FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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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.

1. Turn the ignition switch 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 OFF.
7. Disconnect the EVAP canister vent shut valve 2P connector.
8. Turn the ignition switch ON (II).




9. Measure 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 (E), then go to step 18.

10. Turn the ignition switch OFF.




11. Measure resistance between EVAP canister vent shut valve 2P connector terminals No. 1 and No. 2.

Is there about 25 - 30 Ohm 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 24.

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.
18. Reconnect all connectors.
19. Turn the ignition switch ON (II).
20. Reset the ECM with the HDS.
21. Do the 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.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0498 is indicated, check for poor connections or loose terminals at the EVAP canister vent shut valve and the ECM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Troubleshooting is complete.

24. Update the ECM if it does not have the latest software, or substitute a known-good ECM.
25. Select EVAP CVS ON in the INSPECTION MENU with the HDS.
26. 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, then go to step 25. If the ECM was substituted, go to step 1.

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