How do you reset the check engine light on a 2004 Nissan Frontier?

To reset the check engine light on a 2004 Nissan Frontier, you can disconnect the battery by removing the negative terminal for about 15 minutes. This will clear the engine control unit's memory, including the check engine light. Alternatively, if the underlying issue has been resolved, you can use an OBD-II scanner to erase the trouble codes that trigger the light. Always ensure that the root cause of the check engine light is addressed before resetting it.