WEBVTT - What does the computer in a car do? 0:00:00.560 --> 0:00:03.840 Welcome to brain Stuff from how stuffworks dot com where 0:00:03.880 --> 0:00:08.520 smart Happens. I am Marshall Brain with today's question, what 0:00:08.680 --> 0:00:13.400 does the computer in a car do? All cars manufactured 0:00:13.400 --> 0:00:16.800 today contain at least one computer. It's in charge of 0:00:16.840 --> 0:00:20.480 monitoring engine emissions and adjusting the engine to keep emissions 0:00:20.520 --> 0:00:24.480 as low as possible. The computer receives information from many 0:00:24.600 --> 0:00:29.440 different sensors, including the oxygen sensor, the air pressure sensor, 0:00:29.640 --> 0:00:34.000 the air temperature sensor, the engine temperature sensor, the throttle 0:00:34.080 --> 0:00:38.120 position sensor, the knock sensor, and so on. Using the 0:00:38.200 --> 0:00:42.320 information from these sensors, the computer can control things like 0:00:42.360 --> 0:00:45.560 the fuel injectors, the spark plugs, and the idle speed 0:00:45.840 --> 0:00:49.280 to get the best performance possible from the engine while 0:00:49.400 --> 0:00:53.480 keeping emissions low. The computer can also sense when something 0:00:53.560 --> 0:00:56.200 has gone wrong, and it can inform the driver with 0:00:56.280 --> 0:01:00.000 the check engine light. A mechanic can read a diagnostic 0:01:00.160 --> 0:01:03.120 code from the computer and fix the problem. Do you 0:01:03.120 --> 0:01:06.560 have any ideas or suggestions for this podcast? If so, 0:01:06.680 --> 0:01:09.399 please send me an email at podcast at how stuff 0:01:09.400 --> 0:01:12.160 works dot com. For more on this and thousands of 0:01:12.160 --> 0:01:16.760 other topics, go to how stuff works dot com.