DTC Troubleshooting: P0456(3.0L Engine): Inspection

EVAP Purge System Inspection (Leakage) 

Preconditions 

• EVAP canister purge valve is normal

Test Procedure 

• Procedure
• • Disconnect the fuel purge pipe (A) from the EVAP canister (B).
  • Connect the hose (C) to the fuel purge pipe, then connect the vacuum pump/gauge, 0-30 inHg (D) to the hose as shown.
  • Apply vacuum to the hose.

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

• Normal Conditions
• • -

    Vacuum is held.

Results 

• If it is abnormal, there is a problem with the EVAP purge system.

ELCM System 1 Inspection (Leakage) 

Test Procedure 

• Procedure
• • -

    Check for a poor connection, leakage or any damage on the ELCM system component (A).

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

• Normal Conditions
• • -

    Connection conditions are OK, and there is no leakage or damage.

Results 

• If it is abnormal, there is a problem with ELCM system 1.

ELCM System 2 Inspection (Blockage) 

Test Procedure 

• Procedure
• • Disconnect the drain tube (A) from the EVAP leak check module (B).
  • Connect the hose (C) to the drain tube, then connect the vacuum pump/gauge, 0-30 inHg (D) to the hose as shown.
  • Apply pressure to the hose.

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

• Normal Conditions
• • -

    Pressure is not held.

Results 

• If it is abnormal, there is a problem with ELCM system 2.

Main Flap Unit Inspection 

Test Procedure 

• Preparation
• • -

    Mis-fuel inhibit device: removed

• Procedure
• • -

    Check the shut-off valve (A) is closed, and inspect the flap seal of the shut-off valve (B) and the mating surface of the shut-off valve for missing or damage.

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

• Normal Conditions
• • -

    The shut-off valve is closed, and there is no missing or damaged seals.

Results 

• If it is abnormal, there is a problem with the main flap unit.

Fuel Tank System Inspection (Leakage) 

Preconditions 

• Main flap unit is normal

Test Procedure 

• Procedure
• • Disconnect the fuel vent tube (A) from the EVAP canister (B), and connect the vacuum pump/gauge, 0-30 inHg (C) to the tube.
  • Apply vacuum to the fuel vent tube.

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

• Normal Conditions
• • -

    Vacuum is held.

Results 

• If it is abnormal, there is a problem with the fuel tank system.

EVAP Canister Inspection (Leakage) 

Test Procedure 

• Procedure
• • Disconnect the drain tube (A), the fuel vent tube (B), and the fuel purge pipe (C) from the EVAP canister (D), then plug the drain tube port (E) and the fuel vent tube port (F).
  • Connect the hose (G) to the fuel purge pipe port (H), then connect the vacuum pump/gauge, 0-30 inHg (I) to the hose as shown.
  • Apply vacuum to the hose.

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

• Normal Conditions
• • -

    Vacuum is held.

Results 

• If it is abnormal, there is a problem with the EVAP canister.

EVAP Leak Check Module Inspection 

Test Procedure 

• If the other inspection item(s) indicated a normal condition, then it is determined that the remaining EVAP leak check module is the cause.

Results 

• There is a problem with the EVAP leak check module.