Home >> Subaru >> 2004 >> Baja Base, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Diagnostic Trouble Code (DTC) Detecting Criteria (H4SO U5 (PZEV)) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0128: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) >> Enable Condition