To disable the service engine light in a vehicle, use a scan tool, or disconnect the car's battery. It is easier and safer to use a scan tool, though without one, the process generally takes 20 to 30 minutes.
- Disable the battery connection
Follow the manufacturer's directions if using a scan tool. A scan tool typically requires a connection to the vehicle's on-board diagnostics data link connector. If a scan tool is not being used, disconnect the positive battery cable from the battery terminal.
- Allow the emissions and trouble code data to reset
Briefly turn the ignition switch on and off three times while the battery is disconnected. Leave the battery disconnected for 5 to 10 minutes.
- Reconnect the car battery
Carefully reconnect the positive cable to the battery terminal. Be sure the vehicle's ignition is turned off during this step as there is a risk of electrical damage to the emission components.
- Start the vehicle
Turn the vehicle's ignition on, and wait a full minute before starting the vehicle. Upon starting the car, the check engine light should be turned off. If using a scan tool, ensure that it is disconnected from the data link connector before starting the vehicle.