DTC Troubleshooting

Control System DTCs

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 How To Troubleshoot The Fuel And Emissions Systems.

1. EVAP system check:

EVAP system check
-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 3.
-NO- Go to step 2.

2. Problem verification:

Problem verification
-1. Select EVAP CVS ON in the INSPECTION MENU with the HDS.

-2. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0498 indicated?
-YES- The failure is duplicated. Go to step 3.
-NO- The EVAP system is OK. 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.

3. Open wire check (FI_SUB_RLY_OUT line):

Open wire check (FI_SUB_RLY_OUT line)
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





-3. Turn the ignition switch to ON (II).

-4. Measure the voltage between test points 1 and 2.









Is there battery voltage?
-YES- The FI_SUB_RLY_OUT wire is OK. Go to step 4.
-NO- Repair an open in the FI_SUB_RLY_OUT wire between the EVAP canister vent shut valve and the PGM-FI subrelay, then do the repair verification.

4. EVAP canister purge valve internal resistance check:

EVAP canister purge valve internal resistance check
-1. Turn the ignition switch to LOCK (0).

-2. At the vent shut valve side, measure the resistance between test points 1 and 2.









Is there about 25 -30 Ohms at room temperature?
-YES- The EVAP canister vent shut valve is OK. Go to step 5.
-NO- Replace the EVAP canister vent shut valve Service and Repair, then do the repair verification.

5. Shorted wire check (VSV line):

Shorted wire check (VSV line)
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Repair a short in the VSV wire between the EVAP canister vent shut valve and the ECM (A32), then do the repair verification.
-NO- The VSV wire is not shorted. Go to step 6.

6. Open wire check (VSV line):

Open wire check (VSV line)
-1. Connect terminals A and B with a jumper wire.









-2. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The VSV wire is OK. Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then do the repair verification.
-NO- Repair an open in the VSV wire between the EVAP canister vent shut valve and the ECM (A32), then do the repair verification.

Repair verification (OBD STATUS check):

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the ECM with the HDS How To Troubleshoot The Fuel And Emissions Systems.

-5. Do the ECM idle learn procedure ECM/PCM Idle Learn Procedure.

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

-7. Monitor the OBD STATUS for DTC P0498 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?
-PASSED- Troubleshooting is complete. If the ECM was substituted, replace the original ECM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.
-FAILED- Go to step 1 and recheck. If the ECM was updated, substitute a known-good ECM Service and Repair, then check the OBD STATUS again.
-NOT COMPLETED- Meet the test condition, and check the OBD STATUS again.