Infiniti QX56 (Z62). Manual - part 589

EC-334

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 3.

3.

CHECK SENSOR POWER SUPPLY CIRCUIT

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

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 (Refer to 

EC-301, "Component Inspection (Crankshaft Position Sensor)"

.)

• Camshaft position sensor (bank 1) (Refer to 

EC-306, "Component Inspection (Camshaft Position Sensor)"

.)

• Battery current sensor (Refer to 

EC-427, "Component Inspection (Battery Current Sensor)"

.)

• Refrigerant pressure sensor (Refer to 

EC-520, "Component Function Check"

.)

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace malfunctioning component.

5.

CHECK APP SENSOR

Refer to

EC-470, "Component Inspection (Accelerator Pedal Position Sensor)"

.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> GO TO 6.

6.

REPLACE ACCELERATOR PEDAL ASSEMBLY

Replace accelerator pedal assembly.
Refer to 

ACC-3, "MODELS WITHOUT DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation"

(Without distance control assist system)
Refer to 

ACC-4, "MODELS WITH DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation"

 (With

distance control assist system).

>> INSPECTION END

7.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-335, "Component Inspection (EVAP Control System Pressure Sensor)"

.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Replace EVAP control system pressure sensor.

8.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

ECM

Sensor

Connector

Terminal

Name

Connector

Terminal

F110

76

Crankshaft position sensor

F74

1

77

Camshaft position sensor (bank 1)

F84

1

E80

133

EVAP control system pressure sen-
sor

C17

3

Battery current sensor

E63

2

Refrigerant pressure sensor

E77

1

131

APP sensor 2 (Without ICC)

E110

1

APP sensor 2 (with ICC)

E67

9

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

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>> INSPECTION END

Component Inspection (EVAP Control System Pressure Sensor)

INFOID:0000000006288318

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?

YES

>> INSPECTION END

NO

>> Replace EVAP control system pressure sensor.

ECM

Condition

[Applied vacuum kPa (kg/cm

2

, psi)]

Voltage (V)

Connector

+

–

Terminal

Terminal

E80

143

150

Not applied

1.8 - 4.8

-26.7 (-0.272, -3.87)

2.1 to 2.5 lower than above value

EC-336

< DTC/CIRCUIT DIAGNOSIS >

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P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR

P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR

DTC Logic

INFOID:0000000006288319

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

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.

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.

DTC No.

Trouble diagnosis name

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0452

EVAP SYS PRES SEN
(EVAP control system pres-
sure sensor low input)

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

• (EVAP control system pressure sensor circuit is short-

ed.)
Harness or connectors
(Battery current sensor circuit is open or shorted.)
(Accelerator pedal position sensor 2 circuit is shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Crankshaft position sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)

• EVAP control system pressure sensor
• Battery current sensor
• Accelerator pedal position sensor
• Camshaft position sensor (bank 1)
• Crankshaft position sensor
• Refrigerant pressure sensor

ECM

Connector

+

–

Terminal

Terminal

E80

134

(Fuel tank temperature sensor signal)

175

P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR

EC-337

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8.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-337, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006288320

1.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR

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 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 9.

NO

>> GO TO 3.

3.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT-II

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check the continuity between EVAP control system pressure sensor harness connector and ECM har-
ness connector.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.
• Harness for open between ECM and EVAP control system pressure sensor
• Loose or poor connection for each connector and harness

>> Repair open circuit.

5.

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

C17

3

Ground

Approx. 5

EVAP control system 

pressure sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

C17

3

E80

133

Existed

ECM

Sensor

Connector

Terminal

Name

Connector

Terminal

F110

76

Crankshaft position sensor

F74

1

77

Camshaft position sensor (bank 1)

F84

1