Fuel Pump Control Unit: Description and Operation

FPDM (Fuel Pump Driver Module)





The FPDM (fuel pump driver module) is located under the rear RH (right-hand) seat and is attached to the underside of a cover plate. The fuel pump control module receives a power supply via the fuel pump relay in the auxiliary fuse box.

The ECM (engine control module) sends a PWM (pulse width modulation) signal to the FPDM (fuel pump driver module) from pin 20 of connector C0635 of the ECM (engine control module), the duty cycle of the signal determines the duty cycle of the pump. The ECM (engine control module) sets a target fuel pressure based on engine load. The target fuel pressure is maintained by using feedback from the fuel rail pressure sensor which is used to control the fuel pump via a closed loop PWM (pulse width modulation) signal. The PWM (pulse width modulation) signal to the pump represents half the ON time of the pump. If the ECM (engine control module) transmits a 50% on time the fuel pump control module drives the pump at 100%. If the ECM (engine control module) transmits a 5% ON time the fuel pump control module drives the pump at 10%. The fuel pump control module will only turn the fuel pump ON if it receives a valid signal between 4% and 50%. When the ECM (engine control module) requires the fuel pump to be turned OFF the ECM (engine control module) transmits a duty cycle signal of 75%.

The status of the FPDM (fuel pump driver module) is monitored by the ECM (engine control module) on connector C0635 pin 21. Any errors can be retrieved from the ECM (engine control module). The fuel pump control module cannot be interrogated for diagnostic purposes.

The ECM (engine control module) controls the FPDM (fuel pump driver module) in response to inputs from the fuel rail pressure sensor, MAP (manifold absolute pressure) and the MAF (mass air flow) /IAT (intake air temperature) sensor.

Harness Connector C2369 pin out details