Technician A says that most fuel injection systems use the PCM to control the pulsing of the fuel injectors. Technician B says that most fuel injection systems use the PCM to control the operation of the fuel pump relay. Which technician is correct?

The correct answer is: Both Techs PCM.

Explanation:

The fuel control system electronically uses a completely different mechanism for pressure control. In this system, the PCM controls the rail pressure by modulating the activation of the pump, that is to say that it activates and deactivates the pump to maintain a pressure level according to the load in which the engine is, for this you need to know exactly the fuel pressure and its temperature, so it will incorporate 2 sensors for this purpose.

Basically, it is a system that activates and deactivates the fuel pump with the help of a DRIVER module, which directly controls the PCM, this module is called FPDM, this module controls the voltage and current flowing through the pump.

To know the pressure of the rail, a pressure sensor is used which is in charge of permanently sending a level of tension that changes with the pressure, this sensor is called FRP, while measuring the pressure of the rail is evaluated the fuel temperature in the rail, for this a sensor of the NTC type (Negative temperature coefficient), called EFT, is incorporated.

All this information is used to correctly calculate the pressure and thus have an efficient operation, reaching even lower levels of contamination.

Mechanically, the system incorporates a Damper, to avoid pressure peaks every time the injectors are opened and closed.

answer; i do believe that the correct answer is (d) referrals from

answer; i believe both technician (a) and (b) are correct; /// good luck