lexus NX NX250 airbag control unit often fails because it stores crash data after an accident, necessitating repair or replacement. Electrical problems such as open circuits or faulty wiring are also common causes of failure. A precise diagnosis is therefore crucial before a Lexus NX NX250 airbag control unit is repaired at the workshop.
After a vehicle accident, the control unit stores indelible crash data, which requires professional repair or replacement of the module to restore full functionality of the SRS system.
Faulty cable connections, interruptions or short circuits in the airbag circuits are common causes that the control unit detects as errors and reports a failure.
Aging of the electronics, moisture ingress or overvoltage can also permanently damage the module, making a Lexus NX NX250 airbag control unit repair unavoidable.
Common error codes for Lexus NX NX250 airbag control unit repair
During Lexus NX NX250 airbag control unit repairs, specific error codes occur that directly indicate problems with the airbag control unit or its wiring. These codes are recognized by the control unit and usually indicate open circuits in the knee airbags (e.g., B1861, B1866), requiring precise diagnostics to identify and repair the defect.
- **B1861** → Open circuit in the knee airbag, driver side → Faulty cable connection or open circuit in the airbag control module or its wiring on the driver side.
- **B1866** → Open circuit in the knee airbag, passenger side → Analogous to B1861, affects the knee airbag circuit on the passenger side.
These B-codes are typical control unit error codes that are registered directly by the airbag control unit and do not relate to sensor errors or seat belt pretensioner problems.
An accurate diagnosis with a suitable OBD-II airbag diagnostic tool is essential to determine the cause of these errors before repair.
Before performing any work on the airbag system, the vehicle battery must be disconnected for at least two minutes to avoid safety risks.
What part numbers are available for the Lexus NX NX250 airbag control unit repair?
For Lexus NX NX250 airbag control unit repairs, only the original Lexus OEM part number 89170-78010 is currently available as a 100% verified and compatible airbag control unit. This number is specifically listed for Lexus NX models, including the NX250, and refers exclusively to the central airbag control unit.
Part number 89170-78010 is a genuine Lexus part number listed in official OEM parts catalogs for the NX series airbag control unit.
There are currently no other 100% verified alternative or supplier part numbers (e.g. from Bosch, Continental) for the Lexus NX250 airbag control unit.
Using the correct OEM part number is critical to a safe and functional Lexus NX NX250 airbag control unit repair and restoring vehicle safety.