Nissan Quest E52. Manual - part 523

EC-302

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0448 EVAP CANISTER VENT CONTROL VALVE

3.

Check air passage continuity and operation delay time.
Check that new O-ring is installed properly.

Operation takes less than 1 second.

Without CONSULT

1.

Clean the air passage [portion (A) to (B)] of EVAP canister vent
control valve using an air blower.

2.

Check air passage continuity and operation delay time under the
following conditions.
Check that new O-ring is installed properly.

Operation takes less than 1 second.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace EVAP canister vent control valve. Refer to 

FL-16, "Exploded View"

.

Condition VENT CONTROL/V

Air passage continuity between (A) and (B)

ON

No

OFF

Yes

Condition

Air passage continuity between (A) and (B)

12 V direct current supply between
 terminals (1) and (2)

No

OFF

Yes

JMBIA0169ZZ

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

EC-303

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

DTC Logic

INFOID:0000000009651137

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

NOTE:
Never remove fuel filler cap during DTC confirmation procedure.

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
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.

With CONSULT>>GO TO 2.
Without CONSULT>>GO TO 5.

2.

PERFORM DTC CONFIRMATION PROCEDURE-1

With CONSULT

1.

Start engine and let it idle for least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-304, "Diagnosis Procedure"

.

NO

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE-2

With CONSULT

1.

Select “EVAP DIAG READY” in “DATA MONITOR” mode of “ENGINE”.

2.

Let it idle until “OFF” of “EVAP DIAG READY” changes to “ON”.
NOTE:
It will take at most 2 hours until “OFF” of “EVAP DIAG READY” changes to “ON”.

3.

Turn ignition switch OFF and wait at least 90 minutes.
NOTE:
Never turn ignition switch ON during 90 minutes.

4.

Turn ignition switch ON.

5.

Select “EVAP LEAK DIAG” in “DATA MONITOR” mode of “ENGINE”.

6.

Check that “EVAP LEAK DIAG” indication.

Which is displayed on CONSULT?

CMPLT >> GO TO 4.
YET

>> 1.

Perform DTC CONFIRMATION PROCEDURE again.

2.

GO TO 1.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0451

EVAP control system 
pressure sensor perfor-
mance

ECM detects a sloshing signal from the EVAP 
control system pressure sensor

• Harness or connectors

(EVAP control system pressure sensor 
circuit is shorted.)
[CKP sensor (POS) circuit is shorted.]
(APP sensor 2 circuit is shorted.)
(Refrigerant pressure sensor circuit is 
shorted.)

• EVAP control system pressure sensor
• Crankshaft position sensor (POS)
• Accelerator pedal position sensor
• Refrigerant pressure sensor

EC-304

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

4.

PERFORM DTC CONFIRMATION PROCEDURE-3

With CONSULT

Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Proceed to 

EC-304, "Diagnosis Procedure"

.

NO

>> INSPECTION END

5.

PERFORM DTC CONFIRMATION PROCEDURE-4

With GST

1.

Start engine and let it idle for least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-304, "Diagnosis Procedure"

.

NO

>> GO TO 6.

6.

PERFORM DTC CONFIRMATION PROCEDURE-5

With GST

1.

Let it idle for at least 2 hours.

2.

Turn ignition switch OFF and wait at least 90 minutes.
NOTE:
Never turn ignition switch ON during 90 minutes.

3.

Turn ignition switch ON.

4.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-304, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009651138

1.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER

1.

Disconnect EVAP control system pressure sensor harness connector.

2.

Check that water is not inside connectors.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace harness connector.

2.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY

1.

Turn ignition switch ON.

2.

Check the voltage between EVAP control system pressure sensor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 3.

3.

CHECK SENSOR POWER SUPPLY CIRCUIT

Check harness for short to power and short to ground, between the following terminals.

EVAP control system pressure sensor

Ground

Voltage (V)

Connector

Terminal

B22

3

Ground

Approx. 5

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

EC-305

< DTC/CIRCUIT DIAGNOSIS >

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Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair short to ground or short to power in harness or connectors.

4.

CHECK COMPONENTS

Check the following.
• Crankshaft position sensor (POS) (Refer to 

EC-273, "Component Inspection"

.)

• Refrigerant pressure sensor (Refer to 

EC-442, "Diagnosis Procedure"

.)

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace malfunctioning components.

5.

CHECK APP SENSOR

Check APP sensor. Refer to 

EC-405, "Component Inspection"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-42, "Intermittent Incident"

.

NO

>> Replace accelerator pedal assembly. Refer to 

ACC-3, "Exploded View"

.

6.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Check EVAP control system pressure sensor. Refer to 

EC-305, "Component Inspection"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-42, "Intermittent Incident"

.

NO

>> Replace EVAP control system pressure sensor. Refer to 

FL-16, "Exploded View"

.

Component Inspection

INFOID:0000000009651139

1.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

1.

Turn ignition switch OFF.

2.

Remove EVAP control system pressure sensor with its harness connector. Refer to 

FL-16, "Exploded

View"

.

Always replace O-ring with a new one.

3.

Install a vacuum pump to EVAP control system pressure sensor.

4.

Turn ignition switch ON and check output voltage between ECM terminals under the following conditions.

CAUTION:

• Always calibrate the vacuum pump gauge when using it.
• Never apply below -93.3 kPa (-0.952 kg/cm

2

, -13.53 psi) or pressure over 101.3 kPa (1.033 kg/cm

2

,

14.69 psi).

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace EVAP control system pressure sensor. Refer to 

FL-16, "Exploded View"

.

ECM

Sensor

Connector

Terminal

Name

Connector

Terminal

F8

96

Refrigerant pressure sensor

E300

1

54

CKP sensor (POS)

F20

1

E16

103

APP sensor

E110

5

107

EVAP control system pressure sensor

B22

3

ECM

Applied vacuum kPa

(kg/cm

2

, psi)

Voltage

Connector

+

–

Terminal

Terminal

E16

102

(EVAP control system 

pressure sensor signal)

112

(Sensor ground)

Not applied

1.8 - 4.8 V

-26.7 (-0.272, -3.87)

2.1 to 2.5 V lower than 

above value