Infiniti FX35, FX50 (S51). Manual - part 693

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

EC-313

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

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5.

CHECK COMPONENTS

Check the following.
• CKP sensor (Refer to 

EC-271, "Component Inspection"

.)

• CMP sensor (bank 2) (Refer to 

EC-277, "Component Inspection"

.)

• EVT control position sensor (bank 2) (Refer to 

EC-369, "Component Inspection"

.)

• Battery current sensor (Refer to 

EC-400, "Component Inspection"

.)

• Refrigerant pressure sensor (Refer to 

HAC-84, "Diagnosis Procedure"

.)

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace malfunctioning component.

6.

CHECK APP SENSOR

Refer to 

EC-444, "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-445, "Special Repair Requirement"

.

>> INSPECTION END

8.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-313, "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-36, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005236901

1.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

1.

Turn ignition switch OFF.

2.

Remove EVAP control system pressure sensor with its harness connector.
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 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?

ECM

Condition

[Applied vacuum kPa (kg/cm

2

, psi)]

Voltage (V)

Connector

+

–

Terminal

Terminal

M107

102

112

Not applied

1.8 - 4.8

-26.7 (-0.272, -3.87)

2.1 to 2.5 lower than above value

EC-314

< DTC/CIRCUIT DIAGNOSIS >

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P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

YES

>> INSPECTION END

NO

>> Replace EVAP control system pressure sensor

P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR

EC-315

< DTC/CIRCUIT DIAGNOSIS >

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P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR

Description

INFOID:0000000005236902

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:0000000005236903

DTC DETECTION LOGIC

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.

TESTING CONDITION:
Always perform test at a temperature of 5

°

C (41

°

F) or more.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT-III

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON.

PBIB3370E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0452

EVAP control system 
pressure sensor low in-
put

An excessively low voltage from the sensor is 
sent to ECM.

• Harness or connectors

(EVAP control system pressure sensor 
circuit is open or shorted.)
[Crankshaft position (CKP) sensor circuit 
is shorted.]
[Camshaft position (CMP) sensor (bank 
2) circuit is shorted.]
[Exhaust valve timing (EVT) control posi-
tion sensor (bank 2) circuit is shorted.]
(Battery current sensor circuit is shorted.)
[Accelerator pedal (APP) sensor 2 circuit 
is shorted.]
(Refrigerant pressure sensor circuit is 
shorted.)

• EVAP control system pressure sensor
• CKP sensor
• CMP sensor (bank 2)
• EVT control position sensor (bank 2)
• Battery current sensor
• APP sensor
• Refrigerant pressure sensor

EC-316

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

Turn ignition switch ON.

6.

Select “DATA MONITOR” mode with CONSULT-III.

7.

Check that “FUEL T/TMP SE” is more than 0

°

C (32

°

F).

8.

Start engine and wait at least 20 seconds.

9.

Check 1st trip DTC.

With GST

1.

Start engine and warm it up to normal operating temperature.

2.

Set voltmeter probes to ECM harness connector terminals under the following conditions.

3.

Check that the voltage is less than 4.2 V.

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

Turn ignition switch ON.

6.

Turn ignition switch OFF and wait at least 10 seconds.

7.

Start engine and wait at least 20 seconds.

8.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-316, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005236904

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-39, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK CONNECTOR

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-I

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 10.

NO

>> GO TO 4.

ECM

Connector

+

–

Terminal

Terminal

M107

106

(Fuel tank temperature sensor signal)

128

Water should not exist.

EVAP control system 

pressure sensor

Ground

Voltage (V)

Connector

Terminal

B252

3

Ground

Approx. 5