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Home >> Chevrolet >> 1998 >> Malibu Base, 2.4 T >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Testing & Engine Component Testing - 2.4L >> Emission Systems & Sub-Systems >> EVAP Control System Diagnosis
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EVAP Control System Diagnosis

NOTE: Ensure all vacuum line and EVAP system components are not damaged or missing before proceeding with this test.
  1. If powertrain OBD system check has been performed, go to next step. If powertrain OBD system check has not been performed, perform powertrain OBD system check. See POWERTRAIN OBD SYSTEM CHECK in TESTS W/CODES - 2.4L article.
  2. Connect scan tool to data link connector. Turn ignition switch to RUN position. Retrieve DTCs. If no DTCs exist, go to next step. If any DTCs exist, perform appropriate DTC test. See TESTS W/CODES - 2.4L article.
  3. Using scan tool, command EVAP canister purge valve and EVAP canister vent valve on and off. If both purge valve and vent valve click when toggled on and off, go to next step. If either purge valve or vent valve do not click when toggled on and off, perform PCM output diagnosis. See PCM OUTPUT DIAGNOSIS under COMPUTERIZED ENGINE CONTROLS.
  4. Turn ignition switch to LOCK position. Remove fuel filler cap. Turn ignition switch to RUN position. Observe fuel tank pressure on scan tool. If zero in. Hg exists, go to next step. If zero in. Hg does not exist, perform DTC P0452 or DTC P0453 test. See TESTS W/CODES - 2.4L article.
  5. Install fuel filler cap. Connect Enhanced Pressure Purge Diagnosis Tester (J-41413) to EVAP service port. Using scan tool, command EVAP vent valve on. Pressurize EVAP system to .47 in. Hg. Observe fuel tank pressure on scan tool. If .47 in. Hg is displayed, go to next step. If .47 in. Hg is not displayed, perform DTC P0452 or DTC P0453 test. See TESTS W/CODES - 2.4L article.
  6. Observe EVAP system pressure on diagnostic tester. Using scan tool, command EVAP canister vent valve off. If EVAP system pressure decreases to zero in. Hg within 5 seconds, go to next step. If EVAP system pressure does not decrease to zero in. Hg within 5 seconds, perform DTC P0446 test. See TESTS W/CODES - 2.4L article.
  7. Start engine. Remove gas cap. Using scan tool seal EVAP system. Install fuel filler cap. Increase engine speed to 1500 RPM. Observe fuel tank pressure on scan tool. If fuel tank pressure does not decrease, go to next step. If fuel tank pressure is decreasing, perform DTC P1441 test. See TESTS W/CODES - 2.4L article.
  8. Using scan tool, command EVAP canister vent valve and EVAP canister purge valve on. Increase engine speed to 1500 RPM. Observe fuel tank pressure on scan tool. If fuel tank pressure is decreasing, system is okay at this time. If fuel tank pressure does not decrease, perform DTC P0440 test. See TESTS W/CODES - 2.4L article.
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