Diagnostic Procedure (2.4L)

1. Ensure transaxle is in Park (A/T) or Neutral (M/T) and fuel cap is securely tightened. Start engine and let idle. Clear DTCs. Using MUT-II scan tool, start EVAP system leak monitor test. Select SYSTEM TEST and press YES key. Select EVAP LEAK MON and press YES key. During monitor, keep accelerator pedal in idling position. Go to next step.
   NOTE: Monitor will automatically increase engine speed. 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.
2. Keep engine speed and engine load within specified range. When monitor starts, IN PROGRESS item on scan tool will change from NO to YES. 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 next step. If EVAP LEAK MON. DISCONTINUED is displayed, turn ignition off and start monitor over. Go to step  1 .
3. Confirm Miller EVAP System Pressure Pump (6872A) is operating properly. Perform self-test as described by manufacturer. Turn ignition off. Remove vent valve module bracket mounting bolts to access hose "E". Disconnect hose "E" from ventilation solenoid and plug disconnected end. See Fig 2 and Fig 3 . Connect EVAP system pressure pump to fuel filler neck. Perform I/M240 simulation test described in EVAP system pressure pump manufacturer's instructions located in lid of pump box. If no leak is indicated, go to next step. If leak is indicated, go to step  5 .
4. Connect hand vacuum pump to ventilation solenoid port from which hose "E" was disconnected. Turn ignition on. Using scan tool, select actuator test item No. 29 (ventilation solenoid) and turn ventilation solenoid on (closed). Using hand vacuum pump, apply vacuum. Vacuum should hold. Turn ventilation solenoid off (opened). Vacuum should return to atmospheric pressure. If ventilation solenoid holds and releases vacuum as specified, repeat step  1 . If ventilation solenoid operates but does not hold vacuum, replace ventilation solenoid, then repeat step  1 . If ventilation solenoid does not operate, check ventilation solenoid circuit. See DTC P0446: EVAPORATIVE EMISSION (EVAP) SYSTEM VENT CONTROL MALFUNCTION  .
5. Disconnect hose "G" from EVAP canister side and plug disconnected end. See Fig 4 . Using EVAP system pressure pump, repeat pressure test. If leak exists, go to step  10 . If leak does not exist, go to next step.
6. Remove plug and reconnect EVAP canister side of hose "G". Disconnect hose "B" from purge solenoid and plug disconnected end. See Fig 5 . Using EVAP system pressure pump, repeat pressure test. If leak exists, go to next step. If leak does not exist, replace purge valve, then go to step  1 .
7. Remove battery and air intake hose. Using hand vacuum pump, check hoses "B" and "C" for leaks. Check chamber between hoses "B" and "C" for leak. See Fig 6 . If leak exists, replace appropriate hose or chamber, then go to step  1 . If leak does not exist, go to next step.
8. Remove fuel tank. Using hand vacuum pump, check hoses "D" through "F" for leaks. See Fig 7 . If leak exists, replace appropriate hose, install fuel tank and go to step  1 . If leak does not exist, go to next step.
9. Connect hand vacuum pump to EVAP canister port from which hose "E" was removed. See Fig 7 . Plug other 2 EVAP canister ports. Apply vacuum to EVAP canister. If vacuum holds, go to step  1 . If vacuum does not hold, replace EVAP canister, install fuel tank and go to step  1 .
10. Remove fuel filler neck assembly. Using hand vacuum pump, check hoses "G" and "J" through "M" for leaks. See Fig 8 and Fig 9 . If leak exists, replace appropriate hose, install fuel tank filler neck and go to step  1 . If leak does not exist, go to next step.
11. 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 Fig 10 . 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  1 .
12. 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 Fig 11 . 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  1 .
13. Disconnect hose "H" from liquid separator and connect hand vacuum pump to hose "H". See Fig 12 . Disconnect hose "I" from fuel tank and plug hose end. See Fig 13 . Using hand vacuum pump, apply vacuum and check for leaks in hoses "H" and "I" and pipe between hoses "H" and "I". If leak exists, go to step  17 . If leak does not exist, go to next step.
14. Remove fuel tank. Using hand vacuum pump, check hose "N" and pipe between hoses "N" and "M" for leaks. See Fig 14 . If leak exists, replace hose or line, install fuel tank and fuel filler neck, then go to step  1 . If leak does not exist, go to next step.
15. Visually check fuel tank for cracks and leaks. Connect EVAP system pressure pump to leveling valve port. See Fig 14 . Plug all openings on fuel tank. Using EVAP system pressure pump, pressurize fuel tank. Check for leaks by applying soap to each section of fuel tank. If leak exists, repair leak, install fuel tank and fuel filler neck, then go to step  1 . If leak does not exist, go to next step.
16. Visually check fuel filler neck for cracks. If problem exists, replace fuel filler neck, install fuel tank and go to step  1 . If problem does not exist, install fuel tank and fuel filler neck, then go to step  1 .
17. Using hand vacuum pump, check for leaks in hoses "H" and "I" and pipe between hoses "H" and "I". See Fig 15 . If leak exists, replace hose or pipe, install fuel filler neck and go to step  1 . If leak does not exist, install fuel filler neck and go to step  1 .