Fuel Pump Driver Module (FPDM)
The FPDM is attached to a bracket and secured by two nuts to the right side D-pillar, behind the right side seat bolster.
The fuel pump operation is regulated by the FPDM which is controlled by the ECM. The FPDM regulates the flow and pressure supplied by controlling the operation of the fuel pump using a Pulse Width Modulation (PWM) output.
The FPDM is powered by a supply from the fuel pump relay in the Rear Junction Box (RJB). The fuel pump relay is energized on opening the driver's door, pressing the start button only or pressing the start button and the footbrake (which initiates engine cranking). The FPDM supplies power to the fuel pump, and adjusts the power to control the speed of the fuel pump and the pressure and flow in the fuel delivery line.
A PWM signal from the ECM tells the FPDM the required speed for the fuel pump. The on time of the PWM signal represents half the fuel pump speed, for example; if the PWM signal has an on time of 50%, the FPDM drives the pump at 100%.
The FPDM will only energize the fuel pump if it receives a valid PWM signal, with an on time of between 4% and 50%. To switch the fuel pump off, the ECM transmits a PWM signal with an on time of 75%.
The output pressure from the fuel pump will change with changes of engine demand and fuel temperature. The ECM monitors the input from the fuel Low Pressure (LP) sensor and adjusts the speed of the fuel pump as necessary to maintain a nominal output pressure of 450 kPa (4.5 bar; 65.3 lbf/in2 ), except during engine startup. At engine start-up the target pressure for the fuel delivery line is 630 kPa (6.3 bar; 91.4lbf/in2 ).
If the Restraints Control Module (RCM) outputs a crash signal on the high speed Controller Area Network (CAN) powertrain systems bus, the Body Control Module/Gateway Module (BCM/GWM) de-energizes the fuel pump relay to prevent any further fuel being pumped to the engine.
If the ECM does not detect pressure in the fuel delivery line, it stops, or refuses to start the engine and stores the appropriate Diagnostic Trouble Code (DTC).
The ECM receives a monitoring signal from the FPDM. Any DTC's produced by the FPDM are stored by the ECM.
DTC's can be retrieved from the ECM using an approved Jaguar diagnostic system. The FPDM itself cannot be interrogated by the approved Jaguar diagnostic system.