Fuel pump

Fig 1: Fuel Level Sensor (Gasoline/Diesel)

Courtesy of VOLVO CARS OF NORTH AMERICA.

The fuel pump (FP) is located on the inside of the fuel tank on the right-hand side. The pump is checked by the central electronic module (CEM) which operates a relay. This relay controls the power supply to the pump and is directly connected to the central electronic module (CEM).

The central electronic module (CEM) uses the controller area network (CAN) to communicate with the engine control module (ECM) to control the fuel pump (FP). There is also a hardwire connection between the engine control module (ECM) and the central electronic module (CEM). This is used to transmit a pulsed signal to operate the fuel pump (FP). This allows the pump to function if there is a fault in the controller area network (CAN).

The central electronic module (CEM) also communicates with the supplemental restraint system (SRS) module via the controller area network (CAN). In the event of a collision, the supplemental restraint system module (SRS) transmits data and the central electronic module (CEM) shuts off the fuel pump (FP).

There are diagnostics for the input signal from the engine control module (ECM) and for the relay for the fuel pump (FP).