FRP and FRT Sensor PWM Circuits

The fuel rail pressure and temperature sensor information is required by the PCM for fuel trim adjustment. The PCM does not have the ability to supply and monitor the FRP and FRT sensors. The FICM performs this task by supplying the FRP and FRT sensors a 5 volt reference, low reference and signal circuit. The signal voltage of the FRP and FRT sensors are converted into independent PWM signals. The PWM signals are sent to the PCM through dedicated circuits. The PCM converts the PWM signals into pressure and temperature values. The FICM also performs diagnosis of the FRP and FRT circuits as well as internal FICM diagnostic information. The FICM diagnostic information is converted into a PWM signal. The FICM PWM signal is sent to the PCM through a dedicated circuit.