Fuel Pump Driver Module
The FPDM is located under the floor near the fuel tank.
Operation of the LP fuel pump in the fuel tank mounted fuel pump module is regulated by the FPDM which is controlled by the PCM . The PCM sends a Pulse Width Modulation signal to the FPDM to control the operation of the LP fuel pump, in the fuel tank mounted fuel pump module.
The PWM signal from the PCM tells the FPDM the required speed for the LP fuel pump.
The FPDM only energizes the LP fuel pump if it receives a valid PWM signal, with a duty cycle of between 3.5% and 55%. To switch the LP fuel pump off, the PCM transmits a PWM signal with a duty cycle of 75%.
The FPDM has a switched power supply from the fuel pump relay, located in the Rear Junction Box (RJB).
The following conditions energize the fuel pump relay:
- Opening the driver door.
- Operating the ignition switch.
- Operating the ignition switch with applied brakes - Engine crank.
The FPDM supplies power to the LP fuel pump, in the fuel tank mounted fuel pump module through hardwired connections. The FPDM adjusts the power to control the speed of the fuel pump, thus the fuel pressure and flow in the fuel delivery pipe.
If there is a fault the PCM receives a diagnostic notification signal from the FPDM . Any DTC , produced by the FPDM are stored by the PCM . DTC s can be retrieved from the PCM using the JLR approved diagnostic equipment. The FPDM itself cannot be interrogated by the JLR approved diagnostic equipment.
For additional information, refer to: FUEL TANK AND LINES