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.
mance of a vehicle plus store the associated fault code and condition in memory. If a problem is detected and then re-detected during a later drive cycle more than one. time, the OBD II system must also illuminate the Check Engine Light in the instrument. cluster to alert the driver that a malfunction has occurred. However, the flash code func-. tion of the Check Engine Light in OBD I vehicles is not a function in OBD II vehicles.