Home >> BMW >> 2009 >> M3 2D Convertible, Automatic DCT >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Self Diagnosis - Diagnostic Trouble Codes - DTC P1602 - DTC U1153 (S65) >> MSS60 Engine Operating System DTCS >> DTC U0137, BMW Hex Code 0xCDB0, BMW Code 52656: Lost Communication With Trailer Brake Control Module (SIG) >> System test