the light can even come on for a gas cap loose .
Autozone , and Shucks will pull the code for free . (find the conn. first ,helps)
or
you can rent a code reader from them for cheap
or
you can buy one here for cheap
Harbor Freight Tools - Quality Tools at the Lowest Prices
or pay dealer $125 .
when it comes on , you can do many things.
but getting the code can save trouble later, and costs.
At the min. every family should all pitch in $5 and have a jointly owned reader.
make sure it can read CAN buss , and then its furture is guaranteed.
many folks do this.
or ask a friend, do you have an obd2 reader.
Pull the codes (DTC;s) from your ECU.
Then we have something to work with.
cheers.