Vehicle Speed Signal Circuit Troubleshooting

Special Tools Required:  Test Harness 07LAJ-PT3020A

1. Disconnect the 3P connector from the VSS (vehicle speed sensor) (A).
   Fig 1: Disconnecting 3-Pin Connector From VSS

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
2. Connect the test harness only to the engine wire harness.
3. Connect the RED test harness clip (B) to the positive probe of an ohmmeter. Cover the white (C) and green (D) test harness with protective tape (E).
4. Check for continuity between the RED test harness clip and body ground.
   1. Is there continuity? 
      1. YES:  Go to step 5.
      2. NO:  Repair open in the BLK wire between the VSS and G101.
5. Connect the WHT test harness clip (C) to the positive probe of a voltmeter, and connect the RED test harness clip (B) to the negative probe.
   Fig 2: Connecting WHT Test Harness Clip To Positive Probe Of A Voltmeter & Connecting RED Test Harness Clip To Negative Probe

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
6. Turn the ignition switch ON (II).
   1. Is there battery voltage? 
      1. YES:  Go to step 7.
      2. NO:  Repair open in the BLK/YEL wire between the VSS and the under-dash fuse/relay box.
7. Disconnect the WHT test harness clip (C).
8. Connect the GRN test harness clip (D) to the positive probe of a voltmeter.
   1. Is there 5 V or more? 
      1. YES:  Go to step 9.
      2. NO:  Repair short in the BLU/WHT wire between the VSS and the ECM.
   Fig 3: Connecting GRN Test Harness Clip To Positive Probe Of A Voltmeter
   Courtesy of AMERICAN HONDA MOTOR CO., INC.
9. Turn the ignition switch OFF.
10. Connect the other test harness connector (A) to the VSS (B).
    Fig 4: Connecting Other Test Harness Connector To VSS

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
11. Raise the front of the vehicle, and make sure it is securely supported.
12. Put the vehicle in neutral with the ignition switch ON (II).
13. Slowly rotate one wheel with the other wheel blocked.
    1. Does voltage pulse from 0 to approx. 5 V or more? 
       1. YES:  Go to step 14.
       2. NO:  Replace the VSS.
14. Disconnect the 30P connector "A" from the gauge assembly.
15. Connect a voltmeter between the BLU/WHT wire and body ground.
    Fig 5: Connecting A Voltmeter Between BLU/WHT Wire & Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
16. Slowly rotate one wheel with the other wheel blocked.
    1. Does the meter indicate pulsing voltage? 
       1. YES:  Replace the speedometer.
       2. NO:  Repair open in the BLU/WHT wire between the VSS and the speedometer.