Home >> BMW >> 2013 >> 335i 2D Convertible, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Self Diagnosis - N55 - Diagnostic Trouble Codes - DTC P0478 (BMW DTC 138101) Through DTC P0440 (BMW DTC 191D01) >> DTC P0327; BMW DTC 168A71: Knock sensor, signal: electrical fault KS (loose contact) or KS loose >> Action in service