P0456
P0456 EVAP Control SystemOn Board Diagnosis Logic
This diagnosis detects very small leaks in the EVAP line between fuel tank and EVAP canister purge volume control solenoid valve, using the negative pressure. If ECM judges a leak which corresponds to a very small leak, the very small leak P0456 will be detected.
If ECM judges a leak equivalent to a small leak, EVAP small leak P0442 will be detected.
If ECM judges that there are no leaks, the diagnosis will be OK.
P0456:
CAUTION:
- Use only a genuine fuel filler cap as a replacement. If an incorrect fuel filler cap is used, the MIL may illuminate.
- If the fuel filler cap is not tightened properly, the MIL may illuminate.
- Use only a genuine rubber tube as a replacement.
DTC Confirmation Procedure
NOTE:
- If DTC P0456 is displayed with P0442, first perform trouble diagnosis for DTC P0456.
- After repair, check that the hoses and clips are installed properly.
- If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
- Open engine hood before conducting the following procedure.
- If any of following conditions are met just before the DTC confirmation procedure, leave the vehicle for more than 1 hour.
a. Fuel filler cap is removed.
b. Fuel is refilled or drained.
c. EVAP component part/parts is/are removed.
- Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.
WITH SDT
1. Turn ignition switch ON and select "Data list" mode with SDT.
2. Check that the following conditions are met.
FUEL LEVEL SE: 0.25 - 1.4 V
COOLAN TEMP/S: 0 - 32 °C (32 - 90 °F)
FUEL T/TMP SE: 0 - 35 °C (32 - 95 °F)
INT A/TEMP SE: More than 0 °C (32 °F)
If NG, turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle), or refill/drain fuel until the output voltage of the "FUEL LEVEL SE" meets within the range above and leave the vehicle for more than 1 hour. Then start from step 1.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. Select "EVP V/S LEAK P0456/P1456" of "EVAPORATIVE SYSTEM" in "DTC work support" mode with SDT.
Follow the instruction displayed.
6. Check that "OK" is displayed.
If "NG" is displayed, refer to [P0456 EVAP Control System].
NOTE:
- If the engine speed cannot be maintained within the range displayed on SDT screen, go to [Basic Inspection]. Basic Inspection
- Check that EVAP hoses are connected to EVAP canister purge volume control solenoid valve properly.
Overall Function Check
WITH GST
Use this procedure to check the overall function of the EVAP very small leak function. During this check, a 1st trip DTC might not be confirmed.
CAUTION:
- Never use compressed air, doing so may damage the EVAP system.
- Never start engine.
- Never exceeded 4.12 kPa (0.042 kg/cm2, 0.6 psi).
1. Attach the EVAP service port adapter securely to the EVAP service port.
2. Set the pressure pump and a hose.
3. Also set a vacuum gauge via 3-way connector and a hose.
4. Turn ignition switch ON.
5. Connect GST and select Service $08.
6. Using Service $08 control the EVAP canister vent control valve (close).
7. Apply pressure and check the following conditions are satisfied.
Pressure to be applied: 2.7 kPa (0.028 kg/cm2, 0.39 psi)
Time to be waited after the pressure drawn in to the EVAP system and the pressure to be dropped: 60 seconds and the pressure should not be dropped more than 0.4 kPa (0.004 kg/cm2, 0.06 psi).
If NG, go to [P0456 EVAP Control System].
If OK, go to next step.
8. Disconnect GST.
9. Start engine and warm it up to normal operating temperature.
10. Turn ignition switch OFF and wait at least 10 seconds.
11. Turn ignition switch ON.
12. Turn ignition switch OFF and wait at least 10 seconds.
13. Restart engine and let it idle for 90 seconds.
14. Keep engine speed at 2,000 rpm for 30 seconds.
15. Turn ignition switch OFF.
NOTE: For more information, refer to GST instruction manual.
Diagnosis Procedure
Step 1-6:
Step 7-8:
Step 9-13:
Step 14-24:
Component Inspection
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FILLER CAP)
1. Wipe clean valve housing.
2. Check valve opening pressure and vacuum.
Pressure: 15.3 - 20.0 kPa (0.156 - 0.204 kg/cm2, 2.22 - 2.90 psi)
Vacuum: -6.0 to -3.3 kPa (-0.061 to -0.034 kg/cm2, -0.87 to -0.48 psi)
3. If out of specification, replace fuel filler cap as an assembly.
CAUTION: Use only a genuine fuel filler cap as a replacement. If an incorrect fuel filler cap is used, the MIL may come on.