DTC Troubleshooting

DTC Troubleshooting: P0498

DTC P0498: EVAP Canister Vent Shut Valve Circuit Low 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. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0498 indicated?
YES - Go to step 6.

NO - Go to step 4.


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

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

Is DTC P0498 indicated?
YES - Go to step 6.

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 PCM.


6. Turn the ignition switch to LOCK (0).

7. Disconnect the EVAP canister vent shut valve 2P connector.

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

9. Measure the voltage between EVAP canister vent shut valve 2P connector terminal No. 2 and body ground.

Is there battery voltage?
YES - Go to step 10.

NO - Repair open in the wire between the EVAP canister vent shut valve and the PGM-FI subrelay, then go to step 18.






10. Turn the ignition switch to LOCK (0).

11. At the valve side, measure the resistance between EVAP canister vent shut valve 2P connector terminals No. 1 and No. 2.

Is there about 25-30 Ohms at room temperature?
YES - Go to step 12.

NO - Go to step 18.






12. Turn the ignition switch to LOCK (0).

13. Jump the SCS line with the HDS.

14. Disconnect PCM connector E (31P).

15. Check for continuity between PCM connector terminal E10 and body ground.

Is there continuity?
YES - Repair short in the wire between the EVAP canister vent shut valve and the PCM (E10), then go to step 19.

NO - Go to step 16.






16. Connect EVAP canister vent shut valve 2P connector terminal No. 1 to body ground with a jumper wire.






17. Check for continuity between PCM connector terminal E10 and body ground.

Is there continuity?
YES - Go to step 26.

NO - Repair open in the wire between the EVAP canister vent shut valve and the PCM (E10), then go to step 19.






18. Replace the EVAP canister vent shut valve. Service and Repair

19. Reconnect all connectors.

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

21. Reset the PCM with the HDS.

22. Do the PCM idle learn procedure. PCM Idle Learn Procedure

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

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

Is DTC P0498 indicated?
YES - Check for poor connections or loose terminals at the EVAP canister vent shut valve and the PCM, then go to step 1.

NO - Go to step 25.


25. Monitor the OBD STATUS for DTC P0498 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 24, 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 PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 23.


26. Reconnect all connectors.

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

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

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

Is DTC P0498 indicated?
YES - Check for poor connections or loose terminals at the EVAP canister vent shut valve and the PCM. If the PCM was updated, substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then go to step 28. If the PCM was substituted, go to step 1.

NO - Go to step 30.


30. Monitor the OBD STATUS for DTC P0498 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. Service and Repair If any other Pending or Confirmed DTCs were indicated in step 29, 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 PCM. If the PCM was updated, substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then go to step 28. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 28.