Final answer:
True, the check engine light can come on if the fuel pressure in a vehicle is insufficient. This is monitored by the vehicle's electronic control unit, which triggers the light when fuel pressure issues are detected, not to be confused with the dimming of lights due to electrical loads.
Step-by-step explanation:
The question pertains to whether a vehicle's check engine light will come on if the fuel pressure is insufficient. This is indeed true. Modern vehicles are equipped with an electronic control unit (ECU) that monitors various operational parameters of the engine, including fuel pressure. When the fuel pressure falls below a preset threshold, the ECU registers an anomaly because proper fuel pressure is critical for the engine's performance and efficiency.
Insufficient fuel pressure can be due to a variety of issues such as a failing fuel pump, clogged fuel filter, or problems with the fuel injectors. When such an issue is detected, the ECU will trigger the check engine light as a warning to the driver that there is a problem with the engine's operation or its peripherals.
The behavior of lights dimming, such as when a refrigerator's motor comes on or a car's interior light dims during engine start-up, is related to electrical load and resistance rather than to the check engine light. This dimming effect is a separate phenomenon caused by a temporary drop in available electrical power as the systems demand more current. It is not directly related to fuel pressure issues.