DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P0497

DTC P0497 : EVAP System Low 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:

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

-2. Clear the DTC with the HDS.

-3. Do the EVAP FUNCTION TEST with the HDS.

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 ECM/PCM.
-NO- The failure is duplicated. Go to step 2.

2. EVAP canister purge line visual check:

EVAP canister purge line visual check
-1. Turn the ignition switch to LOCK (0).

-2. Check for a poor connection, a blockage, or damage at the EVAP canister purge line between throttle body and the EVAP canister.

Is the line OK?
-YES- Go to step 3.
-NO- Reconnect or repair the EVAP canister purge line, then do the repair verification.

3. Determine possible failure area (EVAP canister purge valve, others):

Determine possible failure area (EVAP canister purge valve, others)
-1. Disconnect the vacuum hose (purge line) (A) from the EVAP canister purge valve (B) in the engine compartment, then connect a T-fitting (C), a vacuum gauge, and a vacuum pump/gauge, 0-30 inHg, to the vacuum hose as shown.





-2. Turn the ignition switch to ON (II).

-3. Select EVAP PCS ON in the INSPECTION MENU with the HDS.

-4. Slowly apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the hose.

Does it hold vacuum?
-YES- Replace the EVAP canister purge valve Service and Repair, then do the repair verification.
-NO- Go to step 4.

4. Determine possible failure area (EVAP canister purge line, others):

Determine possible failure area (EVAP canister purge line, others)
-1. Reconnect the vacuum hose to the EVAP canister purge valve.

-2. Disconnect the vacuum hose (A) from the purge line (at the EVAP canister side), then connect the T-fitting (C), the vacuum gauge, and the vacuum pump/gauge to the hose as shown.





-3. Select EVAP PCS ON in the INSPECTION MENU with the HDS.

-4. Apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the purge valve.

Does it hold vacuum?
-YES- Check for a blockage in the purge line between the EVAP canister purge valve and the EVAP canister, then do the repair verification.
-NO- Go to step 5.

5. FTP sensor performance check:

FTP sensor performance check
-1. Turn the ignition switch to LOCK (0).

-2. Remove the FTP sensor with its connector connected.

-3. Connect the the T-fitting (A), the vacuum pump/gauge, and the vacuum gauge to the FTP sensor (B) as shown.





-4. Turn the ignition switch to ON (II).

-5. Check and record the FTP SENSOR reading in the DATA LIST with the HDS.

-6. Slowly apply about 1.3 kPa (0.4 inHg, 10 mmHg) of vacuum to the hose.

-7. Check the FTP SENSOR in the DATA LIST with the HDS.

Does the value change?
-YES- Go to step 6.
-NO- Replace the FTP sensor Service and Repair, then do the repair verification.

6. EVAP canister purge line check:

EVAP canister purge line check
-1. Reconnect the vacuum hoses to the EVAP canister purge line (EVAP canister side), and reinstall the FTP sensor.

-2. Disconnect the vacuum hose (purge line) (A) from the EVAP canister purge valve (B) in the engine compartment, then connect the T-fitting (C), the vacuum gauge, and the vacuum pump/gauge to the vacuum hose as shown.





-3. Select EVAP CVS ON in the INSPECTION MENU with the HDS.

-4. Slowly apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the hose.

Does the hose hold vacuum?
-YES- Check for a blockage at the EVAP canister port, then do the repair verification.
-NO- Replace the EVAP canister vent shut valve Service and Repair, then do the repair verification.

Repair verification:

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

-2. Install the parts in the reverse order of removal.

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

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

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

-6. Do the EVAP 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 ECM/PCM, then go to step 1.