Check Engine Light in Austin, TX
A modern vehicle has more on-board computing power than the Apollo spacecraft that went to the moon!
The application of computer controlled fuel and emission systems has increased our fuel mileage, horsepower per liter and cleaned up our air. It is truly an improvement over the carburetor of yesterday.
The 1970 fully equipped Cadillac weighed 4409 lbs. It had a 7.7L engine with 288 horse power and got an average of about 10mpg.
The 2012 Cadillac weighs 3900lbs and has a 3.6L engine delivering 318 horsepower and 22mpg!
The computer in modern cars controls the a/c system, windows, fuel, emissions, transmission, brakes, navigation and many other systems. Eventually, cars will drive themselves enabling the driver to watch TV or surf the net while going to work.
The computer system for fuel delivery is basically comprised of the main computer called the Electronic Control Module or ECM and various sensors. The ECM is fed information from various sensors located in the engine and exhaust systems.
The sensors related to fuel delivery monitor data from the engine, such as the position of the throttle, the amount of air coming in the engine, the hydrocarbons of the exhaust, the coolant temperature, the position of the crankshaft and camshaft, the outside air temperature and many others. The sensors feed the data back to the ECM and the computer measures the proper amount of fuel needed at that time.
Check Engine Light
The check engine light is the warning light for the system. It is an orange light that usually displays “check engine” or “service engine soon”. When the light is on, it lets you know the computer has detected a malfunction with a sensor in the system.
When diagnosing a malfunction in the system, it is important to remember the codes provided by the computer do not “tell you what’s wrong” with the system. The code tells the diagnostician what the condition is. For instance, the code may indicate a “lean burn” condition. This can be caused by many different things and the components must be checked individually.
One condition that we often see is easily corrected by the vehicle owner and that’s the gas cap. A loose gas cap will set the check engine light. It should be the first thing checked. If the cap is loose, tighten it and drive the car a few days. If the light doesn’t go off, it may need to be reset by a professional.
Specialized testing equipment is needed to properly diagnose the system, and as cars become more sophisticated, so does the technical training and equipment.
The other computer control systems have their own modules and sensors. These modules and sensors replace a whole host of heavier parts like actuators, vacuum pots, vacuum accumulators, vacuum hoses and so on. This has resulted in lighter, more fuel efficient cars and trucks.