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