Abstract: A processor of a cellular modem monitors for the presence of a residual echo signal during a full-duplex portion of a training sequence. In particular, the processor monitors an equalizer error signal during a full-duplex training phase that follows the half-duplex training phase for the echo canceler. If the processor detects a level of the error signal greater than a predefined threshold, the processor presumes the increase in the error signal is due to the presence of a residual echo signal and performs a predefined adjustment of the taps of the corresponding echo canceler of the cellular modem.