Vehicle Speed Signal Circuit Troubleshooting

Vehicle Speed Signal Circuit Troubleshooting

Note: If the MIL indicator is ON, troubleshoot the PGM-FI problem first.

1. Raise the vehicle with the transmission in neutral and make sure it is securely supported.
2. Disconnect the VSS 3P connector.




3. Turn the ignition switch ON (II).




4. Check for continuity between the VSS 3P connector No. 3 terminal and body ground.

Is there continuity?

YES - Go to step 5.

NO - Repair open or high resistance in the BRN/YEL wire between the VSS and G101.




5. Measure voltage between the VSS 3P connector No. 1 terminal and body ground.

Is there approx. 5 V?

YES - Go to step 6.

NO - Repair short or open in the YEL/BLU wire between the VSS and the ECM.

6. Reconnect the VSS 3P connector.
7. Slowly rotate the propeller shaft.




8. Measure voltage between the gauge assembly connector C (20P) No. 3 terminal and body ground ('00-03 models) or between the gauge assembly connector B (30P) No. 7 terminal and body ground ('04-05 models).

Does voltage pulse from 0 to about 5 V?

YES - Check connections, and if necessary, replace the printed circuit board.

NO - Go to step 9.

9. Turn the ignition switch OFF.
10. Disconnect the 3P connector from the vehicle speed sensor (VSS).
11. Turn the ignition switch ON (II).
12. Measure the voltage between the VSS 3P connector No. 2 terminal and body ground.

Is there about 5 V?

YES - Replace the VSS.

NO - Repair the short to ground or open in the BLU/WHT wire.