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. 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 ECM.
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 17.
12. Jump the SCS line with the HDS.
13. Disconnect ECM connector A (44P).
14. Check for continuity between ECM connector terminal A10 and body ground.
Is there continuity?
YES - Repair short in the wire between the EVAP canister vent shut valve and the ECM (A10), 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 ECM connector terminal A10 and body ground.
Is there continuity?
YES - Go to step 25.
NO - Repair open in the wire between the EVAP canister vent shut valve and the ECM (A10), 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 ECM with the HDS.
21. Do the ECM idle learn procedure. ECM 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 ECM, then go to step 1.
NO - Go to step 24.
24. 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 Temporary DTCs or DTCs were indicated in step 23, 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, then go to step 1. If the screen indicates NOT COMPLETED, go to step 22.
25. Reconnect all connectors.
26. Update the ECM if it does not have the latest software, ECM Update or substitute a known-good ECM. Initial Inspection and Diagnostic Overview
27. Select EVAP CVS ON in the INSPECTION MENU with the HDS.
28. 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 ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then go to step 27. If the ECM was substituted, go to step 1.
NO - Go to step 29.
29. Monitor the OBD STATUS for DTC P0498 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 Temporary DTCs or DTCs were indicated in step 28, 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, Initial Inspection and Diagnostic Overview then go to step 27. If the ECM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 27.