DTC Troubleshooting: P0500 (17-1), P0501 (17-2)

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/PCM connector terminals A18 and A24.

 

Does the voltage pulse between 0 V and 5 V or battery voltage?


YES - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original  ECM/ PCM.n


NO - Go to 9.

9.Turn the ignition switch OFF.

10.Disconnect the negative cable from the battery.

11.Disconnect ECM/PCM connector A (31P).

12.Reconnect the negative cable to the battery.

13.Turn the ignition switch ON (II).

14.Block the right front wheel, and slowly rotate the left front wheel.

15.Measure voltage between ECM/PCM connector terminals A18 and A24.

 

Does the voltage pulse between 0 V and 5 V or battery voltage?


YES - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original  ECM/ PCM.n


NO - Check these items:

  • A short or an open in the wire between the  ECM/ PCM (A18) and the  VSS.
  • If the wire is OK, test the VSS.