A computer that determines air/ fuel ratios by using a multitude of sensor that relay existing conditions both on the outside side and inside of a vehicle. Then places this data into a pre programed 3D fuel map. Modern ECU’s also handle other functions of a vehicle such as traction control and ABS; though they may be a separated unit from the fuel control or Engine management ECU’s
The exhaust valve is the valve through which the burnt exhaust gases escape the cylinder into the exhaust manifold. They are generally mechanically actuated by the camshaft and rocker arm assembly but in newer camless engines can be actuated by electronic and hydraulic control.
The engine temperature gauge informs you of the operating temperature of the vehicle. Usually when the vehicle starts it will be on the cold side and slowly move towards the center. Once the vehicle is at normal operating temperature it should stay around the center. If you car is consistently running hot towards the top of the gauge you should have your engine inspected to prevent overheating and costly repairs. Some vehicles have digital temperature gauges that will give you the actual temperature of the vehicle. You should consult your owners manual for the normal operating temperature of your vehicle.
Engine Service refers to the periodic maintenance that is required to be performed on the engine in order to keep it running smoothly for a long time. A basic service would require oil change, oil and air filter change and coolant renewal.