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Home › Infiniti › 2003 › I35 › Repair and Diagnosis › Engine Performance › System › Engine Controls - Self-Diagnostics › Diagnostic Tests › DTC P0455: EVAP Control System Very Large Leak › Diagnostic Procedure

Diagnostic Procedure

  1. Ensure fuel cap is original equipment. Attempt to turn fuel cap clockwise. If fuel cap was tightened properly, go to next step. If fuel cap was not tightened properly, clean fuel cap and filler neck with compressed air. Reinstall cap and retest system.
  2. While removing fuel cap, listen for air escaping from fuel tank. If air escaped from fuel tank, go to step  4 . If air did not escape from fuel tank, go to next step.
  3. Using a suitable hand vacuum/pressure pump with Fuel Filler Cap Adapter (MLR-8382), apply pressure and vacuum to fuel cap. Fuel cap vacuum relief valve should open when pressure reaches 2.22-2.90 psi (15.3-20.0 kPa) and when vacuum reaches .98-1.78 in. Hg (3.3-6.0 kPa). If operation is as specified, go to next step. If operation is not as specified, replace fuel cap.
  4. Check EVAP purge line (hose, rubber tube, fuel tank and EVAP canister) for cracks, improper connection or disconnection. Repair or replace as necessary. If okay, clean EVAP purge line using air blower. Check EVAP canister vent control valve, "O" ring and circuit. See appropriate DTC confirmation test. If not okay, repair or replace EVAP canister vent control valve and "O" ring or harness connector. If okay, go to next step.
  5. Connect EVAP Service Port Adapter (J41413-OBD) to EVAP service port. See Figure . Connect a suitable pressure pump to adapter. DO NOT use compressed air. If using CONSULT-II, go to next step. If using generic scan tool, go to step  7 .
  6. Turn ignition on. Select EVAP SYSTEM CLOSE of WORK SUPPORT mode with CONSULT-II. Press START. Observe pressure indicator on CONSULT-II. Apply pressure to EVAP system until pressure indicator reaches middle of bar graph. DO NOT exceed .6 psi (4.12 kPa) of pressure. Using Leak Detector (J41416), locate EVAP leak. See VACUUM DIAGRAMS article. If a leak is found, repair as necessary. If no leak is found, go to step  8 .
  7. Turn ignition off. Disconnect EVAP Canister Vent Control Valve (EVAP-CVCV) and vacuum cut valve by-pass valve harness connectors. Using jumper wires, apply battery voltage to EVAP-CVCV and vacuum cut valve by-pass valve terminals. See Figure . Apply .2-.4 psi (1.38-2.76 kPa) of pressure to EVAP service port. DO NOT exceed .6 psi (4.12 kPa) of pressure. Remove pressure pump from EVAP service port. Using Leak Detector (J41416), locate EVAP system leak. See VACUUM DIAGRAMS article. If a leak is found, repair as necessary. If no leak is found, go to step  9 .
  8. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port. Start engine. Perform PURG VOL CONT/V in ACTIVE TEST mode with CONSULT-II. Touch Qu CONSULT-II screen to increase PURG VOL CONT/V opening to 100 percent. Engine speed should vary according to valve opening. Check vacuum hose for vacuum when revving engine up to 2000 RPM. Vacuum should exist. If operation is as specified, go to step  12 . If operation is not as specified, go to step  10 .
  9. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect EVAP-CPVCSV hose from EVAP service port. Start engine and let it idle for at least 80 seconds. While quickly increasing engine speed to 2000 RPM, check for vacuum at EVAP-CPVCSV hose. If vacuum exists, go to step  11 . If vacuum does not exist, go to next step.
  10. Check EVAP system vacuum hoses for blockages or leaks. See VACUUM DIAGRAMS article. If problem is found, repair as necessary. If problem is not found, go to next step.
  11. Remove EVAP-CPVCSV. Using jumper wires, apply battery voltage between EVAP-CPVCSV terminals. See Figure . Check for airflow between ports "A" and "B". Air should flow. Remove jumper wires. Air should not flow. If operation is as specified, go to next step. If operation is not as specified, replace EVAP-CPVCSV.
  12. Remove fuel pump assembly. Access cover is located under rear seat. Measure resistance between fuel pump assembly connector terminals No. 4 and 5, with FTT sensor submerged in heated water. See Figure . Resistance should be within acceptable range shown in illustration. See Figure . If resistance is as specified, go to next step. If resistance is not as specified, replace FTT sensor.
    13. CAUTION: DO NOT apply more than 5.91 in. Hg (20 kPa) of vacuum to EVAP-CSPS. Replace EVAP-CSPS if it has been dropped from a height of more than 20" (508 mm) onto a hard surface such as concrete.
    CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  13. Remove EVAP-CSPS with its harness connector connected. See Figure . Turn ignition on. Using a hand vacuum pump, apply 2.76 in. Hg (9.3 kPa) of vacuum to EVAP-CSPS. Measure voltage between ground and ECM terminal No. 60 (White wire) by backprobing. See Figure and Figure . Voltage should be .4-.6 volt. Disconnect vacuum pump. Voltage should be 3.0-3.6 volts. If voltage is as specified, go to next step. If voltage is not as specified, replace EVAP-CSPS.
  14. Check refueling EVAP vapor line between EVAP canister and fuel tank for clogging, kink, looseness or improper connection. See VACUUM DIAGRAMS article. If problem is found, repair or replace hoses or tubes as necessary. If problem is not found, go to next step.
  15. Check signal line and recirculation line between filler neck and fuel tank for clogging, kink, cracks, looseness and improper connection. If problem is found, repair or replace hoses, tubes or filler neck as necessary. If problem is not found, go to next step.
  16. Check refueling control valve. See FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If refueling control valve is okay, go to next step. If refueling control valve is not okay, replace refueling control valve with fuel tank.
  17. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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