Diagnostic Trouble Code (DTC) Information ECM-250B

Condition 

Fig 1: Front Heated Oxygen Sensor

Courtesy of VOLVO CARS CORPORATION

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that there has been no control of the heater element for the front heated oxygen sensor (HO2S) (bank 2) for a certain amount of time.

Substitute Value 

• None.

Possible Source 

• Contact resistance and oxidation in the terminals
• Damaged front heated oxygen sensor (HO2S).

Fault symptom[s] 

• Malfunction indicator lamp (MIL) lit.