The Engine Control Module (ECM) monitors the fuel pressure because it is very important to modulate the injector pulse width. When there is higher fuel pressure, less pulse width is required to obtain the same level of fuel. Besides, fuel pressure monitoring prevents damage to the injection system components.
When the DTCP0192 OBDII code is stored, it is due to the Fuel Rail Pressure Sensor (FRP) input signal is below the programmed limit for some time. The reasons may be electrical or mechanical failures.