DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P0496

DTC P0496 : EVAP System High Purge Flow Detected

Special Tools Required

*Vacuum Pump/Gauge, 0-30 inHg Snap-on YA4000A or equivalent, commercially available
*Vacuum/Pressure Gauge, 0-4 inHg 07JAZ-001000B
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. Problem verification:

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

-2. Clear the DTC with the HDS. How to Troubleshoot the Fuel And Emissions Systems

-3. Select the EVAP TEST in the INSPECTION MENU, and do the FUNCTION TEST with the HDS.
NOTE: If the test could not be completed because of another DTC, do the troubleshooting for that DTC.

Is the result OK?
-YES- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, the EVAP canister vent shut valve, and the PCM.
-NO- Go to step 2.

2. EVAP canister purge valve open stuck check:

-1. Select EVAP TEST in the INSPECTION MENU, and do the EVAP PCS OFF in the SINGLE SOLENOID with the HDS.

-2. Disconnect the vacuum hose (A) from the EVAP canister purge valve (B). Connect a T-fitting (C), a vacuum gauge, and a vacuum pump/gauge, 0-30 inHg, to the EVAP canister purge valve as shown.





-3. Apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the purge control solenoid valve.

-4. Do the EVAP PCS ON in the SINGLE SOLENOID with the HDS.

Does the vacuum release immediately?
-YES- Replace the EVAP canister vent shut valve Service and Repair, then do the repair verification.
-NO- Replace the EVAP canister purge valve Service and Repair, then do the repair verification.

Repair verification:

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

-2. Reset the PCM with the HDS How to Troubleshoot the Fuel And Emissions Systems.

-3. Do the PCM idle learn procedure PCM Idle Learn Procedure.

-4. Select the EVAP TEST in the INSPECTION MENU, and do the FUNCTION TEST with the HDS.

Is the result OK?
-YES- Troubleshooting is complete.
-NO- Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, the EVAP canister vent shut valve, and the PCM. then go to step 1.