The vapor pressure of a liquid is the point at which equilibrium pressure is reached, in a closed container, between molecules leaving the liquid and going into the gaseous phase and molecules leaving the gaseous phase and entering the liquid phase.n explanation of vapor pressure. Vapor pressure is constant when there is an equilibrium of water molecules moving between the liquid phase and the gaseous phase, in a closed container.
When a potential problem is detected, a dashboard warning light called a malfunction indicator light (MIL) is illuminated to alert the driver. An OBD system detects a problem well before symptoms such as poor performance, high emissions or poor fuel economy are recognized by the driver.
Edit Answer (for another -35 minute). The light being on indicates a fault code stored in memory. This could have occurred during the oil change, if a wire or line got knocked off. The code is retrieved and used to diagnose the fault that caused it.Once the fault is corrected, the code is cleared and the light will be out.Here is more information on check engine lights.his could have occurred during the oil change, if a wire or line got knocked off. The code is retrieved and used to diagnose the fault that caused it. Once the fault is corrected, the code is cleared and the light will be out. Here is more information on check engine lights.