first off make sure you check the code and fix whatever the problem is.. after that then by resetting ecu, just unhook the neg battery for 10sec.. den it should be gone... BUT FIRST CHECK AND SEE IF ITS THROWING ANY CODE AND FIXX THE PROBLEM!!!!
More than likely it came on cus there is a problem. But, one time mine came on and I cleared it by taking off the negative cable for like 20 seconds and it came off and never came back on. I forgot to mention that I tightened the gas cap before I took off the battery cable. If your gas cap is not on properly that can cause your cel to come on.