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Home >> Mitsubishi >> 2001 >> Eclipse RS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0455: EVAP System Large Leak Detected >> Diagnostic Procedure (2.4L)
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Diagnostic Procedure (2.4L)

NOTE: The following test procedure requires functions available on manufacturer's MUT-II scan tool. Generic scan tools may not have the capability to carry out test. An improperly tightened fuel cap can cause this code to set. Check for properly installed fuel cap and a good seal between the fuel cap and fuel filler neck.
  1. Disconnect hose "A" from intake manifold. See Figure . Connect hand vacuum pump to hose "A". Apply 12 in. Hg (40 kPa) or less of vacuum. If vacuum holds, go to step  3 . If vacuum leaks, go to next step.
  2. Using hand vacuum pump, check hose "A" for leaks. If leak exists, replace hose "A", then go to step  32 . If leak does not exist, replace purge solenoid, then go to step  32 .
  3. Disconnect hose "B" from purge solenoid. Turn ignition on. Using scan tool, select actuator test item No. 8 (purge solenoid) and turn on (open) purge solenoid. Vacuum should return to atmospheric pressure. If purge solenoid operates and vacuum returns to atmospheric pressure, go to step  5 . If purge solenoid operates and vacuum does not return to atmospheric pressure, go to next step. If purge solenoid does not operate, see DTC P0443: EVAPORATIVE EMISSION (EVAP) SYSTEM PURGE SOLENOID CIRCUIT MALFUNCTION  .
  4. Exit actuator test. Using hand vacuum pump, check hose "A" for clogging. If clogging exists, replace hose "A", then perform purge flow check. See PURGE CONTROL SYSTEM CHECK (PURGE FLOW CHECK) under FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If clogging does not exist, replace purge solenoid, then go to step  32 .
  5. Reconnect hoses "A" and "B". Remove vent valve module bracket mounting bolts. Disconnect hose "E" from ventilation solenoid. Connect hand vacuum pump to ventilation solenoid. See Figure . Apply vacuum to ventilation solenoid. Vacuum should leak. Using scan tool, select actuator test item No. 29 (ventilation solenoid) and turn on (close) ventilation solenoid. Apply vacuum to ventilation solenoid. Vacuum should hold. If ventilation solenoid performs as specified, go to next step. If ventilation solenoid operates, but vacuum leaks when ventilation solenoid is turned on (closed), replace ventilation solenoid, then go to step  32 . If ventilation solenoid operates, but vacuum does not leak when ventilation solenoid is turned off (opened), locate and repair clogging between ventilation solenoid and air intake, then go to step  32 . If ventilation solenoid does not operate, go to DTC P0446: EVAPORATIVE EMISSION (EVAP) SYSTEM VENT CONTROL MALFUNCTION  .
    NOTE: Before pressure testing, confirm Miller EVAP System Pressure Pump (6872A) is operating properly. Perform self-test procedures described in manufacturer's instructions.
  6. Exit actuator test. Plug end of hose "E" that was disconnected from ventilation solenoid. Connect EVAP system pressure pump to fuel filler neck. Pressure test system by performing I/M240 simulation test described in EVAP system pressure pump manufacturer's instructions located in lid of pump box. If leak is indicated, go to next step. If leak is not indicated, go to step  19 .
  7. Disconnect and plug hose "G" at EVAP canister side. See Figure . Repeat pressure test. If leak is indicated, go to step  11 . If leak is not indicated, go to next step.
  8. Using hand vacuum pump, check for leaks in hoses "B" and "C" and chamber. See Figure . If leak exists, replace appropriate hose or chamber, then go to step  32 . If leak does not exist, go to next step.
  9. Remove fuel tank. Using hand vacuum pump, check for leaks in hoses "D" through "F". See Figure . If problem exists, replace appropriate hose(s), install fuel tank, then go to step  32 . If problem does not exist, go to next step.
  10. Connect hand vacuum pump to EVAP canister port from which hose "E" was disconnected. Plug other 2 EVAP canister ports. Apply vacuum. If vacuum holds, install fuel tank, then go to step  32 . If vacuum does not hold, replace EVAP canister, install fuel tank, then go to step  32 .
  11. Remove fuel filler neck assembly. Using hand vacuum pump, check hoses "G", "J", "K", "L" and "M" for leaks. See Figure and Figure . If problem exists, replace appropriate hose(s), install fuel filler neck and go to step  32 . If problem does not exist, go to next step.
  12. Remove check valve "A". Blow on check valve "A" in both directions. Check valve "A" should leak air only in direction shown in illustration. See Figure . If check valve "A" passes air as indicated, go to next step. If check valve "A" does not pass air as indicated, replace check valve "A", install fuel filler neck and go to step  32 .
  13. Remove check valve "B". Blow on check valve "B" in both directions. Check valve "B" should pass more air in one direction than the other as shown in illustration. See Figure . If check valve "B" passes air as indicated, go to next step. If check valve "B" does not pass air as indicated, replace check valve "B", install fuel filler neck and go to step  32 .
  14. Disconnect hose "H" at liquid separator end and connect hand vacuum pump to hose "H". See Figure . Disconnect and plug hose "I" at fuel tank end. See Figure . Apply vacuum. If vacuum holds, go to next step. If vacuum does not hold, go to step  18 .
  15. Remove fuel tank. Using hand vacuum pump, check hose "N" for leaks. See Figure . If problem exists, replace hose "N", install fuel tank and fuel filler neck, then go to step  32 . If problem does not exist, go to next step.
