Solenoid, Fuel Quantity: Operation
WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
- The Fuel Quantity Solenoid (FQS) controls the quantity of fuel entering the High Pressure Fuel Injection Pump (HPFIP) internal pumping chambers. The PCM determines the fuel pressure needs of the fuel injection system based upon internal programming and numerous sensor inputs. The Powertrain Control Module (PCM) then controls the FQS as needed to maintain the appropriate injection system operating pressure by directing fuel pressurized by the pump into either the high pressure fuel circuit or the fuel return circuit.
- The FQS and control circuits are continuously monitored by the PCM. If the PCM detects a problem in any monitored circuit, it will store a Diagnostic Trouble Code (DTC) in its memory circuits. Such a DTC can be retrieved from the PCM through the Controller Area Network (CAN) data bus using a diagnostic scan tool connected to the Data Link Connector (DLC).
- The FQS and the hard wired circuits between the solenoid and the PCM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the fuel quantity solenoid or the electronic controls or communication between other modules and devices that provide some features of the fuel injection system. The most reliable, efficient, and accurate means to diagnose the fuel quantity solenoid or the electronic controls and communication related to fuel injection system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.