Diagnostic Procedure

Do you have CONSULT-II?

Yes or No

1. Yes: GO TO 2.
2. No: GO TO  3 .

With CONSULT-II 

1. Turn ignition switch OFF.
2. Remove vacuum cut valve and vacuum cut valve bypass valve as an assembly.
3. Apply vacuum to port A and check that there is no suction from port B.
4. Apply vacuum to port B and check that there is suction from port A.
5. Blow air in port B and check that there is a resistance to flow out of port A.
6. Turn ignition switch ON.
7. Select VC/V BYPASS/V in ACTIVE TEST mode with CONSULT-II and touch ON.
8. Blow air in port A and check that air flows freely out of port B.
9. Blow air in port B and check that air flows freely out of port A.
   Fig 1: Checking Vacuum Cut Valve Bypass Valve Operation With CONSULT-II

   Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

1. OK: GO TO  4 .
2. NG: GO TO  5 .

Without CONSULT-II 

1. Turn ignition switch OFF.
2. Remove vacuum cut valve and vacuum cut valve bypass valve as an assembly.
3. Apply vacuum to port A and check that there is no suction from port B.
4. Apply vacuum to port B and check that there is suction from port A.
5. Blow air in port B and check that there is a resistance to flow out of port A.
6. Disconnect vacuum cut valve bypass valve harness connector.
7. Supply battery voltage to the terminal.
8. Blow air in port A and check that air flows freely out of port B.
9. Blow air in port B and check that air flows freely out of port A.
   Fig 2: Checking Vacuum Cut Valve Bypass Valve Operation Without CONSULT-II

   Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

1. OK: GO TO 4.
2. NG: GO TO  7 .

Check EVAP purge line between EVAP canister and fuel tank for clogging or disconnection.

OK or NG 

1. OK: GO TO 5.
2. NG: Repair it.

Check EVAP purge port of fuel tank for clogging.

OK or NG 

1. OK: GO TO 6.
2. NG: clean EVAP purge port.

1. Pinch the fresh air hose.
2. Blow air into port A  and check that it flows freely out of port B. 
   Fig 3: Identifying EVAP Canister Ports

   Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

   1. OK: GO TO  12 .
   2. NG: Replace EVAP canister.

Check bypass hoses for clogging.

OK or NG 

1. OK: GO TO 8.
2. NG: Repair or replace hoses.

With CONSULT-II 

1. Perform VC/V BYPASS/V in ACTIVE TEST mode.
2. Check air passage continuity and operation delay time under the following conditions. See Figure .

Without CONSULT-II 

Check air passage continuity and operation delay time under the following conditions. See Figure .

OK or NG 

1. OK: GO TO 9.
2. NG: Replace vacuum cut valve bypass valve.

Check vacuum cut valve as follows:

Fig 4: Checking Vacuum Cut Valve

Courtesy of NISSAN MOTOR CO., U.S.A.

1. Plug port C  and D  with fingers.
2. Apply vacuum to port A  and check that there is no suction from port B. 
3. Apply vacuum to port B  and check that there is suction from port A. 
4. Blow air in port B  and check that there is a resistance to flow out of portA. 
5. Open port C  and D. 
6. Blow air in port A  check that air flows freely out of port C. 
7. Blow air in port B  check that air flows freely out of port D. 

OK or NG 

1. OK: GO TO 10.
2. NG: Replace vacuum cut valve.

1. Turn ignition switch OFF.
2. Check disconnection or improper connection of hose connected to EVAP control system pressure sensor.

OK or NG 

1. OK: GO TO 11.
2. NG: Repair or replace

1. Disconnect EVAP control system pressure sensor harness connector.
   Fig 5: Checking EVAP Control System Pressure Sensor Connector

   Courtesy of NISSAN MOTOR CO., U.S.A.
2. Check connectors for water.

Water should not exist. 

OK or NG 

1. OK: GO TO 12.
2. NG: Replace EVAP control system pressure sensor.

1. Remove EVAP control system pressure sensor with its harness connector connected. See Figure .
   CAUTION: Never apply force to the air hole protector of the sensor if equipped.
2. Remove hose from EVAP control system pressure sensor.
3. Turn ignition switch ON
4. Use pump to apply vacuum and pressure to EVAP control system pressure sensor as shown in Figure .
   CAUTION:

   • Always calibrate the vacuum pump gauge when using it.
   • Do not apply below -20 kPa (-150 mmHg, -5.91 inHg) or over 20 kPa (150 mmHg, 5.91 inHg) of pressure.
5. Check input voltage between ECM terminal 84 and ground. See Figure and Figure .

OK or NG 

1. OK: GO TO 13.
2. NG: Replace EVAP control system pressure sensor.

1. Disconnect rubber tube connected to EVAP canister vent control valve.
2. Check the rubber tube for clogging.

OK or NG 

1. OK: GO TO 14.
2. NG: Clean the rubber tube using an air blower.

1. Remove EVAP canister vent control valve from EVAP canister.
2. Check portion B  of EVAP canister vent control valve for being rusted. See Figure .

OK or NG 

1. OK: GO TO 15.
2. NG: Replace EVAP canister vent control valve.

With CONSULT-II 

1. Reconnect harness disconnected connectors.
2. Turn ignition switch ON.
3. Perform VENT CONTROL/V in ACTIVE TEST mode.
4. Check air passage continuity and operation delay time. See Figure .

Without CONSULT-II 

Check air passage continuity and operation delay time under the following conditions. See Figure .

Make sure new O-ring is installed properly. 

OK or NG 

1. OK: GO TO  17 17.
2. NG: GO TO 16.

1. Clean the air passage (Portion A  to B  ) of EVAP canister vent control valve using an air blower.
2. Perform the Test No.  15 again.

OK or NG 

1. OK: GO TO 17.
2. NG: Replace EVAP canister vent control valve.

Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

1. : INSPECTION END