DTC C1386-02: Vacuum Sensor-Signal: General Description
Brake Boost Vacuum Pressure Sensor (BBVPS) is a sensor required for vehicles with ISG system. ISG is a system that temporarily suspends the vehicle's engine when it is in a signal waiting situation or when it is stationary, thereby improving fuel economy and curbing emissions.
A certain amount of vacuum pressure is required to maintain a stationary state when the engine is turned off, and the sensor checks the residual amount to determine whether to restart the engine.