DTC P0497: EVAP System Low Purge Flow

Special Tools Required

Vacuum/pressure gauge, 0-4 in.Hg 07JAZ-001000B
Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

Check the fuel fill cap installation.
Is the fuel fill cap installed and properly tightened ?

YES - Go to step 2.

NO - Properly install and tighten the fuel fill cap 3 clicks, then go to step 24.
Turn the ignition switch 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, system is OK at this time. Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, or the EVAP canister vent shut valve and the PCM.

NO - Go to step 5.
Check for a loose or damaged in the PCS 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 PCS line, then go to step 24.
Disconnect the vacuum hose (A) from the EVAP canister purge valve service port (B) in the engine compartment, and connect a vacuum pump/gauge, 0-30 in.Hg, to the hose.

Fig 1: Disconnecting Vacuum Hose From EVAP Canister Purge Valve Service Port In Engine Compartment
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Do the EVAP PCS ON in the INSPECTION MENU with the HDS.
Slowly apply about 2.0 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.
Does it hold vacuum ?

YES - Replace the EVAP canister purge valve, then go to step 24.

NO - Go to step 9.
Reconnect the vacuum hose to the EVAP service port.
Disconnect the vacuum hose from the PCS line (at the EVAP canister side), and connect a vacuum pump/gauge, 0-30 in.Hg, to the hose.

Fig 2: Disconnecting Vacuum Hose From PCS Line
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Do the EVAP PCS ON in the INSPECTION MENU with the HDS.
Slowly apply about 2 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.
Does it hold vacuum ?

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

NO - Go to step 13.
Remove the FTP sensor with its connector connected (see FTP SENSOR REPLACEMENT ).
Connect a T-fitting (A) from the vacuum gauge and a vacuum pump/gauge, 0-30 in.Hg, to the FTP sensor (B) as shown.

Fig 3: Connecting T-Fitting From Vacuum Gauge And Vacuum Pump/Gauge
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 in.Hg, 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 in.Hg, 8 mmHg) before and after applying vacuum ?

YES - Go to step 18.

NO - Replace the FTP sensor (see FTP SENSOR REPLACEMENT ), then go to step 23.
Reconnect the vacuum hoses to the PCS line (EVAP canister side), and reinstall the FTP sensor.
Disconnect the vacuum hose (A) from the EVAP canister purge valve (B), and connect a vacuum pump/gauge, 0-30 in.Hg, to the hose.

Fig 4: Disconnecting Vacuum Hose From EVAP Canister Purge Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Do the EVAP CVS ON in the INSPECTION MENU with the HDS.
Slowly apply about 2 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.
Does the hose hold vacuum ?

YES - Check for blockage on the EVAP canister port, then go to step 22.

NO - Replace the EVAP canister vent shut valve (see EVAP CANISTER VENT SHUT VALVE REPLACEMENT ), then go to step 22.
Install the FTP sensor (see FTP SENSOR REPLACEMENT ).
Reconnect all hoses.
Turn the ignition switch 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, or the EVAP canister vent shut valve and the PCM, then go to step 1.