Circuit Description
WARNING: This page is about a different car, the 2003 GMC Savana and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
The Fuel Rail Pressure (FRP) sensor is a pressure sensor. The Fuel Injector Control Module (FICM) supplies about 5 volts on the FRP sensor reference voltage circuit. The FICM also supplies a ground circuit and a signal circuit to the FRP sensor. When the fuel rail pressure is normal, the FRP signal voltage rises to near 2.5 volts. If the fuel rail pressure increases, the FRP signal voltage increases. The FICM monitors the FRP sensor voltage and communicates the data to the PCM by a dedicated Pulse Width Modulated (PWM) circuit. This DTC sets when the FRP sensor signal voltage is outside of the normal operating range of the sensor.