MAP Sensor
If you are an American, chances are you live in a suburb. And if you live in a suburb, chances aren’t good that you have access to viable public transportation that will get you everywhere you need to go. For that reason, you probably rely on your car for quite a bit of your transportation needs (to get back and forth to work, haul groceries, haul your child’s soccer team, etc.) And if that is the case, you will surely be inconvenienced if a problem occurs with your car, truck, van, scooter or other vehicle. If a problem does occur, and problems are inevitable in this life, then you will probably take your vehicle to a mechanic or to one of your dealership’s automotive technicians in order to get it fixed. Sometimes the terms mechanics or technicians throw around can sound like gobbledygook, but you should pay attention. One of the things that could go wrong with your auto is its auto MAP sensor.
If your mechanic explains to you that there is some sort of problem with your auto MAP sensor, what he is trying to tell you is that there is a problem with a sensor on your car that is used to measure manifold absolute pressure. Manifold absolute pressure (also called MAP, and the reason it’s called a “auto MAP sensor”) is monitored by the auto MAP sensor. This device measures the difference between the pressure in your auto’s intake manifold and the pressure in the outside atmosphere.
Now why is measuring the difference between the pressure in your auto’s intake manifold and the pressure in the outside atmosphere so important? This information is important because readings taken from the auto MAP sensor are then used by your engine’s computer to monitor engine load. The auto MAP sensor tells your car’s computer when the engine is under pressure. This report, in turn, sets off a chain of events that allows your car to run more smoothly. When this chain of events is not set off (i.e. when there is a problem with your auto MAP sensor) then the car’s computer does not receive this reading and does not run at optimal performance. This lack can cause your car to quickly begin malfunctioning in other ways and eventually lead to a major break down that could include costly repairs. See? That’s why the auto MAP sensor, an auto part you may never even have conceived of as existing, is important to you and to your car or trucks’ well being.
The auto MAP sensor is just one of many sensors used within an internal combustion engine's electronic control system. Now, if you know a little about cars, it will make sense to you to know that most engines that use a MAP sensor are fuel injected and that the auto MAP sensor is so smart that it is able to provide pertinent information to your engine’s computer almost instantaneously.
So what exactly do auto MAP sensors tell your engine? Well, auto MAP sensors tell your engine its own air mass flow rate. In turn, the engine, now duly informed, calculates the appropriate flow of fuel to keep your car running at its peak performance. This is all calculated using a method called the speed-density method. Two other necessary parts of the speed-density equation (yes, it really is an equation) are engine speed (i.e. revolutions per minute or RPM) and air temperature. Only with all of these elements present can your auto MAP sensor sense the difference in pressure from within and outside your manifold, pipe that information quickly to your engine’s computer, and ensure that your car runs and optimal performance, leaving you with plenty of time to get to that soccer game.
