1. Turn off the engine and allow it to cool down.
2. Open the hood and locate the battery. The battery is located on the passenger side of the engine compartment, near the firewall.
3. Disconnect the negative battery terminal from the battery. Use a wrench to loosen the nut that holds the negative battery terminal cable to the battery. Be careful not to drop the nut into the engine compartment.
4. Wait for at least 10 minutes. This will allow the vehicle's electrical system to reset.
5. Reconnect the negative battery terminal to the battery. Tighten the nut until it is snug.
6. Start the engine and allow it to run for a few minutes. The check engine light should now be off.
If the check engine light is still on after you have followed these steps, you will need to take your vehicle to a qualified mechanic for further diagnosis.
Here are some additional tips for resetting the check engine light on a 2004 Ford F-150:
* If you do not have a wrench, you can use a pair of pliers to loosen the nut that holds the negative battery terminal cable to the battery.
* Be careful not to touch the positive battery terminal with your wrench or pliers. This could cause a short circuit and damage your vehicle's electrical system.
* If you are uncomfortable working on your own vehicle, you can take it to a qualified mechanic for assistance.
