Subaru Coupes/Sedans/Wagons 1985-1996 Repair Guide

Vehicle Speed Sensor (VSS)

Imprimir

OPERATION



The VSS consists of a magnetic rotor which is rotated by the speedometer cable and a reed switch. Rotation of the magnet rotor pulses the reed switch OFF/ON to produce a digital signal. The signal is used as a vehicle speed coefficient in ECU calculation.

The Impreza has 2 Vehicle Speed Sensors (VSS): VSS1 is located on the right side of the transaxle case housing; VSS2 is located in the combination meter assembly.

The Legacy has 2 Vehicle Speed Sensors (VSS): VSS1 is located inside of the transaxle; VSS2 is located in the combination meter assembly.

The SVX has 2 Vehicle Speed Sensors (VSS): VSS1 is located on the right side of the transaxle case; VSS2 is located on the right side of the torque converter case. The VSS1 detects rear wheel speed and the VSS2 detects front wheel speed.

TESTING



Justy and Loyale
  1. Switch the ignition ON and check the voltage on VSS terminal 29 of the ECU.
  2.  
  3. The voltage should vary above and below 2 volts with the vehicle moving slowly.

    If the voltage varies above and below 2 volts, the VSS is functioning.
     
    If there is no response, check for VSS signal at the rear of the instrument panel. If no VSS signal is present, replace the VSS. If VSS signal is present at the instrument panel, repair the harness.
     

  4.  

Impreza
VSS1
  1. Disconnect the electrical harness from the transaxle.
  2.  
  3. Connect an ohmmeter across the transaxle's electrical harness terminals 9 and 16.
  4.  
  5. The resistance should be 450-650 ohms.
  6.  
  7. After testing, reconnect the electrical harness.
  8.  

VSS2
  1. Remove the instrument cluster from the instrument panel.
  2.  
  3. Disconnect the electrical harnesses and the speedometer cable from the instrument cluster.
  4.  
  5. Connect an ohmmeter or continuity tester across the combination meter terminals 8 and 15.
  6.  
  7. Insert a small screwdriver in the speedometer cable drive socket.
  8.  
  9. Rotate the speedometer drive and note the continuity across the VSS terminal. Continuity should turn ON/OFF 4 times per speedometer drive revolution.
  10.  

Legacy
VSS1
  1. Disconnect the electrical harness from the transaxle.
  2.  
  3. Connect an ohmmeter across the transaxle's electrical harness terminals 9 and 16.
  4.  
  5. The resistance should be 450-650 ohms.
  6.  
  7. After testing, reconnect the electrical harness.
  8.  

VSS2
  1. Remove the instrument cluster from the inst