Fuel Pump Control Module

Courtesy of VOLVO CARS CORPORATION

The fuel pump control module is called the PEM (Pump Electronic Module). The function of the PEM is to supply the fuel pump with voltage and to control the power output of the fuel pump. When the power output of the pump is changed the fuel pressure is also changed.

The pump electronic module (PEM) is supplied with battery voltage by the fuel pump (FP) relay and is grounded in the car body. The fuel pump (FP) relay is controlled by the central electronic module (CEM) when requested by the engine control module (ECM).

The engine cannot be started if the power supply to the fuel pump control module is faulty because the fuel pump will not then be powered.

The pump electronic module (PEM) is controlled by the engine control module (ECM) via serial communication. The pump electronic module (PEM) then controls the fuel pump by transmitting pulse width modulated (PWM) voltage on the ground lead for the fuel pump. This means that the voltage drop across the pump changes, and with it the output of the fuel pump. See also: FUNCTION  

There are no diagnostics for the fuel pump control module. The engine control module (ECM) has diagnostics for fuel pressure regulation and the associated components. See also: FUEL PRESSURE REGULATION, DIAGNOSTICS

The pulse width modulated (PWM) signal from the engine control module (ECM) to the pump electronic module (PEM) can be read off using the diagnostic tool.

The fuel pump control module is on the outside on the right-hand side of the fuel tank.