Checking connector

Fig 1: Identifying Ignition Switch OFF Position

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off.

  Check front heated oxygen sensor (HO2S) connector for contact resistance and oxidation according to Contact resistance and oxidation .

  CAUTION:

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

  Remedy as necessary.

  Other information 

  • To access/replace the heated oxygen sensor (HO2S), see Heated oxygen sensor (HO2S), replacing
  • For information about signals, see Signal specification
  Fig 2: Identifying 4-Bit connector

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  Fig 3: Identifying Ohmmeter

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• Continue 

  Refer to Checking connector 

Fig 1: Engine Start Verification

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Fig 2: Identifying Connector(s) Reinstallation

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off.
• Reinstall components, reconnect connectors etc.
• Start the engine and let it idle.
• Read off the lambda value for the rear heated oxygen sensor (HO2S).
  NOTE:

  It takes approximately 25 seconds before fuel trim starts.

  Check that the value is within its permitted range. The value should be approximately 0.98 and 1.02.

  If the value is now OK it means that the cause of the fault has been loose connections in connector.

  Other information 

  • To access/replace the heated oxygen sensor (HO2S), see Heated oxygen sensor (HO2S), replacing
  • For information about signals, see Signal specification .
  Fig 3: Identifying VCT2000 Diagnostic Tool

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Is the value OK? 

• YES 

  OKAY:  Troubleshooting has been completed.

• NO 

  Refer to Checking wiring and components