Which component activates the electric boost pump when fuel pressure drops?

The electric boost pump is activated by the 10 PSI pressure switch when fuel pressure drops below a specific threshold. This component is designed to monitor the fuel pressure in the system and ensures adequate fuel delivery to the engine. If the pressure falls to 10 PSI, it signals the boost pump to engage, thereby providing additional fuel pressure and preventing engine starvation or failure during operation. This mechanism is crucial for maintaining consistent fuel flow, especially during high-demand scenarios, such as engine start-up or rapid throttle response.

The fuel pressure regulator, while important in maintaining the appropriate fuel pressure, does not directly activate the boost pump; rather, it regulates fuel pressure within the system. The engine control unit is responsible for overall engine management but does not specifically trigger the boost pump based on fuel pressure levels. The fuel flow transmitter measures the flow of fuel, but it also does not directly activate the boost pump in response to pressure changes. Thus, the 10 PSI pressure switch is the specific component designed for this task, making it the correct answer.