Nissan Altima L32. Manual - part 425

P0448 EVAP CANISTER VENT CONTROL VALVE

EC-821

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

4. Check air passage continuity and operation delay time.

Make sure new O-ring is installed properly.

Operation takes less than 1 second.

Without CONSULT-III

Check air passage continuity and operation delay time under the fol-

lowing conditions.

Make sure 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

3.

CHECK EVAP CANISTER VENT CONTROL VALVE-III

With CONSULT-III

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

2. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.

3. Check air passage continuity and operation delay time.

Make sure new O-ring is installed properly.

Operation takes less than 1 second.

Without CONSULT-III

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.

Make sure new O-ring is installed properly.

Operation takes less than 1 second.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 3.

Condition VENT CONTROL/V

Air passage continuity between (A) and (B)

ON

Not existed

OFF

Existed

Condition

Air passage continuity between (A) and (B)

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

Not existed

OFF

Existed

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Condition VENT CONTROL/V

Air passage continuity between (A) and (B)

ON

Not existed

OFF

Existed

Condition

Air passage continuity between (A) and (B)

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

Not existed

OFF

Existed

JMBIA0169ZZ

EC-822

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

Description

INFOID:0000000004349782

The EVAP control system pressure sensor detects pressure in the

purge line. The sensor output voltage to the ECM increases as pres-

sure increases.

DTC Logic

INFOID:0000000004349783

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

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.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Start engine and wait at least 40 seconds.

NOTE:

Do not depress accelerator pedal even slightly.

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

YES

>> Go to 

EC-822, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000004349784

1.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to Ground Inspection in 

GI-45, "Circuit Inspection"

.

Is the inspection result normal?

PBIB3370E

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.)
[Crankshaft position sensor (POS) circuit 
is shorted.]
(Accelerator pedal position sensor 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

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

EC-823

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER

1. Disconnect EVAP control system pressure sensor harness connector.

2. Check sensor harness connector for water.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness connector.

3.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT

1. Turn ignition switch ON.

2. Check the voltage between EVAP control system pressure sen-

sor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> GO TO 4.

4.

CHECK SENSOR POWER SUPPLY CIRCUITS

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

Is the inspection result normal?

YES

>> GO TO 5.

NO

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

5.

CHECK COMPONENTS

Check the following.

• Crankshaft position sensor (POS) (Refer to 

EC-786, "Component Inspection"

.)

• Refrigerant pressure sensor (Refer to 

EC-975, "Diagnosis Procedure"

.)

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace malfunctioning component.

6.

CHECK APP SENSOR

Refer to 

EC-926, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> GO TO 7.

7.

REPLACE ACCELERATOR PEDAL ASSEMBLY

1. Replace accelerator pedal assembly

2. Go to 

EC-926, "Special Repair Requirement"

.

Water should not exist.

EVAP control system pressure sensor

Ground

Voltage

Connector

Terminal

B41

3

Ground

Approx. 5V

PBIB0138E

ECM

Sensor

Connector

Terminal

Name

Connector

Terminal

F13

72

Refrigerant pressure sensor

E219

1

76

CKP sensor (POS)

F30

1

E10

87

APP sensor

E40

6

91

EVAP control system pressure sensor

B41

3

EC-824

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

>> INSPECTION END

8.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-824, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Replace EVAP control system pressure sensor.

9.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004349785

1.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

1. Turn ignition switch OFF.

2. Remove EVAP control system pressure sensor with its harness connector connected from EVAP canister.

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

harness connector and ground under the following conditions.

CAUTION:

• Always calibrate the vacuum pump gauge when using it.
• Do not 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

ECM

Condition

[Applied vacuum kPa 

(kg/cm

2

, psi)

Voltage

Connector

Terminal

E10

86 

(EVAP control system 

pressure sensor signal)

Not applied

1.8 - 4.8V

-26.7 (-0.272, -3.87)

2.1 to 2.5V lower 

than above value

JMBIA1595ZZ