LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2004 >> Q45 >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P1456: EVAP Control System >> Diagnostic Procedure >> 7. Check For EVAP Leak
April 5, 2026: LEMON Manuals is launched! Read the announcement.

7. Check For EVAP Leak

Without CONSULT-II 

  1. Turn ignition switch OFF.
  2. Apply 12 volts DC to EVAP canister vent control valve. The valve will close. (Continue to apply 12 volts until the end of test.)
  3. Apply 12 volts DC to vacuum cut valve bypass valve. The valve will open. (Continue to apply 12V until the end of test.)
  4. Pressurize the EVAP line using pressure pump with 1.3 to 2.7 kPa (10 to 20 mmHg, 0.39 to 0.79 inHg), then remove pump and EVAP service port adapter.
    NOTE:
    • Never use compressed air or a high pressure pump.
    • Do not exceed 4.12 kPa (0.042 kg/cm2 , 0.6 psi) of pressure in the system.
  5. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details. Refer to EVAPORATIVE EMISSION LINE DIAGRAM  .

OK or NG 

OK: GO TO 8.

NG: Repair or replace.