Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
System Outline
* In the pre-collision seat belt system (PSB), the seat belt is retracted by a motor when it receives a signal from the pre-collision sensor (Millimeter wave radar sensor + distance control ECU) and skid control ECU (w/ vehicle dynamics integrated management) or skid control ECU with actuator (w/o vehicle dynamics integrated management). It does this to optimize the restraint performance.
* The skid control ECU (w/ vehicle dynamics integrated management) or skid control ECU with actuator (w/o vehicle dynamics integrated management) sends trigger signals to seat belt control ECU through CAN communication when it detects certain vehicle conditions such as a spin, under-steer or sudden braking. The seat belt control ECU activates the PSB upon receiving these signals.
* The pre-collision sensor detects an on-coming vehicle or an object on the road ahead with a millimeter wave radar and determines in advance whether a collision is unavoidable from information from the distance control ECU, such as the position, speed and on coming route of the object. The distance control ECU then sends signals to the seat belt control ECU through CAN communication to activate the PSB motor and retract the seat belts before a crash. This function even works when the vehicle speed is 0 km/h if the conditions are right.
* When the pre-collision system (PCS) experiences a failure, 'CHECK PCS' is displayed on the multi information display in the meter. The exclusive PCS warning lamp will also then be lit up. When the system is not available, such as when there is dirt on the radar, 'PCS DISABLED NOW' will be displayed and the warning lamp blinks.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.