Nissan Sentra B18 (2020-2025) Service Manual: P0448 Evap Canister Vent Control Valve

Dtc Description

DTC DETECTION LOGIC

POSSIBLE CAUSE

• EVAP canister vent control valve

• EVAP control system pressure sensor and the circuit

• Blocked rubber tube to EVAP canister vent control valve

• EVAP canister is saturated with water

FAIL-SAFE

Not applicable

Confirmation Procedure

1. PRECONDITIONING

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

   >>

   GO TO 2.

2. PERFORM DTC CONFIRMATION PROCEDURE

   With CONSULT

   1. Turn ignition switch ON and wait at least 5 seconds.

   2. Turn ignition switch OFF and wait at least 10 seconds.

   3. Turn ignition switch ON and select “DATA MONITOR” mode of “ENGINE” using CONSULT.

   4. Start the engine and let it idle for at least 1 minute.

   5. Repeat next procedures three times.

      1. Increase the engine speed up to 3,000 to 3,500 rpm and keep it for 2 minutes and 50 seconds to 3 minutes.

         Never exceed 3 minutes.

      2. Fully released accelerator pedal and keep engine idle for about 5 seconds.

   6. Repeat next procedure 20 times.

      • Quickly increase the engine speed up to 4,000 to 4,500 rpm or more and keep it for 25 to 30 seconds.

      • 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” above.

   Is 1st trip DTC detected?

   YES >>

   Proceed to DTC Diagnosis Procedure.

   NO-1 >>

   To check malfunction symptom before repair: Refer to Intermittent Incident.

   NO-2 >>

   Confirmation after repair: INSPECTION END

Dtc Diagnosis Procedure

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

   Check the EVAP canister vent control valve. Refer to Component Inspection.

   Is the inspection result normal?

   YES >>

   GO TO 3.

   NO >>

   Replace EVAP canister vent control valve. Refer to Exploded View.

3. CHECK IF EVAP CANISTER IS 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.

      

   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 2.1 kg (4.6 lb).

   Is the inspection result normal?

   YES >>

   GO TO 6.

   NO >>

   GO TO 5.

5. DETECT MALFUNCTIONING PART

   Check the following.

   • EVAP canister for damage

   • EVAP hose between EVAP canister and Nissan Sentra vehicle frame for clogging or poor connection

   >>

   Repair hose or replace EVAP canister. Refer to Removal and Installation.

6. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR

   1. Disconnect EVAP control system pressure sensor harness connector.

   2. Check connectors for water.

      Water should not exist.

   Is the inspection result normal?

   YES >>

   GO TO 7.

   NO >>

   Replace EVAP control system pressure sensor. Refer to Exploded View.

7. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

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

   Is the inspection result normal?

   YES >>

   INSPECTION END

   NO >>

   Replace EVAP control system pressure sensor. Refer to Exploded View.

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