Disconnect the battery. Open the hood of the car and locate the battery. It is usually located in the engine bay, on the driver's side. Use a wrench to loosen the negative battery terminal (marked with a "-") and disconnect it.
Wait 10 minutes. This will allow the car's computer to fully reset.
Reconnect the battery. Reconnect the negative battery terminal to the battery.
Start the car. Turn the key in the ignition and start the car. The check engine light should be off.
If the check engine light is still on, you may need to have the car scanned for codes. This will tell you what is causing the light to come on, and you can then take steps to fix the problem.
Here are some additional tips that may help you to reset the check engine light on a 1999 Chevy Cavalier:
Make sure that the car is in "Park" or "Neutral" gear.
Turn the key in the ignition to the "On" position, but do not start the car.
Press the gas pedal all the way down and release it five times.
Turn the key in the ignition to the "Off" position.
Wait 10 seconds.
Start the car. The check engine light should be off.
These steps may not work on all 1999 Chevy Cavaliers. If you are unable to reset the check engine light, you may need to have the car scanned for codes.
