On older cars, the check engine light can be reset by disconnecting the negative battery terminal for 20 to 30 seconds. Take newer cars to an auto shop to have the check engine light reset with tips from a certified master mechanic in this free video on car maintenance.
Good afternoon my name is Tom Brintzenhofe and I am a Certified Master Mechanic out of Reading, Pennsylvania and today we are going to talk a little bit about how to turn off a check engine light and reset a check engine light. Now everything up to the mid-90's, 94 or 95 and maybe even some in the mid 96's you can get away with the first technique I am going to show you and that is disconnecting your negative battery terminal. This isn't too bad but what you will want to do is loosen your battery terminal up and sometimes you get a little screwdriver in here and pry it open a little bit and turn your battery terminal off for about 15 to 20 seconds and if you want you can count it out and just wait a little bit. Sometimes depending on some of the older vehicles sometimes you have to wait 30 seconds. Then just put your battery terminal back on and turn your terminal back on and make sure it is nice and snug here and you want to start your vehicle back up and check and see if your light is off. If your light isn't off it has probably got the newer OBD2 systems in it. If it has an enhanced OBD2 system in it you will need a scanner similar to this one here, they make different brands out there. This is one of them that I choose to use that is a lot simpler design to use, it is more user friendly. Unfortunately you don't want to buy these yourself because they cost a couple thousand dollars but this one here with a little bit of training, get in there and reset your check engine light. It would be easier to do it yourself or at home to stop by your local shop and it is usually about $60 to have them reset it for you. It sure beats trying to buy one of these things but if the first technique doesn't work for you disconnect your negative battery terminal for about 20 to 30 seconds and if that doesn't work for you you are going to have to take it to a local shop and have them do it there but that is about what you need to do to reset a check engine light.