Fuel Pump Driver Module (FPDM)

WARNING: This page is about a different car, the 2015 Land Rover LR2, 2014 Land Rover LR2, and 2013 Land Rover LR2. However, it is still accessible from the selected car via links, so may be relevant.

The FPDM is located in the LH rear of the luggage compartment. The module is attached to a bracket suspension turret and secured with two bolts.

The operation of the fuel pump 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 PWM output.

The FPDM is powered by a fused supply from the fuel pump relay in the BJB. The fuel pump relay is energized when the driver's door is opened or power mode 9 engine crank is initiated using the stop/start button. The FPDM supplies power to the fuel pump and adjusts the frequency of the PWM power output to control the speed of the fuel pump and consequently the pressure and flow of fuel in the fuel delivery line to the HP fuel pump.

The PWM signal from the ECM tells the FPDM the required speed for the fuel pump output. The on time of the PWM signal represents half of the fuel pump speed, for example, if the PWM signal on time is 50%, then the fuel pump is run 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 is controlled in line with changes of engine demand and temperature. The ECM monitors the input from the LP fuel sensor and adjusts the fuel pump output as required to maintain a nominal output pressure of 4.5 Bar (65.3 lbf/in² ), except during engine start-up. At engine start-up the target pressure for the fuel delivery line is 6.3 Bar (91 lbf/in² ).

If the SRS (supplemental restraint system) module outputs a crash signal on the high speed CAN (controller area network) bus, the ECM de-energizes the fuel pump relay to prevent any further fuel being pumped to the engine compartment.

If the ECM does not detect a pressure signal from the LP fuel sensor, it will stop the engine and will not allow an engine re-start. A DTC (diagnostic trouble code) will be recorded in the ECM.