Infiniti FX35 / FX45. Manual - part 549

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

EC-957

< SERVICE INFORMATION >

[VK45DE]

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DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

Component Description

INFOID:0000000001326796

The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.

CONSULT-III Reference Value in Data Monitor Mode

INFOID:0000000001326797

Specification data are reference values.

On Board Diagnosis Logic

INFOID:0000000001326798

NOTE:
If DTC P0451 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to

EC-1009

.

DTC Confirmation Procedure

INFOID:0000000001326799

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

 WITH CONSULT-III

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.

PBIB1522E

PBIB1207E

MONITOR ITEM

CONDITION

SPECIFICATION

EVAP SYS PRES

• Ignition switch: ON

Approx. 1.8 - 4.8V

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0451
0451

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

EC-958

< SERVICE INFORMATION >

[VK45DE]

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

4.

If 1st trip DTC is detected, go to 

EC-958, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000001326800

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten three ground screws on the body.
Refer to 

EC-723, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK EVPA CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER

1.

Disconnect EVAP control system pressure sensor harness connector.

2.

Check sensor harness connector for water.

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace harness connector.

3.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-958, "Component Inspection"

.

OK or NG

OK

>> GO TO 4.

NG

>> Replace EVAP control system pressure sensor.

4.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-717

.

For Wiring Diagram, refer to 

EC-962

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326801

EVAP CONTROL SYSTEM PRESSURE SENSOR

1.

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

PBIB2195E

Water should not exist.

PBIB1522E

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

EC-959

< SERVICE INFORMATION >

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Always replace O-ring with a new one.

2.

Install a vacuum pump to EVAP control system pressure sensor.

3.

Turn ignition switch ON and check output voltage between ECM
terminal 32 and ground under the following conditions.

CAUTION:

• Always calibrate the vacuum pump gauge when using it.
• Do not apply below -93.3 kPa (- kg/cm

2

, -13.53 psi) or pres-

sure over 101.3 kPa (1.033 kg/cm

2

, 14.69 psi).

4.

If NG, replace EVAP control system pressure sensor.

Applied vacuum kPa

(kg/cm

2

, psi)

Voltage V

Not applied

1.8 - 4.8

-26.7 (-0.272, -3.87)

2.1 to 2.5V lower than above value

PBIB1173E

EC-960

< SERVICE INFORMATION >

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DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR

DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR

Component Description

INFOID:0000000001326802

The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.

CONSULT-III Reference Value in Data Monitor Mode

INFOID:0000000001326803

Specification data are reference values.

On Board Diagnosis Logic

INFOID:0000000001326804

NOTE:
If DTC P0452 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to

EC-1009

.

DTC Confirmation Procedure

INFOID:0000000001326805

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Always perform test at a temperature of 5

°

C (41

°

F) or more.

 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.

PBIB1522E

PBIB1207E

MONITOR ITEM

CONDITION

SPECIFICATION

EVAP SYS PRES

• Ignition switch: ON

Approx. 1.8 - 4.8V

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0452
0452

EVAP control system 
pressure sensor low in-
put

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

• Harness or connectors

(The sensor circuit is open or shorted.)

• EVAP control system pressure sensor