Checking the heated oxygen sensor (HO2S)

Fig 1: Identifying Ignition OFF

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Disconnecting Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off
• Disconnect the connectors for the front (ECM-18) and rear (ECM-1C) heated oxygen sensor (HO2S).

  Check the connectors for contact resistance and oxidation according to Contact resistance and oxidation .

  Remedy as necessary.

  Fig 3: Identifying Ohmmeter

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Was a fault detected? 

• YES 

  Refer to Verification 

• NO 

  Refer to Checking the power cable