The article examines the meaning of the malfunction indicator lights (MIL) on your car that indicate that the evap system pressure sensor input is low for the evaporative emission control system of the vehicle. It should be noted that this type of vehicle emission system is designed to prevent gas leakage into the atmosphere. In an effort to reduce air pollution, the United States government required all automotive vehicles to have fully sealed fuel systems. To assist in this effort, the fuel evaporation control system ensures that gasoline vapors are kept inside the carburetor reservoir and the fuel tank, causing the fumes to be trapped in the activated carbon containers. Meanwhile, an indication that the differential pressure sensor is not working as it should be is the MIL warning of the low input of the evap system pressure sensor.
Ensuring that gas smoke does not leave the fuel tank is a valuable effort to combat air pollution, because approximately 20% of a car’s hydrocarbon emissions emanate from evaporation. In addition, the storage of activated gasoline gasoline vapors saves fuel consumption. This system for regulating vehicle emissions uses engine speed, air inlet volume, oxygen sensor information, engine speed and coolant temperature to ensure that the evap system works properly.
In this emission control system, the vapor pressure transducer, which can be one of Keller’s pressure sensors, produces a voltage that is monitored by the on-board computer. When this voltage drops to a value that is below a predefined threshold, the MIL light is activated by the computer because that means that a substantial percentage of gasoline vapors have escaped. It is also possible that the pressure sensor or switch has broken. Therefore, it is appropriate for the automobile computer to activate the MIL to warn the driver.
For the driver, it is time to check the vehicle’s emission control system if the MIL lights are on and the system has issued a low warning of the evap system pressure sensor. You can perform some diagnostics, but it can often be advisable to get the services of a skilled mechanic. The leakage may be so small that it is almost impossible to locate it, because it is necessary to have a type of EVAP smoke machines to make the leak visible. If you want to check the evap emission control system, you can look for the leak by examining the various components, including a cartridge, a gas cap, a vapor and liquid separator, and the fuel tank. The on-board computer system performs a quick check that the evaporator system air path to the engine is not blocked. The computer will also use a purge flow detector to ensure there is no fuel leakage. If you suspect a substantial fuel vapor leak, you can evaluate the filler tank seal line seal. It is also important to check the bottom of the gas cap for damage, debris or scratches.