DTC P04F1 (1.5 L Engine)

DTC P04F1  : 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, review the general troubleshooting information .

DTC (PGM-FI)

1. Problem verification

   -1. Turn the vehicle to the ON mode.

   -2. Clear the DTC with the HDS.

   -3. Select the EVAP TEST in the Function Test, then select the FUNCTION TEST with the HDS.

   EVAP TEST - FUNCTION TEST

   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. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot .

   NO 

   The failure is duplicated. Go to step 2.

2. EVAP canister purge line visual check

   -1. Turn the vehicle to the OFF (LOCK) mode.

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

   Is the line OK?

   YES 

   Go to step 3.

   NO 

   Reconnect or repair the EVAP canister purge line.

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

   -1. Remove the EVAP canister purge valve with its connector and vacuum hose connected.

   -2. Disconnect the vacuum hose (purge line) (A) from the EVAP canister purge valve (B).

   Courtesy of HONDA, U.S.A., INC.

   -3. Disconnect the EVAP canister purge line (A) from the EVAP canister (B). Connect the T-fitting (C), the vacuum gauge, and the vacuum pump/gauge, 0-30 inHg to the EVAP canister purge line as shown.

   Courtesy of HONDA, U.S.A., INC.

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

   Does the hose hold vacuum?

   YES 

   Check for a blockage in the EVAP purge line between the EVAP canister purge valve and the EVAP canister.

   NO 

   Go to step 4.

4. EVAP canister purge valve check

   -1. Inspect the EVAP canister purge valve .

   Is the EVAP canister purge valve OK?

   YES 

   Go to step 5.

   NO 

   Replace the EVAP canister purge valve .

5. Purge tube A check

   -1. Connect the vacuum pump/gauge, 0-30 inHg, to purge tube A as shown.

   Courtesy of HONDA, U.S.A., INC.

   -2. Start the engine, and let it idle.

   Is there vacuum?

   YES 

   Go to step 6.

   NO 

   Check for blockage at purge tube A between the intake manifold and the EVAP canister purge valve.

6. FTP sensor performance check

   -1. Turn the vehicle to the OFF (LOCK) mode.

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

   -3. Connect the T-fitting (A) to the vacuum pump/gauge, 0-30 inHg, and the vacuum gauge to the FTP sensor (B) as shown.

   Courtesy of HONDA, U.S.A., INC.

   -4. Turn the vehicle to the ON mode.

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

   Signal	Current conditions
   	Values	Unit
   FTP Sensor

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

   NOTE:  Be careful not to exceed the vacuum. If you do, the FTP sensor can be damaged.

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

   Signal	Current conditions
   	Values	Unit
   FTP Sensor

   Does the value change?

   YES 

   Go to step 7.

   NO 

   Replace the FTP sensor .

7. EVAP canister purge line check

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Reconnect the EVAP canister purge line to the EVAP canister, and reinstall the FTP sensor .

   -3. 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, 0-30 inHg, to the vacuum hose as shown.

   Courtesy of HONDA, U.S.A., INC.

   -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 purge line port.

   NO 

   Replace the EVAP canister vent shut valve .