Automatic Protection Switching (APS) and error signal processing coordination apparatus and methods are disclosed. If a communication module that enables communication signals and error signals to be exchanged with a remote communication module is configured in an APS protection group, error signal processing by the communication module is restricted. This prevents Time Division Multiplexing (TDM) T1/E1 Remote Defect Indication (RDI) signal processing, for example, from interfering with Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) unidirectional One-plus-One APS. Under certain conditions, however, a restricted communication module may be allowed to perform a restricted error processing operation or revert to normal unrestricted error signal processing.