Description And Operation: Operation: Notes

WARNING: This page is about a different car, the 2023 Jaguar F-Pace and 2022 Jaguar F-Pace. However, it is still accessible from the selected car via links, so may be relevant.

The petrol fuel system uses a returnless fuel system. The LP fuel pump operation is regulated by the FPDM , which is controlled by the PCM. The FPDM regulates the fuel flow and pressure delivered to the engine mounted HP fuel pump by controls the operation of the LP fuel pump. The PCM uses a PWM signal to control the LP fuel pump output fuel flow and pressure.

The PCM uses the low fuel pressure sensor to make sure that the required fuel pressure is delivered by the LP fuel pump to the HP fuel pump.

The LP fuel pump assembly relay in the Rear Junction Box (RJB) supplies power to the FPDM. The LP fuel pump assembly relay is controlled by the BCM /GWM and it is active when the ignition is in all Power Modes except for Power Mode 0 (OFF). The PCM is connected to the BCM /GWM to receive a 'wake-up' message. In the event of an impact the Restraints Control Module (RCM) sends a crash signal to the BCM /GWM to disable the LP fuel pump assembly relay.

The 1 of the following conditions energizes the LP fuel pump assembly relay:

Opening the driver's door.
Operating the ignition switch.
Engine crank.

The PCM sends a PWM signal to the FPDM to control the speed for the LP fuel pump. The duty cycle of the PWM signal represents half the LP fuel pump speed. For example, if the PWM signal has a duty cycle of 50%, the FPDM drives the pump at 100%.

The FPDM will only energize the LP fuel pump if it receives a valid PWM signal, with an on duty cycle of between 4% and 50%. To switch the LP fuel pump OFF, the PCM transmits a PWM signal with a duty cycle of 75%.

The output pressure from the LP fuel pump will change with changes of engine demand and fuel temperature. The PWM monitors the input from the low fuel pressure sensor and adjusts the speed of the LP fuel pump as necessary to maintain a nominal output pressure of 4.5 bar (65.3 psi), except during engine startup. At engine startup the target pressure for the fuel delivery line is 6.3 bar (91.4 psi).

If the RCM outputs a crash signal to the BCM /GWM. The BCM /GWM de-energizes the LP fuel pump assembly relay to prevent any further fuel being pumped to the engine.

When the PCM does not detect pressure in the fuel delivery line, it stops, or refuses to start the engine and stores the appropriate DTC.

The PCM receives a monitoring signal from the FPDM. Any DTC produced by the FPDM are stored by the PCM.

The DTC can be retrieved from the PCM using the Jaguar Land Rover (JLR) approved diagnostic equipment. The FPDM itself cannot be interrogated by the JLR approved diagnostic equipment.

Fuel Level Sensor

Inside the fuel tank the 2 fuel level sensors 'A' and the fuel level sensor 'B', which output signals to the BCM /GWM for fuel tank fuel level.

The electrical output signal is dependant upon the amount of fuel remaining in each side of the fuel tank and the position of the float arms. The resistance is measured by the fuel level sensors and the information passed to the BCM /GWM which implements an anti-slosh function. The anti-slosh function monitors the signals and updates the fuel level signal to the instrument cluster at regular intervals. The anti-slosh prevents constant fuel gauge pointer movement caused by fuel movement in the fuel tank due to cornering or braking. A low level fuel warning indicator is incorporated in the IPC which illuminates when the fuel level in the tank falls below a predetermined level.

The fuel level sensor signals are converted in the BCM /GWM into High Speed (HS) CAN Human Machine Interface (HMI) systems bus and FlexRay messages.

The fuel level messages are used by the:

IPC for fuel gauge and fuel warning indicator operation.
PCM to store the DTC for mis-fire detection when the fuel level in the fuel tank is below a predetermined capacity.

North American Specification (NAS) and China market vehicles have a Diagnostic Module Tank Leakage (DMTL) pump for leak detection requirements. The DMTL has additional connections, hoses and pipes.

For additional information, refer to: EVAPORATIVE EMISSIONS - INGENIUM I6 3.0L PETROL (G2497702)