How do you get the check engine light in your car to go off?

The ECM has self-diagnostic capability and constantly tests operation of sensors and other components. When any of the sensor signals is missing or out of normal range, the ECM sets a fault and illuminates the "Check Engine" or "Service Engine Soon" light also called MIL (Malfunction Indication Light) storing the corresponding Diagnostic Trouble Code (DTC) in the ECM memory. The same will happen if a mechanical component of controlled system fails. For example, if the EGR valve fails, this will also cause the "check engine" light to come on. Even a loose gas cap will cause the "check engine" to come on.The stored trouble code can be retrieved with the special scan tool by the technician. The code itself does not tell exactly which part to replace, it only gives a direction where to look for - the technician has to perform certain tests specific for each code to find the exact cause of the problem. Once the problem is corrected the check engine light can be turned off by the technician. If you reset the light and do not repair the problem the light will just come back on.

AnswerYou can buy a scantool at Walmart and turn the "check engine" light off yourself. Presuming that you repaired the malfunctioning part/s. I had my check engine light on for some time and I was very reluctant to take it to the mechanics. I decided to by an OBD 2 scantool from Walmart ($70) and used it to troubleshoot my 2000 Explorer XLT before sending it to the town mechanics(God knows that they will give you all types of BS). Anyway, it gave me a code, I looked it up with the book that came with it and found it was something wrong with my vacuum pressure. I then bought a Chiltons book and found out what causes the problem. All I had to do was check for a loose air hose connection or joint. Im not a mechanic but I found all the hoses(that mattered) and one of them was just a little bit loose. I tightened it, plugged the OBD2 scantool back in, erased the check engine light and it hasn't come back since. If I didnt fix it before I erased it, the light would have come back on after a little while of driving it. Oh, and since I had no use for the scantool anymore, I returned it to Walmart the next week for a full refund! AnswerAll I usually do is unhook the battery for 5 or 10 minutes and the light will go off. If there's really no problem, it should stay off. Otherwise, you should go to a place like AutoZone to see what code(s) it's throwing (for free). When we get ours emissions tested, they won't do it with the 'check engine' light on, so we have to unhook the battery before we leave home. The light usually stays off long enough to get it tested, and it has passed each time we got it tested.