DTC P0497: EVAP System Low Purge Flow
CAUTION:
When substituting or replacement of PCM is recommended, see PCM REMOVAL & REPLACEMENT
for important precautions.
NOTE:
Special tools required:
- Vacuum Pump/Gauge, 0-30 in.Hg (A973X-041-XXXXX)
- Vacuum/Pressure Gauge, 0-4 in.Hg (07JAZ-001000B)
- Inspect fuel filler cap, seal and filler neck seal surface. Cap must be tightened at least three clicks to seal system. Replace if necessary. If fuel filler cap and fuel fill pipe is okay, go to next step.
- Turn ignition on. Using Honda PGM Tester or the HDS, do the DTC CLEAR in the CLEAR menu. Turn ignition off.
- Using Honda PGM Tester or the HDS, do the EVAP FUNCTION test in the INSPECTION menu.
- If EVAP SYSTEM is NORMAL, problem is intermittent, system is OK at this time. Check for poor connections and loose terminals at FTP sensor, EVAP bypass solenoid valve, EVAP canister purge valve, or EVAP canister vent shut valve and PCM connectors. If EVAP SYSTEM is not NORMAL, go to next step.
- Check for looseness or damage on PCS line between intake manifold and EVAP canister purge valve. If line is OK, go to next step. If line is not OK, reconnect or repair PCS line. Go to step 21 .
- Disconnect PCS hose at purge joint (A) and connect vacuum pump to the hose (B). See Fig 1 . Connect a T-fitting (C) from vacuum gauge and vacuum pump to the PCS hose (A).
- Turn ignition on. Using Honda PGM Tester or the HDS, do the EVAP PCS OFF in the INSPECTION menu.
- Slowly apply 0.6 in.Hg of vacuum to hose. If it holds vacuum, go to next step. If it does not hold vacuum, check for looseness or damage between EVAP canister purge valve and EVAP canister. Go to step 21 .
- Turn ignition on. Using Honda PGM Tester or the HDS, do the EVAP PCS ON in the INSPECTION menu.
- If the vacuum changes to atmospheric pressure, go to next step. If the vacuum does not change to atmospheric pressure, check for clogged PCS line between EVAP canister purge valve and EVAP canister. Go to step 21 .
- Disconnect vacuum hose (A) from FTP sensor (B). See Fig 1 . Disconnect vacuum hose (A) between EVAP canister (B) and EVAP 2-way valve (C) at EVAP canister side. Connect a T-fitting (D) from vacuum gauge and vacuum pump to the PCS hose (A).
- Slowly apply 0.6 in.Hg of vacuum to hose. If it holds vacuum, go to next step. I fit does not hold vacuum, Reconnect or repair vacuum hose between EVAP canister and EVAP 2-way valve. Go to step 21 .
- Turn ignition on. Using Honda PGM Tester or the HDS, do the EVAP PCS ON in the INSPECTION menu.
- If the vacuum changes to atmospheric pressure, go to next step. If the vacuum does not change to atmospheric pressure, check for clogged vacuum hose between EVAP canister and EVAP 2-way valve and between EVAP 2-way valve and FTP sensor. If vacuum hoses are OK, replace EVAP 2-way valve. Go to step 21 .
- Connect a vacuum pump to hose disconnected from FTP sensor. Slowly apply 0.6 in.Hg of vacuum to hose. If it holds vacuum, go to next step. If it does not hold vacuum, reconnect or repair vacuum hose between EVAP 2-way valve and FTP sensor. Go to step 21 .
- Connect a T-fitting (A) from vacuum gauge and vacuum pump to FTP sensor as shown in Fig 2 . Slowly apply 0.4 in.Hg of vacuum to FTP sensor. Go to next step.
- Turn ignition on. Using Honda PGM Tester or the HDS, check the FTP SENSOR in the DATA list. If the difference is 1.1 kPa (0.31 in.Hg) or more, go to next step. If the difference is 1.1 kPa (0.31 in.Hg) or less, replace FTP sensor. Go to step 21 Disconnect vacuum hose (A) to EVAP 2-way valve (B) at the EVAP canister (C) side and plug the EVAP canister port (D). See Fig 2 . Disconnect PCS hose (E) from EVAP canister (C). Connect T-fitting (F) from vacuum gauge and vacuum pump to PCS hose (E).
- Turn ignition on. Using Honda PGM Tester or the HDS, do the EVAP PCS OFF in the INSPECTION menu.
- Using Honda PGM Tester or the HDS, do the EVAP PCS ON in the INSPECTION menu.
- Slowly apply 0.6 in.Hg of vacuum to hose. If it holds vacuum, check for a clogged EVAP canister port. Go to next step. If it does not hold vacuum, replace the EVAP canister vent shut valve.
- Turn ignition on.
- Turn ignition on. With the Honda PGM tester or the HDS, do PCM RESET in the CLEAR menu. Do the PCM idle learn procedure. See PCM IDLE LEARN PROCEDURE . Go to next step.
- Using Honda PGM Tester or the HDS, do the EVAP FUNCTION test in the INSPECTION menu.
- If EVAP SYSTEM is NORMAL, troubleshooting is complete. If EVAP SYSTEM is not NORMAL, reconnect or repair fuel tank vapor control vent tube and hose between EVAP vent shut valve and EVAP canister. If hoses and tubes are OK, check for poor connections and loose terminals at FTP sensor, EVAP bypass solenoid valve, EVAP canister purge valve, or EVAP canister vent shut valve and PCM connectors. Go to step 1 .