DTC Troubleshooting

DTC Troubleshooting: P0499

DTC P0499: EVAP Canister Vent Shut Valve Circuit High Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Reading and Clearing Diagnostic Trouble Codes

1. Turn the ignition switch to ON (II).

2. Clear the DTC with the HDS.

3. Select EVAP CVS ON in the INSPECTION MENU with the HDS.

4. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0499 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EVAP canister vent shut valve and the ECM.


5. Update the ECM if it does not have the latest software, ECM/PCM Update or substitute a known-good ECM. Reading and Clearing Diagnostic Trouble Codes

6. Select EVAP CVS ON in the INSPECTION MENU with the HDS.

7. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0499 indicated?
YES - Check for poor connections or loose terminals at the EVAP canister vent shut valve and the ECM. If the ECM was updated, substitute a known-good ECM, Reading and Clearing Diagnostic Trouble Codes then go to step 6. If the ECM was substituted, go to step 1.

NO - Go to step 8.


8. Monitor the OBD STATUS for DTC P0499 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?
YES - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. Service and Repair If any other Pending or Confirmed DTCs were indicated in step 7, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the EVAP canister vent shut valve and the ECM. If the ECM was updated, substitute a known-good ECM, Reading and Clearing Diagnostic Trouble Codes then go to step 6. If the ECM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 6.