Cars and Computers

CARS AND COMPUTERS

Taylor Williams

CIS 116

Kathy Carrillo

14 November 2015

Taylor Williams

Kathy Carrillo

Computer Essentials

14 November 2015

Cars and Computers

        Stick the key in the ignition. Twist the key to start the vehicle. When the key turns in the ignition, the expected outcome is the vehicle to start up. People rely every morning on their vehicle to start up, drive, and transport them safely to their destination. While every brand has their own way of setting up a vehicle, they all have the basic structures; a body, tires, steering wheel, are some of the basic recognizable features on a car. From the American muscle cars to the European sports car, they all have something in common: vehicle computers and sensors.

        From the moment the engine has been started, the coolant temperature, engine oil pressure, transmission status, and fuel level are all diagnosed by engine sensors, and their status is reported to the driver of the vehicle. Sometimes the vehicle alerts the driver by using analog gauges. Some vehicles only alert the driver only when there is something wrong by showing a “Check Engine” light on the dashboard to tell the driver that the vehicle is in need of maintenance (Understanding Your Vehicles Sensors).

        Controlling the engine in a vehicle is one of the more processor-intensive jobs that a vehicle does. The Engine Control Unit or ECU is the most powerful computer in vehicles. The job of the ECU is to monitor the output of a system to control the inputs of a system in a process called closed-loop control.This process helps manage emissions and fuel economy of the vehicle’s engine. The ECU  gathers information from different sensors throughout the vehicle and is capable of knowing everything from the[pic 1] temperature of the coolant to the amount of oxygen in the exhaust. Once the Engine Control Unit performs thousands of calculations in order to determine how long the fuel injector should be open and when the next spark timing should be. The ECU does all this to ensure the vehicle is receiving the best gas milage and the lowest emissions (How Stuff Works: Auto 1). [pic 2]

        Every vehicle comes with dozens of different sensors and computers. Each device has a purpose that helps the vehicle run and tell it what to do. Each sensor sends a code to to the ECU which then determines the next course of action. Some vehicle sensors are oxygen sensors, knock sensors, manifold absolute sensors, and throttle position sensors— just to name a few. All these sensors in particular work together to help the vehicle run smoothly. They send and receive messages to and from the Engine Control Unit (How Stuff Works: Auto 2). Every sensor and computer requires an overwhelming amount of harnesses, connections, and electrical wires. Everything from powering the automatic windows to starting the engine requires wires and sensors.

        The Knock Sensor is a device that when stressed, voltage is produced. A knock is produced when fuel will not comply with the required amount of quality. When this happens, it created an uncontrolled combustion process which is likely to cause damage to the vehicles engine. The knock sensor prevents this from happening by sensing the knock and sending the information to the ECU. This influences the timing of the fuel injection until the knock stops (Car Sensors). [pic 3]

        The Manifold Absolute Pressure sensor or MAP sensor is used to monitor the change in pressure between the outside atmosphere and intake manifold. When the engine is working harder than normal, the intake vacuum drops. This forces the engine to suck in more air which then requires more fuel to keep the fuel to air ratio balanced. In order to produce more power when a heavier signal from the MAP sensor is received, the fuel mixture will be richer. While this happens, the ECU will slow down the ignition timing slowly in an attempt to prevent a spark knock.  [pic 4]

        Fixing a vehicle was simple and straightforward before the use of computers and sensors. Vehicles were easier to diagnose being that the systems were mechanical. All that was needed was a wrench and few tools to help finish the job. If there was gasoline in the tank, he vehicle had everything it needed to run and take the driver where he or she needed to go. Now a days, modern engines need the proper amount of air and fuel mixture in order to set off a spark for the pistons shoot downward causing the engine to run. Today, engines are controlled in a variety of specific ways to help the engines fuel economy to obtain better gas mileage and reduce emissions.  In order for this to work properly; all the sensors, computers, temperatures, engine speed, crankshafts must all be in order or the engine my not work properly or at all. For example, if the crankshaft position sensor fails, the engine will not know when the spark plugs should fire causing it not to start. If the temperature sensor stops working, the engine may sense a cold engine and send a message to the fuel injector to start releasing more gasoline, therefore, causing the engine to misfire and run poorly or not run at all. It has become difficult to work on vehicles unless the driver owns a computer to scan and diagnose the engine and receive an engine code to fix the vehicle properly. Occasionally, there is nothing wrong with the vehicle. The sensors are just off and sending the wrong codes to the ECU (Understanding Your Vehicles Sensor).