Nissan Xterra. Manual - part 302

EC-334

< DTC/CIRCUIT DIAGNOSIS >

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P0455 EVAP CONTROL SYSTEM

NG

>> Replace EVAP canister purge volume control solenoid valve. Refer to 

FL-16, "Removal and

Installation"

.

16.

CHECK FUEL TANK TEMPERATURE SENSOR

Refer to 

EC-250, "Component Inspection"

.

OK or NG

OK

>> GO TO 17.

NG

>> Replace fuel level sensor unit. Refer to 

FL-11, "Removal and Installation"

.

17.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-323, "Component Inspection"

.

OK or NG

OK

>> GO TO 18.

NG

>> Replace EVAP control system pressure sensor. Refer to 

FL-16, "Removal and Installation"

.

18.

CHECK EVAP/ORVR LINE

Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kink, looseness and improper con-

nection. For location, refer to 

EC-475, "System Description"

.

OK or NG

OK

>> GO TO 19.

NG

>> Repair or replace hoses and tubes.

19.

CHECK RECIRCULATION LINE

Check recirculation line between filler neck tube and fuel tank for clogging, kink, cracks, looseness and

improper connection.
OK or NG

OK

>> GO TO 20.

NG

>> Repair or replace hose, tube or filler neck tube. Refer to 

FL-6, "Removal and Installation"

.

20.

CHECK REFUELING EVAP VAPOR CUT VALVE

Refer to 

EC-478, "Component Inspection"

.

OK or NG

OK

>> GO TO 21.

NG

>> Replace refueling EVAP vapor cut valve with fuel tank. Refer to 

FL-6, "Removal and Installation"

.

21.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000009484038

FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FILLER CAP)

1. Wipe clean valve housing.

SEF445Y

P0455 EVAP CONTROL SYSTEM

EC-335

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2. Check valve opening pressure and vacuum.

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 incor-

rect fuel filler cap is used, the MIL may come on.

Pressure: 15.3 - 20.0 kPa (0.156 - 0.204 kg/cm

2

, 2.22 - 

2.90 psi)

Vacuum:

−6.0 to −3.3 kPa (−0.061 to −0.034 kg/cm

2

, 

−0.87 to −0.48 psi)

SEF943S

EC-336

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P0456 EVAP CONTROL SYSTEM

P0456 EVAP CONTROL SYSTEM

On Board Diagnosis Logic

INFOID:0000000009484039

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.

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 No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0456
0456

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

PBIB3640E

P0456 EVAP CONTROL SYSTEM

EC-337

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DTC Confirmation Procedure

INFOID:0000000009484040

NOTE:

• If DTC P0456 is displayed with P0442, first perform trouble diagnosis for DTC P0456.

• After repair, make sure that the hoses and clips are installed properly.

• If DTC Confirmation Procedure has been previously conducted, always perform the following before con-

ducting 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.

- Fuel filler cap is removed.

- Fuel is refilled or drained.

- EVAP component part/parts is/are removed.

• Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

 WITH CONSULT

1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT.

2. Check the following conditions are met.

FUEL LEVEL SE: 0.25 - 1.4V

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 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.

Follow the instructions displayed.

6. Check that “OK” is displayed.

If “NG” is displayed, refer to 

EC-338, "Diagnosis Procedure"

.

NOTE:

• If the engine speed cannot be maintained within the range displayed on CONSULT screen, go to

EC-118, "Basic Inspection"

.

• Check that EVAP hoses are connected to EVAP canister purge volume control solenoid valve

properly.

Overall Function Check

INFOID:0000000009484041

 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/cm

2

, 0.6 psi).