Checking the vehicle speed sensor (VSS) signal

Fig 1: Engine Start Verification

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off.
• Remedy the transmission control module (TCM) and vehicle speed sensor (VSS) connectors for contact resistance and oxidation according to Contact resistance and oxidation .
• Raise the car so that the drive wheels are clear of the ground.
• Start the engine and let it idle.
• Shift the gear selector to position D so that the drive wheels begin to rotate.
• Read off the transmission speed.

  Depress the accelerator pedal (AP) and check that the speed is updated.

  NOTE:

  Ensure that the wheels are not rotating when the gear selector is moved.

  NOTE:

  Diagnostic trouble codes (DTCs) may be stored in the ABS system when the rear wheels are stationary and the front wheels rotate. Erase any diagnostic trouble codes (DTCs) stored in the ABS system after fault-tracing.

  If speed is updated, the cause of the fault was probably contact resistance or oxidation in the control module or vehicle speed sensor (VSS) connectors.

  Fig 2: Identifying VCT2000

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Was the speed updated? 

• YES 

  FAULT NOT FOUND:  Troubleshooting has been completed.

• NO 

  Refer to Checking wiring and sensors