Theory Of Operation

WARNING: This page is about a different car, the 2020 Jeep Renegade. However, it is still accessible from the selected car via links, so may be relevant.

The Direct Injection system sprays fuel at a very high pressure directly into the combustion chamber. There are two sides to the fuel system, the low pressure (supply) side and high pressure (control) side. The high pressure side is monitored using feedback from the Fuel Rail Pressure Sensor (FRPS). The Powertrain Control Module (PCM) provides a shared 5-Volt supply and sensor ground to the FRP Sensor. There are two internal pressure sensors that provide signals to the PCM for redundancy. The PCM performs typical circuit diagnostics on each signal as well as a diagnostic that rationalizes the two signals.

NOTE:

The fuel system is under a constant pressure (even with engine off). Before servicing any fuel system hose, fitting or line, fuel system pressure must be released. Refer to FUEL SYSTEM PRESSURE RELEASE .