Checking the connector

CAUTION:

Do not apply rust solvent spray or grease to the heated oxygen sensor (HO2S) connector.

Fig 1: Engine Start Verification

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Connecting Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

Ignition off
Check the heated oxygen sensor (HO2S) connector. Check for contact resistance and oxidation
Reinstall the components, reconnect the connectors etc.
Start the engine. Allow the engine to idle.
Read off the signal for the rear heated oxygen sensor (HO2S).

NOTE:
It may take up to approximately 3 minutes before fuel trim has begun and the signal can be read off.

Check that the signal is within its permitted range. There must be no interference in the signal and it must be above 0.6 V or below 0.3 V.

If the signal is now OK this indicates that the fault was caused by a poor connection in the connector.

Other information:
- To access or replace the heated oxygen sensor (HO2S), see Heated oxygen sensor (HO2S), replacing
- For information about signals:
  - For 6 cylinder engines -2001, see Signal specification
  - For 6 cylinder engines 2002-, see Signal specification
  - For 6 cylinder engines -2004, see Signal specification
  - For 6 cylinder engines 2005-, see Signal specification .
- See Contents .
Fig 3: Identifying Rear Heated Oxygen Sensor (HO2S) Connector
Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 4: Identifying VCT2000 Diagnostic Tool Symbol In VIDA
Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 5: Identifying Rear Heated Oxygen Sensor (HO2S)
Courtesy of VOLVO CARS OF NORTH AMERICA.

Is the signal OK?