## DTC Troubleshooting: P0500 (17-1)

DTC P0500 (17-1): | VSS Circuit Malfunction

1. | Test-drive the vehicle.

2. | Check the vehicle speed with the scan tool. Is the correct speed indicated? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the VSS and at the ECM.n NO - Go to 3.

3. | Turn the ignition switch OFF.

4. | Block the rear wheels and set the parking brake.

5. | Raise the front of the vehicle, and make sure it is securely supported.

6. | Turn the ignition switch ON (II).

7. | Block the right front wheel, and slowly rotate the left front wheel.

8. | Measure voltage between ECM connector terminals A18 and A24. Does the voltage pulse between 0 V and 5 V or battery voltage? YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.n NO - Go to 9.

9. | Turn the ignition switch OFF.

10. | Disconnect ECM connector A (31P).

11. | Turn the ignition switch ON (II).

12. | Block the right front wheel, and slowly rotate the left front wheel.

13. | Measure voltage between ECM connector terminals A18 and A24. Does the voltage pulse between 0 V and 5 V or battery voltage? YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.n NO - Check these items: A short or an open in the wire between the ECM (A18) and the VSS. If the wire is OK, test the VSS.n