Nissan Versa

 Sedan Service Manual

Engine » Engine control system (EC) » P0451 EVAP control system pressure sensor
Diagnosis Procedure

1.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER

1. Turn ignition switch OFF.
2. Disconnect EVAP control system pressure sensor harness connector.
3. Check sensor harness connector for water.

Water should not exist.

Is the inspection result normal?

YES >> GO TO 2.

 NO >> Repair or replace harness connector.

2.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY

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 6.

NO >> GO TO 3.

3.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between EVAP control system pressure sensor harness connector and ECM harness connector. 

    4.   Also check harness for short to ground and to power.

Is the inspection result normal?

YES >> GO TO 4.

NO >> Repair or replace errordetected parts

4.CHECK SENSOR POWER SUPPLY CIRCUIT

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

*: With A/C models

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.

• Battery current sensor (Refer to EC, "Component Inspection").
• CKP sensor (POS) (Refer to EC, "Component Inspection").
• Refrigerant pressure sensor (Refer to EC, "Component Function Check").
• Accelerator pedal position sensor (Refer to EC, "Component Inspection").

Is the inspection result normal?

YES >> Check intermittent incident. Refer to GI, "Intermittent Incident".

NO >> Replace malfunctioning component.

6.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR GROUND CIRCUIT

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between EVAP control system pressure sensor harness connector and ECM harness connector 
4. Also check harness for short to power.

Is the inspection result normal?

YES >> GO TO 7.

NO >> Repair or replace errordetected parts.

7.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR SIGNAL CIRCUIT

    1.   Check the continuity between EVAP control system pressure sensor harness connector and ECM harness connector. 

    2.   Also check harness for short to ground and to power.

Is the inspection result normal?

YES >> GO TO 8.

NO >> Repair or replace errordetected parts.

8.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Check the EVAP control system pressure sensor. Refer to EC, "Component Inspection".

Is the inspection result normal?

YES >> Check intermittent incident. Refer to GI, "Intermittent Incident".

NO >> Replace EVAP control system pressure sensor. Refer to FL, "Removal and Installation".

DTC Logic

Diagnosis Procedure

Component Inspection