Home >> Volvo >> 2004 >> V40 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control Module (ECM) Diagnostic Trouble Codes - 1 Of 3 >> ECM-16: Front Heated Oxygen Sensor Signal. Signal Too Low. Permanent Fault (B4204T3 (Ca) (Us); 2001-2003) >> Signal too low. Permanent fault