DTC Troubleshooting

DTC Troubleshooting: P0498

DTC P0498: EVAP Canister Vent Shut Valve Control Circuit Low Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview

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

2. Clear the DTC with the HDS.

3. Check for Temporary DTCs or 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 Temporary DTCs or 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 under-hood fuse/relay box (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 17.






12. Jump the SCS line with the HDS.

13. Disconnect PCM connector A (49P).

14. Check for continuity between PCM connector terminal A22 and body ground.

Is there continuity?
YES - Repair short in the wire between the EVAP canister vent shut valve and the PCM (A22), then go to step 18.

NO - Go to step 15.






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






16. Check for continuity between PCM connector terminal A22 and body ground.

Is there continuity?
YES - Go to step 24.

NO - Repair open in the wire between the EVAP canister vent shut valve and the PCM (A22), then go to step 18.






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

18. Reconnect all connectors.

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

20. Reset the PCM with the HDS.

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

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

23. Check for Temporary DTCs or 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 - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


24. Reconnect all connectors.

25. Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM. Initial Inspection and Diagnostic Overview

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

27. Check for Temporary DTCs or 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, Initial Inspection and Diagnostic Overview then recheck. If the PCM was substituted, go to step 1.

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. Service and Repair If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.