What is the status of the yellow hydraulic system when the ENG PUMP switch is on and hydraulic pressure is low?

The scenario presented indicates that the ENG PUMP switch is activated, and at the same time, there is low hydraulic pressure in the yellow hydraulic system. When the ENG PUMP switch is on, it allows the engine-driven pump to provide pressure to the hydraulic system. However, if the hydraulic pressure is still indicated as low despite the pump being active, it signifies that there is a problem in the system.

This situation could occur due to various reasons such as a leak in the hydraulic system, a failure in the pump itself, or other related issues causing insufficient hydraulic pressure. In essence, the yellow hydraulic system is being actively supplied with hydraulic fluid through the engine pump, but for some reason, it is not achieving the required pressure levels.

The other options generally describe conditions that would not be expected when the ENG PUMP switch is in the 'on' position while simultaneously having low hydraulic pressure, pointing to specific issues that are not indicated in the original question.