Most often, the fuel pump has direct battery voltage applied to it at all times, and the ground side control is duty cycled to control average voltage applied to the fuel pump. The command varies the duty cycle to the pump to control fuel pump speed, thereby controlling fuel pump pressure. This system utilizes a fuel pump driver module (FPDM) that the PCM sends a command to. With the electronic fuel returnless system, the powertrain control module (PCM) monitors fuel pressure via a fuel rail pressure sensor (FRPS). This article will deal with the electronic returnless system used on 2004 and newer F-150 trucks. ![]() ![]() One is a mechanical returnless system and the other is the electronic fuel returnless system. ![]() There are two types of returnless fuel systems. Ford has used “returnless” fuel systems for quite some time now, but we still get many calls regarding the theory of operation and diagnosis of low or high fuel pressure problems.
0 Comments
Leave a Reply. |