Theory Of Operation
WARNING: This page is about a different car, the 2019 RAM 3500 HD and 2019 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The Fuel Rail Pressure Sensor (FRPS) provides a primary fuel pressure signal to the Powertrain Control Module (PCM) on the FRPS Signal 1 circuit. The FRPS also provides a secondary fuel pressure sensor signal on the FRPS signal 2 circuit. The FRPS signal voltage changes based on the pressure in the Fuel Rail. The PCM will detect a high signal voltage during high rail pressure conditions. The PCM will detect a low signal voltage during low rail pressure conditions. During this time the customer may experience a torque reduction and/or speed limiter.