Home >> BMW >> 2014 >> 650i 2D Convertible >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Self Diagnosis - Diagnostic Trouble Codes - Bank 1 (N63TU) >> Fault Code Tests >> DTC P2254: BMW DTC 12BD61; DME -- O2 Sensor Negative Current Control Circuit/Open (Bank 2 Sensor 1) >> Fault effect and breakdown warning