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Home >> Chevrolet >> 2001 >> Metro >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics - 1.3L >> Diagnostic Tests >> DTC P0440: EVAP System >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing powertrain diagnostic system check, go to next step.
  2. If other EVAP DTCs except P0455 are set, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no other EVAP DTCs are set, go to next step.
  3. Check vacuum hoses for proper routing. Check for missing or damaged components. Ensure wiring harness connections to EVAP components are clean and tight. Check fuel filler cap for a tight seal. If a problem is found, go to step  40. If no problem is found, go to next step.
  4. Check for manifold vacuum at EVAP canister purge solenoid valve. If a problem is found, repair as necessary, go to step  40. If no problem is found, go to next step.
    WARNING: DO NOT siphon air from EVAP system components and/or hoses. Fuel vapor inside components is harmful.
  5. Turn ignition on, with engine off. Disconnect EVAP canister purge solenoid valve vacuum hoses at intake manifold and EVAP canister. Blow air into EVAP canister purge solenoid valve vacuum hose disconnected from EVAP canister. Air should not pass through EVAP canister purge solenoid valve and exit out intake manifold hose. Using scan tool, command EVAP canister purge solenoid valve on and adjust duty cycle to 100 percent. Blow air into EVAP canister purge solenoid valve vacuum hose disconnected from EVAP canister. Air should pass through EVAP canister purge solenoid valve and exit out intake manifold hose. If airflow through EVAP canister purge solenoid valve is as described, go to step  8. If airflow through EVAP canister purge solenoid valve is not as described, go to next step.
  6. Using test light connected to ground, probe EVAP canister purge solenoid valve harness connector ignition positive voltage circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step  33.
  7. Using test light connected to battery voltage, probe EVAP canister purge solenoid valve harness connector control circuit. Using scan tool, command EVAP canister purge solenoid valve on. Adjust duty cycle from zero percent to 100 percent while monitoring test light. If test light flashes near zero percent and illuminates steady near 100 percent duty cycle, go to step  37. If test light does not flash or illuminate as specified, go to step  36.
  8. Remove fuel filler cap. Install Gas Cap Adapter (J-41415-30). Connect EVAP Pressure/Purge Diagnostic Station (J-41413) to gas cap adapter. Using scan tool, command EVAP canister vent solenoid off. Using EVAP pressure/purge diagnostic station, pressurize EVAP system to 15 in. H2O. Monitor pressure on diagnostic station gauge. Turn rotary switch on station to HOLD position. Observe EVAP pressure gauge. If pressure decreases to less than 10 in. H2O within 2 minutes, go to next step. If pressure holds at 10 in. H2O or greater, go to step  10.
  9. Using scan tool, command EVAP canister vent solenoid on. Using EVAP pressure/purge diagnostic station, pressurize EVAP system to 15 in. H2O. Monitor pressure on diagnostic station gauge. Turn rotary switch on station to HOLD position. Observe EVAP pressure gauge. If pressure decreases to less than 10 in. H2O within 2 minutes, go to step  11. If pressure holds at 10 in. H2O or greater, go to step  16.
  10. With EVAP system still pressurized to 10 in. H2O, turn EVAP tank pressure control solenoid vacuum valve on and observe EVAP pressure gauge. If pressure decreases to zero, go to next step. If pressure does not decrease to zero, go to step  15.
  11. Using scan tool, command EVAP canister vent solenoid on. Using EVAP pressure/purge diagnostic station, attempt to pressurize EVAP system to 30 in. H2O. Using Ultrasonic Leak Detector (J-41416), check for any leaks in EVAP system. Lower fuel tank as necessary to inspect EVAP connections on top of tank. If leaks are present, go to next step. If no leaks are present, go to step  13.
  12. Replace any leaking or faulty EVAP control system components. Replace any leaking EVAP lines or hoses. Repair or replace leaking or stuck open EVAP canister vent solenoid. After repairs, go to step  40.
  13. Turn ignition off. Remove fuel filler cap. Turn ignition on, with engine off. Using scan tool, monitor fuel tank pressure sensor parameter. If fuel tank pressure sensor value is 0.0-0.5 in. H2O, go to next step. If fuel tank pressure sensor value is not 0.0-0.5 in. H2O, go to DTC P0450. See DTC P0450 .
  14. Using scan tool, clear DTC information and place vehicle into check mode. Operate vehicle within FREEZE FRAME/FAILURE RECORDS data conditions. If DTC P0440 or P0455 resets, go to step  19. If DTC P0440 or P0455 does not reset, see DIAGNOSTIC AIDS .
  15. Using scan tool, command EVAP canister vent solenoid on and off while listening for solenoid to click on and off. If solenoid can be heard clicking on and off, go to step  25. If solenoid cannot be heard clicking on and off, go to step  19.
  16. Turn ignition off. Check for short to ground in Yellow wire between EVAP tank pressure control solenoid valve and PCM harness connector C1 terminal No. 16. See Figure. Repair as necessary. After repairs, go to step  40. If circuit is okay, go to next step.
    WARNING: DO NOT siphon air from EVAP system components and/or hoses. Fuel vapor inside components is harmful.
    NOTE: Fuel tank pressure control valve will not allow air to flow from tank side port to canister side port until pressure is greater than .5 psi (.04 kg/cm2 ).
  17. Remove fuel tank. Remove both fuel tank pressure control valves. Blow hard through tank side port of fuel tank pressure control valve. If air flows through valve to canister port side, go to next step. If air does not pass through valve, go to step  35.