  16. Visually check fuel tank for cracks and leaks. Connect EVAP system pressure tester to leveling valve port. See  32 . Securely plug all fuel tank openings. Using EVAP system pressure tester, apply pressure. Using soapy water, check each section of fuel tank for leaks. If leak exists, repair leak as necessary, install fuel tank and fuel filler neck, then go to step  32 . If leak does not exist, go to next step.
  17. Visually check fuel filler neck for cracks. If leak exists, replace fuel filler neck assembly, install fuel tank and go to step  32 . If leak does not exist, install fuel tank and fuel filler neck, then go to step  32 .
  18. Using hand vacuum pump, check hoses "H" and "I" and pipe between hoses "H" and "I" for leaks. See Figure . If leak exists, replace appropriate hose(s) or pipe, then go to step  32 . If leak does not exist, go to step  32 .
  19. Remove plug from hose "E". On EVAP system pressure pump, set pressure/hold valve to OPEN and set vent valve to CLOSED. Turn pump timer on. Air should pass through hose "E". If air passes through hose "E", go to step  23 . If air does not pass through hose "E", go to next step.
  20. Disconnect hose "G" at EVAP canister side. See Figure . On EVAP system pressure pump, set pressure/hold valve to OPEN and set vent valve to CLOSED. Turn pump timer on. Air should pass through hose "G". If air passes through hose "G", go to next step. If air does not pass through hose "G", go to step  27 .
  21. Remove fuel tank. Using hand vacuum pump, check hoses "E" and "F" for clogging. See Figure . If problem exists, replace appropriate hose(s), install fuel tank, then go to step  34 . If problem does not exist, go to next step.
  22. Connect hand vacuum pump to EVAP canister port from which hose "E" was disconnected. Plug other 2 EVAP canister ports. Apply vacuum. Unplug ports in turn. Each port should leak vacuum. If vacuum holds when either port is unplugged, replace EVAP canister, install fuel tank, then go to step  34 . If vacuum leaks, install fuel tank and go to step  32 .
  23. Disconnect hose "D" at floor pipe side. See Figure . Connect hand vacuum pump to floor pipe. Apply 12 in. Hg (40 kPa) or less of vacuum. Using scan tool, select actuator test item No. 8 (purge solenoid) and turn on (open) purge solenoid valve. If vacuum leaks, go to step  26 . If vacuum does not leak, go to next step.
  24. Using hand vacuum pump, check hoses "B" and "C" for clogging. See Figure . If problem exists, repair appropriate hose(s), then perform purge flow check. See PURGE CONTROL SYSTEM CHECK (PURGE FLOW CHECK) under FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If problem does not exist, go to next step.
  25. Remove chamber. See Figure . Using hand vacuum pump, check chamber for clogging. If problem exists, replace chamber, then go to step  34 . If problem does not exist, go to step  32 .
  26. Remove fuel tank. Using hand vacuum pump, check hose "D" for clogging and EVAP canister for clogging. See Figure . Replace hose "D" or EVAP canister as necessary, install fuel tank, then go to step  34 .
  27. Remove fuel filler neck assembly. Using hand vacuum pump, check hoses "G" and "J" through "M" for clogging. See Figure and Figure . If problem exists, replace appropriate hose(s), install fuel tank and fuel filler neck, then go to step  34 . If problem does not exist, go to next step.
  28. Remove check valve "A". Blow on check valve "A" in both directions. Check valve "A" should leak air only in direction shown in illustration. See Figure . If check valve "A" passes air as indicated, go to next step. If check valve "A" does not pass air as indicated, replace check valve "A", install fuel tank and fuel filler neck and go to step  34 .
  29. Remove check valve "B". Blow on check valve "B" in both directions. Check valve "B" should pass more air in one direction than the other as shown in illustration. See Figure . If check valve "B" passes air as indicated, go to next step. If check valve "B" does not pass air as indicated, replace check valve "B", instal fuel tank and fuel filler neck, then go to step  34 .
  30. Using hand vacuum pump, check hoses "H" and "I" and pipe between hoses "H" and "I" for clogging. See Figure . If problem exists, replace appropriate hose or pipe, install fuel tank and fuel filler neck, then go to step  34 . If problem does not exist, go to next step.
  31. Remove fuel tank, if not previously removed. Using hand vacuum pump, check hose "N" for clogging. See Figure . If problem exists, replace hose "N", install fuel tank and fuel filler neck as necessary, then go to step  34 . If problem does not exist, install fuel tank and fuel filler neck as necessary, then go to next step.
  32. Ensure fuel cap is tightened 3 clicks. Turn ignition on. Using scan tool, clear DTCs. Start engine and let idle. Start EVAP system leak monitor test using MUT-II scan tool. Select SYSTEM TEST and press YES key. Select EVAP LEAK MON and press YES key. During monitor, keep accelerator pedal in idling position. Item IN PROGRESS is displayed during monitor. IN PROGRESS will change from NO to YES by keeping engine speed and load within defined range. Go next step.
    NOTE: If engine speed does not reach 2000 RPM during monitor, adjustment of fixed Speed Adjusting Screw (SAS) may be needed. See FIXED SPEED ADJUSTING SCREW under IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS article.
  33. If EVAP LEAK MON. COMPLETED. TEST PASSED is displayed, EVAP system currently is working properly. Code was probably set by improperly installed fuel cap. If EVAP LEAK MON. COMPLETED. TEST FAILED & DTCS SET is displayed, go to step  1 . If EVAP LEAK MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed, turn ignition off, and repeat monitor. Go to step  32 .
  34. Test drive vehicle following OBD-II drive cycle EVAP system leak monitor pattern. See EVAP SYSTEM LEAK MONITOR  under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0455 is output, retry diagnostic procedure. If DTC P0455 is not output, inspection is complete.
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