2010 GMC Terrain 2.4.  ECU / ECM was replaced, security lamp is off  (P00633 is stored) and cannot perform the security key relearn process.  The only other code is P0315 for. Crankshaft position which will not reset until the engine starts.   If I reinstall the original ECU / ECM the engine will start and run but the stalling and over fuel conditions return.  In my opinion, if the BCM, key or immobilizer module were bad the vehicle would not start with the original ECU / ECM installed.