  18. Gently blow air through canister side port of fuel tank pressure control valve. Air should flow easily through valve to tank port side. If airflow is as described, go to step  27. If air does not flow as described, go to step  35.
  19. Remove rear seat cushion. Disconnect EVAP canister vent solenoid harness connector. Connect a test light between EVAP canister vent solenoid harness connector terminals. Using scan tool, command EVAP canister vent solenoid on and off while observing test light. If test light illuminates only when solenoid is commanded on, go to step  21. If test light does not illuminate, go to next step.
  20. Turn ignition off. Check for open in White/Blue wire between EVAP canister vent solenoid and relay block (located near battery). Check for open or short in Red/Green wire between EVAP canister vent solenoid and PCM harness connector C1 terminal No. 3. Repair as necessary. After repairs, go to step  40. If circuits are okay, go to step  39.
  21. Turn ignition off. Remove fuel tank. Check EVAP system lines, hoses and connections for any blockage or restrictions. Repair as necessary. After repairs, go to step  40. If lines, hoses and connections are okay, go to next step.
  22. Remove EVAP canister vent solenoid (located on top of fuel tank). Using a hand-held vacuum pump, apply 15 in. Hg of vacuum to canister side of EVAP canister vent solenoid. If solenoid holds vacuum, go to step  34. If solenoid does not hold vacuum, go to next step.
  23. Apply 12 volts to EVAP canister vent solenoid. Using a hand-held vacuum pump, apply 15 in. Hg of vacuum to canister side of EVAP canister vent solenoid. If solenoid holds vacuum, go to next step. If solenoid does not hold vacuum, go to step  34.
  24. Check for open or short in Red/Green wire between EVAP canister vent solenoid and harness side connector C311 (located under rear seat). Repair as necessary. After repairs, go to step  40. If wiring harness is okay, go to step  31.
  25. Remove rear seat cushion. Disconnect EVAP tank pressure control solenoid valve harness connector C311. Turn ignition on, with engine off. Connect a test light between EVAP tank pressure control solenoid valve harness connector terminals. Using scan tool, command EVAP tank pressure control solenoid valve on and off while observing test light. If test light illuminates only when solenoid is commanded on, go to step  26. If test light does not illuminate, go to step  30.
  26. Turn ignition off. Remove fuel tank. Check EVAP tank pressure control solenoid valve lines, hoses and connections for any blockage or restrictions. Repair as necessary. After repairs, go to step  40. If lines, hoses and connections are okay, go to next step.
    WARNING: DO NOT siphon air from EVAP system components and/or hoses. Fuel vapor inside components is harmful.
  27. Remove EVAP tank pressure control solenoid valve. Blow through the side port of EVAP tank pressure control solenoid valve. If air flows through valve to the top port of EVAP tank pressure control solenoid valve, go to step  38. If air does not pass through valve, go to next step.
  28. Apply 12 volts to EVAP tank pressure control solenoid valve. Blow through the side port of EVAP tank pressure control solenoid valve. If air flows through valve to the top port of EVAP tank pressure control solenoid valve, go to next step. If air does not pass through valve, go to step  38.
  29. Repair open or short in Yellow wire between EVAP tank pressure control solenoid valve and connector C311. After repairs, go to step  40.
  30. Turn ignition off. Check for open in White/Blue wire between EVAP tank pressure control solenoid valve and relay block (located near battery). Check for open or short in Yellow wire between EVAP tank pressure control solenoid valve and PCM harness connector C1 terminal No. 16. See Figure. Repair as necessary. After repairs, go to step  40. If circuits are okay, go to step  39.
    WARNING: DO NOT siphon air from EVAP system components and/or hoses. Fuel vapor inside components is harmful.
  31. Disconnect EVAP canister vapor hose at fuel limiter vent valve. Disconnect the other 3 hoses from EVAP vapor canister. Blow air into hose connected to EVAP canister tank port. Air should flow through canister and exist other 3 ports. If air flows through canister and exists other 3 ports, see DIAGNOSTIC AIDS . If air does not flow as specified, go to next step.
  32. Turn ignition off. Replace EVAP canister. After replacing canister, go to step  40.
  33. Turn ignition off. Repair open in White/Blue wire between EVAP canister purge valve and main relay (located in relay block, near battery). After repairs, go to step  40.
  34. Replace EVAP canister vent solenoid. After replacing solenoid, go to step  40.
  35. Replace faulty EVAP fuel tank pressure control solenoid valve. After replacing control solenoid valve, go to step  40.
  36. Turn ignition off. Check for open or short in Red/Green wire between EVAP canister purge valve and PCM harness connector C1 terminal No. 7. Repair as necessary. After repairs, go to step  40. If circuit is okay, go to step  39.
    NOTE: EVAP canister may have released carbon particles causing EVAP canister purge valve failure. To prevent damage to other EVAP system components, check EVAP canister for loose carbon.
  37. Replace EVAP canister purge solenoid valve. After replacing purge solenoid valve, go to step  40.
  38. Replace EVAP fuel tank pressure control solenoid valve. After replacing solenoid valve, go to step  40.
  39. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  40. Turn ignition on, with engine off. Using scan tool, clear DTC information. Operate vehicle within FREEZE FRAME/FAILURE RECORDS data conditions that set DTC. Check for DTCs. If no DTCs are stored, repair is complete. If any DTCs are stored, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
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