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Home >> Suzuki >> 2009 >> Equator Base, 4D Pickup >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (VQ40DE) - (2 Of 5) >> DTC P0456: EVAP Control System >> Diagnosis Procedure
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Diagnosis Procedure

DIAGNOSIS PROCEDURE

Step Action YES NO
1  CHECK FUEL FILLER CAP DESIGN 
  1. Turn ignition switch OFF.
  2. Check for genuine fuel filler cap design.

OK or NG 		 GO TO 2. Replace with genuine fuel filler cap.
2  CHECK FUEL FILLER CAP INSTALLATION 
Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG 		 GO TO 3.
  1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
  2. Retighten until ratcheting sound is heard.
3  CHECK FUEL FILLER CAP FUNCTION 
Check for air releasing sound while opening the fuel filler cap.
OK or NG 		 GO TO 5. GO TO 4.
4  CHECK FUEL TANK VACUUM RELIEF VALVE 
Refer to [P0442 EVAP CONTROL SYSTEM ].
OK or NG 		 GO TO 5. Replace fuel filler cap with a genuine one.
5  INSTALL THE PRESSURE PUMP 
To locate the EVAP leak, install EVAP service port adapter and pressure pump to EVAP service port securely. For the location of EVAP service port, refer to [EVAPORATIVE EMISSION SYSTEM: DESCRIPTION ]		 GO TO 6. GO TO 7.
6  CHECK FOR EVAP LEAK 
With SDT 
  1. Turn ignition switch ON.
  2. Select "EVAP SYSTEM CLOSE" of "Utility" mode with SDT.
  3. Touch "START" and apply pressure into the EVAP line until the pressure indicator reaches the middle of the bar graph.
    CAUTION:
    • Never use compressed air or a high pressure pump.
    • Never exceed 4.12 kPa (0.042 kg/cm2 , 0.6 psi) of pressure in the system.
  4. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details.
G06441512Courtesy of SUZUKI OF AMERICA CORP.

Refer to [EVAPORATIVE EMISSION SYSTEM: DESCRIPTION ]


OK or NG 		 GO TO 8. Repair or replace.
7  CHECK FOR EVAP LEAK 
Without SDT 
  1. Turn ignition switch OFF.
  2. Apply 12 volts DC to EVAP canister vent control valve (1). The valve will close. (Continue to apply 12 volts until the end of test.)
G06441513G06441514Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.
  • EVAP control system pressure sensor (2)
  • Drain filter (3)
  • EVAP canister (4)
  • <=: Vehicle front

  1. 3. Pressurize the EVAP line using pressure pump with 1.38 to 2.76 kPa (0.014 to 0.028 kg/cm2 , 0.2 to 0.4 psi), then remove pump and EVAP service port adapter.
    CAUTION:
    • Never use compressed air or a high pressure pump.
    • Never exceed 4.12 kPa (0.042 kg/cm2 , 0.6 psi) of pressure in the system.
  2. 4. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details. Refer to [EVAPORATIVE EMISSION SYSTEM: DESCRIPTION ]
G06441513G06441514Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

OK or NG 		 GO TO 8. Repair or replace.
8  CHECK EVAP CANISTER VENT CONTROL VALVE 
Check the following.

OK or NG 		 GO TO 9. Repair or replace EVAP canister vent control valve and O-ring.
9  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. Does water drain from the EVAP canister?
G06441515Courtesy of SUZUKI OF AMERICA CORP.

Yes or No 		 GO TO 10. GO TO 12.
10  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 2.0 kg (4.4 lb). 
OK or NG 		 GO TO 12. GO TO 13.
11  DETECT MALFUNCTIONING PART 
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.  
12  CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION 
With SDT 
  1. Disconnect vacuum hose connected to EVAP service purge volume control solenoid valve from EVAP canister purge volume control solenoid valve.
  2. Start engine.
  3. Perform "PURG VOL CONT/V" in "Active test" mode.
  4. Touch "Qu" on SDT screen to increase "PURG VOL CONT/V" opening to 100%.
  5. Check vacuum hose for vacuum when revving engine up to 2, 000 RPM.

OK or NG 		 GO TO 16. GO TO 14.
13  CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION 
Without SDT 
  1. Start engine and warm it up to normal operating temperature.
  2. Stop engine.
  3. Disconnect vacuum hose connected to EVAP service purge volume control solenoid valve from EVAP canister purge volume control solenoid valve.
  4. Start engine and let it idle for at least 80 seconds.
  5. Check vacuum hose for vacuum when revving engine up to 2, 000 RPM.

    Vacuum should exist. 


OK or NG 		 GO TO 15. GO TO 14.
14  CHECK VACUUM HOSE 
Check vacuum hoses for clogging or disconnection. Refer to [EVAPORATIVE EMISSION SYSTEM: DESCRIPTION ]
OK or NG 		 GO TO 15. Repair or reconnect the hose.
15  CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE 
Refer to [P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE ].
OK or NG 		 GO TO 16. Replace EVAP canister purge volume control solenoid valve.
16  CHECK FUEL TANK TEMPERATURE SENSOR 
Refer to [P0181 FTT SENSOR ].
OK or NG 		 GO TO 17. Replace fuel level sensor unit.
17  CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 
Refer to [P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR ].
OK or NG 		 GO TO 18. Replace EVAP control system pressure sensor.
18  CHECK EVAP PURGE LINE 
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks or improper connection. Refer to [EVAPORATIVE EMISSION SYSTEM: DESCRIPTION ]
OK or NG 		 GO TO 19. Repair or reconnect the hose.
19  CLEAN EVAP PURGE LINE 
Clean EVAP purge line (pipe and rubber tube) using air blower.		 GO TO 20.  
20  CHECK EVAP/ORVR LINE 
Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kinks, looseness and improper connection. For location, refer to [ON BOARD REFUELING VAPOR RECOVERY (ORVR) CIRCUIT CHECK ].
OK or NG 		 GO TO 21. Repair or replace hoses and tubes.
21  CHECK RECIRCULATION LINE 
Check recirculation line between filler neck tube and fuel tank for clogging, kinks, cracks, looseness and improper connection.
OK or NG 		 GO TO 22. Repair or replace hose, tube or filler neck tube.
22  CHECK REFUELING EVAP VAPOR CUT VALVE 
Refer to [ON BOARD REFUELING VAPOR RECOVERY (ORVR) CIRCUIT CHECK ].
OK or NG 		 GO TO 23. Replace refueling EVAP vapor cut valve with fuel tank.
23  CHECK FUEL LEVEL SENSOR 
Refer to [FUEL LEVEL SENSOR SIGNAL CIRCUIT CHECK ]
OK or NG 		 GO TO 24. Replace fuel level sensor unit.
24  CHECK INTERMITTENT INCIDENT 
Refer to [SERVICE INFORMATION FOR ELECTRICAL INCIDENT: INTERMITTENT INCIDENT ]		 INSPECTION END   
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