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Home >> Mitsubishi >> 2002 >> Lancer ES, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0452: Evaporative Emission Control System Pressure Sensor Low Input >> Diagnostic Procedure
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Diagnostic Procedure

Required Special Tools are Scan Tool (MUT-II - MB991502) and Test Harness Set (MB991658).

CAUTION: To prevent damage to scan tool, always turn ignition switch to LOCK position before connecting or disconnecting scan tool.
  1. Connect scan tool to data link connector. Disconnect and plug hose "G" from evaporative emission canister. Turn ignition on. Remove fuel cap. Using scan tool, set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressure should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to fuel filler neck, and apply pressure. Scan tool reading should increase. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool reading is not within the specified value, go to next step. If scan tool reading is within the specified value, go to step  26 .
  2. Remove the rear seat cushion. Pull up on carpet. Using a DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14 terminal No. 11. Turn ignition on. Remove fuel cap. Voltage reading should be 2.0-3.0 volts. Using evaporative emission pump, apply pressure to fuel tank. Voltage reading should increase. Turn ignition switch to LOCK position. If voltage readings are as specified, go to next step. If voltage readings are not as specified, go to step  7 .
  3. Do not disconnect ECM harness connector C-117 (M/T) or PCM harness connector C-116 (A/T). Turn ignition on. Disconnect and plug hose "G" from evaporative emission canister. Using DVOM connected to ground, backprobe ECM harness connector C-117 terminal No. 61 or PCM harness connector C-116 terminal No. 92. Remove fuel cap. Voltage reading should be 2.0-3.0 volts. Using evaporative emission pump, apply pressure to fuel tank. Voltage reading should increase. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step  6 .
  4. Check for damage in intermediate harness connectors D-14 and ECM harness connector C-117 (M/T) or PCM harness connector C-116 (A/T). Repair or replace as necessary. After repairs, go to step  26 . If connectors are in good condition, go to next step.
  5. Disconnect and plug hose "G" from evaporative emission canister. Turn ignition on. Remove fuel filler cap. Set scan tool to data reading mode for item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressure should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect evaporative emission system pressure pump to fuel filler neck, and apply pressure. The scan tool reading should increase. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool reading is not within the specified value, replace ECM or PCM. After replacing ECM or PCM, go to step  26 . If the scan tool reading is within the specified value, problem is intermittent.
  6. Check for open or damage to harness between the fuel tank differential pressure sensor harness connector and ECM harness connector C-117 terminal No. 61 (M/T) or PCM harness connector C-116 terminal No. 92. Repair or replace as necessary. After repairs, go to step  26 . If circuits or connectors are okay, go to step  26 .
  7. Turn ignition on. Using DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14 terminal No. 9. Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to step  12 . If voltage reading is not as specified, go to next step.
  8. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Using DVOM connected to ground, backprobe ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step  10 .
  9. Check for open or damage in harness between 13-pin intermediate harness connector D-14 terminal No. 9 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair or replace as necessary. After repairs, go to step  26 . If circuits or connectors are okay, go to step  26 .
  10. Check for damage in 13-pin intermediate harness connector D-14 and ECM harness connector C-115 (M/T) or PCM harness connector C-118. Repair or replace as necessary. After repairs, go to step  26 . If connectors are okay, go to next step.
  11. Check for short to ground in circuit between 13-pin intermediate harness connector D-14 terminal No. 9 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair or replace as necessary. After repairs, go to step  26 . If circuit is okay, go to step  5 .
  12. Do not disconnect 13-pin intermediate harness connector D-14. Turn ignition on. Using DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14, terminal No. 10. Voltage reading should be 0.5 volt or less. Turn ignition off. If voltage reading is as specified, go to step  16 . If voltage reading is not as specified, go to next step.
  13. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Using DVOM connected to ground, backprobe ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Voltage reading should be 0.5 volt or less. If voltage is not as specified, go to step  15 . If voltage reading is as specified, go to next step.
  14. Check for open circuit or damage between intermediate harness connector D-14 terminal No. 10 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Repair or replace as necessary. After repairs, go to step  26 . If no problem is found, go to step  26 .
  15. Check for damage in ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Repair or replace as necessary. After repairs, go to step  26 . If connector is okay, go to step  5 .
  16. Remove fuel tank. Plug fuel filler hose, fuel pump feed nipple, return hose, hose "L" and hose "H" connected to fuel tank. Raise fuel tank closer to closer. Using Special Tool (MB991658), connect between fuel tank differential pressure harness connector and fuel tank differential pressure. Turn ignition on. Connect DVOM between ground and special tool connector terminal No. 1. Observe DVOM. When plug is removed from filler hose, voltage reading should be 2-3 volts. Using a evaporative emission pump, apply pressure to filler hose. Voltage should increase. Turn ignition off. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step  19 .
  17. Check harness connector at fuel tank differential pressure sensor and intermediate harness connector. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step  26 . If harness connectors are okay, go to next step.
  18. Check harness for short to ground between fuel tank differential pressure sensor harness connector terminal No. 1 and intermediate harness connector D-14 terminal No. 11. Repair as necessary. After repairs, reinstall fuel tank, then go to step  26 . If circuit is okay, reinstall fuel tank, then go to step  26 .
  19. Turn ignition on. Check voltage between ground and fuel tank differential pressure sensor terminal No. 3. Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to step  22 . If voltage reading is not as specified, go to next step.
  20. Check for damage in fuel tank differential pressure sensor harness connector and intermediate connector D-14. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step  26 . If harness connectors are okay, go to next step.
  21. Check for short circuit to ground between fuel tank differential pressure sensor harness connector terminal No. 3 and intermediate connector D-14 terminal No. 9. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step  26 . If circuit is okay, reinstall fuel tank and go to step  26 .
  22. Turn ignition on. Check voltage between ground and fuel tank differential pressure sensor harness connector terminal No. 2. Voltage reading should be 0.5 volt or less. Turn ignition off. If voltage reading is as specified, go to step  25 . If voltage reading is not as specified, go to next step.
  23. Check for damage in fuel differential pressure sensor harness connector and intermediate harness connector. Repair as necessary. After repairs, go to step  26 . If connectors are okay, go to next step.
  24. Check for short to ground between fuel tank differential pressure sensor harness connector terminal No. 2 and intermediate harness connector terminal No. 10. Repair as necessary. Reinstall fuel tank. After repairs, go to step  26 . If circuit is okay, reinstall fuel tank, then go to step  26 .
  25. Check for damage at fuel tank differential pressure sensor harness connector. Repair or replace as necessary. After repairs, go to next step. If connector is okay, replace fuel tank differential sensor. Reinstall fuel tank. After repairs, go to next step.
  26. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See EVAP SYSTEM LEAK MONITOR  under VERIFYING REPAIRS. Read DTCs. If DTC P0451 is reset, go to step  2 . If DTC P0451 is not reset, diagnosis is complete.
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