Checking the control unit and wheel sensor connectors

Fig 1: Identifying Ignition ON

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Connecting Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off.
• Check the connector of the ABS control unit and the wheel sensor for contact resistance and oxidation, as described in Contact resistance and oxidation .
• Connect the connectors, install the components, etc.
• Raise the car so that the relevant wheel hangs free.
• Ignition on.
• Read off the speed of the relevant wheel.

  Spin the relevant wheel and check whether wheel speed has been updated.

  If the wheel speed is updated, the fault has been caused by a poor contact in the connector of the control unit or wheel sensor.

  Additional information: 

  • For disconnection of the wheel sensor connector see Wheel sensor, front, replacing .
  • For disconnection of the ABS control unit connector see Replacing the control module for ABS and dynamic stability and traction control (DSTC) .
  Fig 3: Identifying VCT2000 Diagnostic Tool Symbol In VIDA

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Is wheel speed updated? 

• YES 

  OKAY:  Troubleshooting has been completed.

• NO 

  Refer to Checking the wiring and sensor