Disconnecting your battery cable for a couple minutes will erase compuer memory and make the light go out, as long as there is not some hard fault existing in the vehicle to make the light turn back on again right away.
You should be aware that this will also erase all clues to the cause of the problem from computer memory, so by doing this you are eliminating any information the technician can use to locate the source of the problem if you do decide to have the problem diagnosed and repaired. The light does not come on for no reason; the computer saw something wrong when the light was turned on, even if the truck appeared to be running normally at the time. It may be an emissions related failure, but I would recommend having the vehicle checked so that you know for sure....
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