DTC P0497: EVAP System Low Purge Flow Detected

Special Tools Required

Vacuum/Pressure Gauge, 0-4 inHg 07JAZ-001000B
Vacuum Pump/Gauge, 0-30 inHg Snap-on YA4000A or equivalent, commercially available
Fuel Pressure Gauge Attachment Set 07AAJ-S6MA150

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Do the EVAP FUNCTION TEST in the INSPECTION MENU 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 PCM.

NO -Go to step 4.
Turn the ignition switch to LOCK (0).
Check for a loose or damaged EVAP canister purge line between the intake manifold and the EVAP canister purge valve.
Is the line OK?

YES -Go to step 6.

NO -Reconnect or repair the EVAP canister purge line, then go to step 24.
Disconnect the vacuum hose (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.

Fig 1: Identifying Vacuum Hose, EVAP Canister Purge Valve And T-Fitting
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Select EVAP PCS ON in the INSPECTION MENU with the HDS.
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, then go to step 23.

NO -Go to step 10.
Reconnect the vacuum hose to the EVAP canister purge valve.
Disconnect the vacuum hose (A) from the purge line (at the EVAP canister side), then connect a T-fitting (B), the vacuum gauge, and the vacuum pump/gauge to the hose as shown.

Fig 2: Identifying Connection Of Vacuum Hose, T-Fitting And Vacuum Gauge
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Select EVAP PCS ON in the INSPECTION MENU with the HDS.
Slowly apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the hose.
Does it hold vacuum?

YES -Check for a restricted EVAP canister purge line between the EVAP canister purge valve and the EVAP canister, then go to step 23.

NO -Go to step 14.
Remove the FTP sensor with its connector connected (see FTP SENSOR REPLACEMENT ).
Connect a T-fitting (A), the vacuum pump/gauge, and the vacuum pump to the FTP sensor (B) as shown.

Fig 3: Identifying Connection Of Vacuum Pump/Gauge And Vacuum Pump With FTP Sensor
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check and record the FTP SENSOR reading in the DATA LIST with the HDS.
Slowly apply about 1.3 kPa (0.4 inHg, 10 mmHg) of vacuum to the hose.
Check the FTP SENSOR in the DATA LIST with the HDS.
Is the difference more than 1.1 kPa (0.31 inHg, 8 mmHg) before and after applying vacuum?

YES -Go to step 19.

NO -Replace the FTP sensor (see FTP SENSOR REPLACEMENT ), then go to step 23.
Reconnect the vacuum hoses to the EVAP canister purge line (EVAP canister side), and reinstall the FTP sensor.
Disconnect the vacuum hose (purge line) (A) from the EVAP canister purge valve (B), then connect a T-fitting (C), the vacuum gauge, and the vacuum pump/gauge to the vacuum hose (purge line) as shown.

Fig 4: Identifying Connection Of T-Fitting, Vacuum Gauge And Vacuum Pump/Gauge With Vacuum Hose
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Select EVAP CVS ON in the INSPECTION MENU with the HDS.
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 go to step 23.

NO -Replace the EVAP canister vent shut valve (see EVAP CANISTER VENT SHUT VALVE REPLACEMENT ), then go to step 23.
Reconnect all hoses.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
Do the EVAP FUNCTION TEST in the INSPECTION MENU 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.