The sub-iterations for an equation end when the ratio of the residuals at the current sub-iteration and the first sub-iteration is less than the value specified in the Correction Tolerance field. You can monitor the details of the sub-iteration convergence by looking at the AMG solver performance (that is, setting the Verbosity field in the Multigrid tab in the Advanced Solution Controls dialog box to 1). Be sure to pay attention to the residuals for the current sub-iteration (that is, the residual for the 0-th AMG cycle at the current sub-iteration) and the initial residual of the time step (that is, the residual for the 0-th AMG cycle of the first sub-iteration). The ratio of these two residuals is what is controlled by the Correction Tolerance field. These two residuals are also the residuals plotted when using the Residual Monitor panel and reported in the ANSYS FLUENT console at the end of a time step. Note that the residuals reported at the end of a time step can be scaled or unscaled, depending on the settings in the Residual Monitor dialog box. The residuals reported when monitoring the AMG solver performance are always unscaled