Conditions For Clearing MIL/DTC

The control module turns OFF the Malfunction Indicator Light (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.