Fuel Tank And Lines - INGENIUM I6 3.0L Petrol (G2342515): Operation: Notes
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 PCM uses a PWM signal to control the LP fuel pump output fuel flow and pressure. The FPDM :
- Regulates the fuel flow
- Pressure delivered to the engine mounted HP fuel pump by controlling the operation of the LP fuel pump.
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 pumps.
The FPDM is supplied with power through a fuel pump relay in the BCMB . The fuel pump relay is controlled by the BCM /GWM . The fuel pump relay is active when the ignition is in all Power Modes except for Power Mode 0 (ignition OFF). The PCM is connected to the BCM /GWM to receive a 'wake-up' message. In the event of an accident the RCM outputs a crash signal to the BCM /GWM to disable the LP fuel pump relay.
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. The FPDM adjusts the power to control the speed of the fuel pump and the pressure and flow in the fuel line.
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, when the PWM signal has a duty cycle of 50%, the FPDM drives the pump at 100%.
The FPDM only energizes the fuel pump when it receives a valid PWM signal, with an on duty cycle of between 4% and 50%. To switch the fuel pump OFF, the PCM transmits a PWM signal with a duty cycle of 75%.
The PCM :
- Monitors the input from the low fuel pressure sensor
- 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 start-up.
The output pressure from the LP fuel pump changes with changes of engine demand and fuel temperature. At engine start-up the target pressure for the fuel delivery line is 6.3 bar (91.4 psi).
When the RCM outputs a crash signal on a dedicated wire to the BCM /GWM . The BCM /GWM then de-energizes the fuel pump relay to prevent any further fuel being pumped to the engine.
When the PCM does not detect pressure in the fuel delivery line. The PCM stops, or refuses to start the engine and stores the appropriate Diagnostic Trouble Code (DTC).
The PCM receives a monitoring signal from the FPDM . Any DTC s produced by the FPDM are stored by the PCM .
DTC s can be retrieved from the PCM using an 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 of the fuel level sensors 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 measured resistance by the fuel level sensors and is transmitted 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 instrument cluster, 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) Controller Area Network (CAN) Human Machine Interface (HMI) systems bus messages. The fuel level messages are used by the:
- IPC for fuel gauge and fuel warning indicator operation.
- PCM stores DTC s for mis-fire detection when the fuel level in the fuel tank is below a predetermined capacity.
North American Specification and China Vehicles Only
NAS and China (CN6) vehicles have a DMTL pump for leak detection requirements which have additional:
- Connections
- Hoses
- Pipes.
For additional information, refer to: EVAPORATIVE EMISSIONS