Infiniti G37 Coupe. Manual - part 530

P0448 EVAP CANISTER VENT CONTROL VALVE

EC-301

< COMPONENT DIAGNOSIS >

[VQ37VHR]

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Fully released accelerator pedal and keep engine idle for at least 35 seconds.

7.

Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?

YES

>> Go to 

EC-301, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001734122

1.

CHECK RUBBER TUBE

1.

Turn ignition switch OFF.

2.

Disconnect rubber tube connected to EVAP canister vent control valve.

3.

Check the rubber tube for clogging.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Clean rubber tube using an air blower.

2.

CHECK EVAP CANISTER VENT CONTROL VALVE

Refer to 

EC-302, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Replace EVAP canister vent control valve.

3.

CHECK IF EVAP CANISTER SATURATED WITH WATER

1.

Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.

2.

Check if water will drain from the EVAP canister (1).

Does water drain from EVAP canister?

YES

>> GO TO 4.

NO

>> GO TO 6.

4.

CHECK EVAP CANISTER

Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.2 kg (4.9 lb).

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

PBIB0972E

2

: EVAP canister vent control valve

PBIB2731E

EC-302

< COMPONENT DIAGNOSIS >

[VQ37VHR]

P0448 EVAP CANISTER VENT CONTROL VALVE

Check the following.
• EVAP canister for damage
• EVAP hose between EVAP canister and vehicle frame for clogging or poor connection

>> Repair hose or replace EVAP canister.

6.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR

1.

Disconnect EVAP control system pressure sensor harness connector.

2.

Check connectors for water.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Replace EVAP control system pressure sensor.

7.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-306, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Replace EVAP control system pressure sensor.

8.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-38, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000001910882

1.

CHECK EVAP CANISTER VENT CONTROL VALVE-I

1.

Turn ignition switch OFF.

2.

Remove EVAP canister vent control valve from EVAP canister.

3.

Check portion (A) of EVAP canister vent control valve for being
rusted.

Is it rusted?

YES

>> Replace EVAP canister vent control valve

NO

>> GO TO 2.

2.

CHECK EVAP CANISTER VENT CONTROL VALVE-II

With CONSULT-III

1.

Reconnect harness connectors disconnected.

2.

Turn ignition switch ON.

3.

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

Water should not exist.

JMBIA0168ZZ

P0448 EVAP CANISTER VENT CONTROL VALVE

EC-303

< COMPONENT DIAGNOSIS >

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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

1.

Disconnect EVAP canister vent control valve harness connector.

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

>> GO TO 3.

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

>> Replace EVAP canister vent control valve

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

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-304

< COMPONENT DIAGNOSIS >

[VQ37VHR]

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

Description

INFOID:0000000001734124

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:0000000001734125

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing 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.

>> 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-304, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001734126

1.

CHECK GROUND CONNECTION

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.)
[CKP sensor (POS) circuit is shorted.]
(APP sensor 2 circuit is shorted.)
(Refrigerant pressure sensor circuit is 
shorted.)
(Brake booster pressure sensor circuit is 
shorted)

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