Modern automobiles use onboard computers keep track of how individual parts of an engine are performing, storing this data as error codes when problems are found. The service engine soon light will come on when the computer determines that maintenance or service is required. If it does not turn off after servicing or repair, it may need to be reset to clear the error code.
Determine what type of system your car uses so you can use the proper scanning tool to clear the code, and purchase or borrow the correct scanning tool. Cars made before 1996 use the OBD system and after 1996 use the OBD-2 system.
Locate the scanning tool interface by checking under the left side of the dashboard, under the drivers seat, and under the hood in the engine compartment fuse box for the rectangular shaped connector. Refer to the owners manual if you cannot locate the interface visually.
Connect the scanning tool to the interface and switch it on.
Write down any codes it displays for future reference and use the clear or erase function on the scanner to remove them.
Select from the scanning tools menu "check engine light," select clear or erase and exit.
Disconnect the scanning tool and start the vehicle to verify the light is now off.
