Fuel Pump Driver Module
Vehicles Without Auxiliary Fuel Filter Assembly
On vehicles without auxiliary fuel filter assembly the Fuel Pump Driver Module (FPDM) is located behind the right second row seat. The FPDM is attached to a bracket and secured by 2 nuts to the rear underfloor reinforcement panel.
The fuel pump operation is regulated by the FPDM which is controlled by the Powertrain Control Module (PCM) using a Pulse Width Modulation (PWM) output signal.
The FPDM has a switched power supply from the fuel pump relay, located in the Rear Junction Box (RJB).
The following conditions will energize the fuel pump relay:
- Opening the driver door.
- Operating the ignition switch.
- Operating the ignition switch with applied brakes.
The FPDM supplies power to the fuel pump via 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 line.
A PWM signal from the PCM tells the FPDM the required speed for the Low Pressure (LP) 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 LP fuel pump if it receives a valid PWM signal, with an on time of between 4% and 50%. To switch the LP fuel pump off, the PCM transmits a PWM signal with an on time of 75%.
The output pressure from the LP fuel pump will change with changes of engine demand and fuel temperature. The PCM calibrates the engine and fuel demands then sends a PWM signal to the FPDM to adjust the speed of the LP fuel pump as necessary.
Vehicles With Auxiliary Fuel Pump
On vehicles with auxiliary fuel pump the Fuel Pump Driver Module (FPDM) is located front left wheel arch behind the front left wheel. The FPDM is secured to the side member reinforcement panel with 2 nuts.
The FPDM regulates the operation of the auxiliary fuel pump located in the engine compartment. The FPDM regulates the flow supplied by controlling the operation of the auxiliary fuel pump via a hardwired connection. The FPDM is controlled by the Powertrain Control Module (PCM) using a Pulse Width Modulation (PWM) output signal.
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 door, pressing the stop/start switch only or pressing the stop/start switch and the footbrake (which initiates engine cranking).
The FPDM supplies power to the auxiliary fuel pump to maintain pressure and flow in the fuel delivery line to the High Pressure (HP) fuel pump.
If the Restraints Control Module (RCM) outputs a crash signal to the Body Control Module/Gateway Module (BCM/GWM). The BCM/GWM de-energizes the fuel pump relay to prevent any further fuel being pumped to the engine.
The PCM receives a monitoring signal from the FPDM. Any Diagnostic Trouble Codes (DTC) produced by the FPDM are stored by the PCM.
DTCs can be retrieved from the PCM using an approved Jaguar Land Rover (JLR) approved diagnostic equipment. The FPDM itself cannot be interrogated by the JLR approved diagnostic equipment.