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Home >> Mitsubishi >> 2002 >> Eclipse GS, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self Diagnostics - 2.4L >> Diagnostic Tests >> DTC P0452: EVAP System Pressure Sensor Low Input >> Diagnostic Procedure
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Diagnostic Procedure

CAUTION: To prevent damage to Scan Tool (MB991502), always turn the ignition off before connecting or disconnecting the scan tool.
  1. Connect Scan Tool (MB991502) to the data link connector. Disconnect hose G from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Turn the ignition on. Remove the fuel cap. Set the scan tool to data reading mode for item 73, Fuel Tank Differential Pressure Sensor. The fuel tank pressure should be -1.5 to 1.5 kPa. Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition off and disconnect the scan tool. If the scan tool is reading within the specified value, go to step  28, otherwise, go to next step.
  2. Check the output circuit voltage at intermediate connector D-16. See Figure. Remove the rear seat cushion. Remove the protector. Disconnect intermediate connector D-16. Use Special Tools (MB991658 and MB991709) to connect terminals 5, 6 and 8 between connectors of the intermediate connector respectively. Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 5 and ground. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step  6.
  3. Check the output circuit voltage at ECM connector C-57 (M/T) or PCM connector C-57 (A/T) by backprobing. See Figure or Figure . Do not disconnect the ECM connector C-56 (M/T) or PCM connector C-57 (A/T). Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 61 (M/T) or terminal 92 (A/T) and ground by backprobing. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to step  27, otherwise, go to next step.
  4. Check connectors C-28, C-90, D-16 at intermediate connector and C-56 at ECM (M/T) or C-57 at PCM (A/T) for damage. See Figure, Figure or Figure . If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step  28.
  5. Check the harness wire between ECM connector C-56, terminal 61 (M/T) or PCM connector C-57, terminal 92 (A/T) and intermediate connector D-16, terminal 5 for damage. See Figure, Figure or Figure . If the harness wire is in good condition, go to step  28, otherwise, repair it and go to step  28.
  6. Check the 5 volts supply circuit voltage at intermediate connector D-16. See Figure. Disconnect intermediate connector D-16. Use Special Tools (MB991658 and MB991709) to connect terminals 5, 6 and 8 between connectors of the intermediate connector respectively. Turn the ignition on. Measure the voltage between terminal 8 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step  11, otherwise, go to next step.
  7. Check the 5 volts supply circuit voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. See Figure or Figure . Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 81 (M/T) or terminal 46 (A/T) and ground by backprobing. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step  9, otherwise, go to next step.
  8. Check connector C-60 at ECM (M/T) or C-54 at PCM (A/T) for damage. See Figure or Figure . If the connector is in good condition, go to step  27, otherwise, repair or replace it and go to step  28.
  9. Check connectors C-28, C-90, D-16 at intermediate connector for damage. See Figure. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step  28.
  10. Check the harness wire between ECM connector C-60, terminal 81 (M/T) or PCM connector C-54, terminal 46 (A/T) and intermediate connector D-16, terminal 8 for damage. See Figure, Figure or Figure . If the harness wire is in good condition, go to step  28, otherwise, repair it and go to step  28.
  11. Check the circuit voltage at intermediate connector D-16. See Figure. Disconnect intermediate connector D-16. Use Special Tool (MB991658) to connect terminal 6 between connectors and the intermediate connector. Turn the ignition on. Measure the voltage at the male side connector between terminal 6 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step  15.
  12. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. See Figure or Figure . Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step  28, otherwise, go to next step.
  13. Check connectors C-28, C-90, D-16 at intermediate connector and C-60 at ECM (M/T) or C-54 at PCM (A/T) for damage. See Figure, Figure or Figure . If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step  28.
  14. Check the harness wire between ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T) and intermediate connector D-16, terminal 6 for damage. See Figure, Figure or Figure . If the harness wire is in good condition, go to step  27, otherwise, repair it and go to step  28.
  15. Check the 5 volts supply circuit voltage at fuel tank differential pressure sensor connector D-18. See Figure. Remove the center exhaust pipe. Remove the fuel band assembly, tilt the fuel tank. Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminals 1, 2 and 3 of the connected sensor connector and those of the harness side connector respectively. Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step  18, otherwise, go to next step.
  16. Check connectors D-16 at intermediate connector and D-18 at fuel tank differential pressure sensor for damage. See Figure and Figure . If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step  28.
  17. Check the harness wire between intermediate connector D-16, terminal 8 and fuel tank differential pressure sensor connector D-18, terminal 3 for damage. If the harness wire is in good condition, go to step  28, otherwise, repair it and go to step  28.
  18. Check the ground circuit voltage at fuel tank differential pressure sensor connector D-18. See Figure. Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminal 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Measure the voltage at the fuel tank differential pressure sensor side connector between terminal 2 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, replace the fuel tank differential pressure sensor and go to step  28.
  19. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. See Figure or Figure . Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step  28, otherwise, go to next step.
  20. Check connectors C-28, C-90, D-16 at intermediate connector and C-60 at ECM (M/T) or C-54 at PCM (A/T) and D-18 at fuel tank differential pressure sensor for damage. See Figure, FigureFigure or Figure . If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step  28.
  21. Check the harness wire between ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T) and fuel tank differential pressure sensor connector D-18, terminal 2 for damage. See Figure, Figure or Figure . If the harness wire is in good condition, go to next step, otherwise, repair it and go to step  28.
  22. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. See Figure or Figure . Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step  27.
  23. Check the output circuit voltage at fuel tank differential pressure connector D-18. See Figure. Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminals 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 1 and ground. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, replace the fuel tank differential pressure sensor and go to step  28.
  24. Check the output circuit voltage at ECM connector C-56 (M/T) or PCM connector C-57 (A/T) by backprobing. See Figure or Figure . Do not disconnect the ECM connector C-56 (M/T) or PCM connector C-57 (A/T). Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 61 (M/T) or terminal 92 (A/T) and ground by backprobing. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to step  27, otherwise, go to next step.
  25. Check connectors C-28, C-90, D-16 at intermediate connector and C-56 at ECM (M/T) or C-57 at PCM (A/T) and D-18 at fuel tank differential pressure sensor for damage. See Figure, Figure, Figure or Figure . If the connectors are in good condition, go to next step, otherwise, repair or replace it and go to step  28.
  26. Check the harness wire between ECM connector C-56, terminal 61 (M/T) or PCM connector C-57, terminal 92 (A/T) and fuel tank differential pressure sensor connector D-18, terminal 1 for damage. See Figure, Figure or Figure . If the harness wire is in good condition, go to step  28, otherwise, repair it and go to step  28.
  27. Connect scan tool to the data link connector. Disconnect hose G from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Turn the ignition on. Remove the fuel cap. Set the scan tool to data reading mode for item 73, Fuel Tank Differential Pressure Sensor. The fuel tank pressure should be -1.5 to 1.5 kPa. Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition off and disconnect the scan tool. If the scan tool is reading within the specified value, the malfunction is intermittent, refer to INTERMITTENT DIAGNOSTIC TROUBLE CODES . If the scan tool is reading out of range, replace the ECM (M/T) or PCM (A/T) and go to next step.
  28. Carry out a test drive with the drive cycle pattern (OBD-II). See EVAP SYSTEM LEAK MONITOR . Read the diagnostic trouble codes. If DTC P0452 is set, retry the troubleshooting. If the DTC is absent, the inspection is complete.
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