Home >> Volvo >> 2004 >> S80 Base, 2.5 59, FWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control Module (ECM) Diagnostic Trouble Codes - 3 Of 11 >> ECM-255D: Front Heated Oxygen Sensor (Ho2S), Bank 2. Signal Too Low (B6294S2; B6294T; 2005-2006) >> Internal fault