DTC DETECTION LOGIC NOTE： If DTC P0456 is displayed with DTC P0442, first perform the trouble diagnosis for DTC P0456. This diagnosis detects very small leaks in the EVAP line between fuel tank and EVAP canister purge volume control solenoid valve, using the intake manifold vacuum in the same way as conventional EVAP small leak diagnosis.
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.

DTC No. | Trouble diagnosis name | DTC detecting condition | Possible cause
P0456 | Evaporative emission control system very small leak (negative pressure check) |

- EVAP system has a very small leak.
- EVAP system does not operate properly.

- Incorrect fuel tank vacuum relief valve
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close.
- Foreign matter caught in fuel filler cap.
- Leak is in line between intake manifold and EVAP canister purge volume control solenoid valve.
- Foreign matter caught in EVAP canister vent control valve.
- EVAP canister or fuel tank leaks
- EVAP purge line (pipe and rubber tube) leaks
- EVAP purge line rubber tube bent
- Loose or disconnected rubber tube
- EVAP canister vent control valve and the circuit
- EVAP canister purge volume control solenoid valve and the circuit
- Fuel tank temperature sensor
- O-ring of EVAP canister vent control valve is missing or damaged
- EVAP canister is saturated with water
- EVAP control system pressure sensor
- Refueling EVAP vapor cut valve
- ORVR system leaks
- Fuel level sensor and the circuit
- Foreign matter caught in EVAP canister purge volume control solenoid valve

■ CAUTION ■

- Use only a genuine NISSAN 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 NISSAN rubber tube as a replacement.

DTC CONFIRMATION PROCEDURE
1.INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES>>GO TO 2.
NO>>GO TO 4.
2.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.

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.

NOTE：
After repair, check that the hoses and clips are installed properly.
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.

- Fuel filler cap is removed.
- Fuel is refilled or drained.
- EVAP component part/parts are removed.

- Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.
- Check that EVAP hoses are connected to EVAP canister purge volume control solenoid valve properly.

>>GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III

1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
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 CONSULT-III.Follow the instructions displayed.
   NOTE：
   If the engine speed cannot be maintained within the range displayed on CONSULT-III screen, go to Special Repair Requirement (GT-R certified NISSAN dealer).

Which is displayed on CONSULT-III screen?
OK>>INSPECTION END
NG>>Go to Diagnosis Procedure (GT-R certified NISSAN dealer).
4.PERFORM COMPONENT FUNCTION CHECK
Perform component function check. Refer to Component Function Check (GT-R certified NISSAN dealer).
NOTE：
Use component function check to check the overall function of the EVAP very small leak function. During this check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES>>INSPECTION END
NO>>Go to Diagnosis Procedure (GT-R certified NISSAN dealer).