Infiniti EX35. Manual - part 643

EC-314

< COMPONENT DIAGNOSIS >

[VQ35HR]

P0456 EVAP CONTROL SYSTEM

P0456 EVAP CONTROL SYSTEM

DTC Logic

INFOID:0000000003133459

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 there are no leaks, the diagnosis will be OK.

CAUTION:

• Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used, the

MIL may come on.

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 prop-

erly.

• 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 con-

trol 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 miss-

ing 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 vol-

ume control solenoid valve

PBIB1026E

P0456 EVAP CONTROL SYSTEM

EC-315

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• If the fuel filler cap is not tightened properly, the MIL may come on.
• 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 turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
NOTE:
After repair, check that the hoses and clips are installed properly.
TESTING CONDITION:
• Open engine hood before conducting 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 parts is/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 prop-

erly.

>> 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 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 refilling/draining
fuel until the output voltage condition 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 instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on CONSULT-III screen, go to

EC-12, "BASIC INSPECTION : Special Repair Requirement"

.

Which is displayed on CONSULT-III screen?

OK

>> INSPECTION END

NG

>> Go to 

EC-316, "Diagnosis Procedure"

.

4.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to 

EC-316, "Component Function Check"

.

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

EC-316

< COMPONENT DIAGNOSIS >

[VQ35HR]

P0456 EVAP CONTROL SYSTEM

NO

>> Go to 

EC-316, "Diagnosis Procedure"

.

Component Function Check

INFOID:0000000003133460

1.

PERFORM COMPONENT FUNCTION CHECK

With GST

CAUTION:

• Do not use compressed air, doing so may damage the EVAP system.
• Do not start engine.
• Do not exceeded 4.12 kPa (0.042 kg/cm

2

, 0.6 psi).

1.

Attach the EVAP service port adapter securely to the EVAP service port (commercial service tool).

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/cm

2

, 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/cm

2

, 0.06 psi).

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Go to 

EC-316, "Diagnosis Procedure"

.

2.

RELEASE PRESSURE

1.

Disconnect GST.

2.

Start engine and warm it up to normal operating temperature.

3.

Turn ignition switch OFF and wait at least 10 seconds.

4.

Restart engine and let it idle for 90 seconds.

5.

Keep engine speed at 2,000 rpm for 30 seconds.

6.

Turn ignition switch OFF.
NOTE:
For more information, refer to GST Instruction Manual.

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000003133461

1.

CHECK FUEL FILLER CAP DESIGN

1.

Turn ignition switch OFF.

2.

Check for genuine NISSAN fuel filler cap design.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace with genuine NISSAN fuel filler cap.

2.

CHECK FUEL FILLER CAP INSTALLATION

Check that the cap is tightened properly by rotating the cap clockwise.
Is the inspection result normal?

SEF462UI

SEF915U

P0456 EVAP CONTROL SYSTEM

EC-317

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YES

>> GO TO 3.

NO

>> Open fuel filler cap, then clean cap and fuel filler neck threads using air blower. Retighten until

ratcheting sound is heard.

3.

CHECK FUEL FILLER CAP FUNCTION

Check for air releasing sound while opening the fuel filler cap.
Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

CHECK FUEL TANK VACUUM RELIEF VALVE

Refer to 

EC-319, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace fuel filler cap with a genuine one.

5.

CHECK FOR EVAP LEAK

Refer to 

EC-539, "Inspection"

.

Is there any leak in EVAP line?

YES

>> Repair or replace malfunctioning part.

NO

>> GO TO 6.

6.

CHECK EVAP CANISTER VENT CONTROL VALVE

Check the following.
• EVAP canister vent control valve is installed properly.

Refer to 

EC-541, "Removal and Installation"

.

• EVAP canister vent control valve.

Refer to 

EC-288, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Repair or replace EVAP canister vent control valve and O-ring.

7.

CHECK IF EVAP CANISTER SATURATED WITH WATER

1.

Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.

2.

Check if water will drain from EVAP canister (1).

Does water drain from the EVAP canister?

YES

>> GO TO 8.

NO-1

>> With CONSULT-III: GO TO 10.

NO-2

>> Without CONSULT-III: GO TO 11.

8.

CHECK EVAP CANISTER

Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.1 kg (4.6 lb).

Is the inspection result normal?

YES-1 >> With CONSULT-III: GO TO 10.
YES-2 >> Without CONSULT-III: GO TO 11.
NO

>> GO TO 9.

9.

DETECT MALFUNCTIONING PART

Check the following.

2

: EVAP canister vent control valve

PBIB2731E