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Home >> Mitsubishi >> 2003 >> Eclipse RS, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.4L >> Diagnostic Tests >> DTC P0456: EVAP Control System Small Leak Detected >> 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 it.
CAUTION: With this monitor, the ECM (M/T) or PCM (A/T) automatically increases the engine speed to 1,600 RPM or more. Check that the transaxle is set to "neutral" (M/T) or "P" (A/T) position.
  1. Connect scan tool (MB991502) to the data link connector. Turn the ignition on. Erase the DTCs using the scan tool. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.) Start the engine. Select "System Test", and press the "YES" key. Select "Evap Leak Mon", and press the "YES" key. During the monitor, keep the accelerator pedal at the idling position.
    NOTE: If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed.
  2. Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on the scan tool will change from "NO" to "YES". Turn the ignition off and disconnect the scan tool. If the scan tool shows "Evap Leak Mon. Completed. Test Passed": The evaporative emission system is working properly at this time. Explain to the customer that improperly tightened fuel cap can cause MIL to turn on, and return the vehicle. If the scan tool shows "Evap Leak Mon. Completed. Test Failed and DTCs Set": A malfunction has been detected during the monitor test, go to the next step. If the scan tool shows "Evap Leak Mon. Discontinued. Retest again from the first": The monitor was discontinued for some reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn the ignition off once and repeat the monitoring from step  1 .
  3. Check evaporative emission purge solenoid for leaks: Remove the battery. Remove the air intake hose. Disconnect hose "B" from the evaporative emission purge solenoid side, and connect a hand vacuum pump to the nipple of the evaporative emission purge solenoid. Apply a pressure on the hand vacuum pump, and confirm that air is maintained. Disconnect the hand vacuum pump, and connect hose "B" to the evaporative emission purge solenoid. If the evaporative emission purge solenoid is in good condition, go to the next step. If the evaporative emission purge solenoid is damaged, replace it and proceed to step  19 .
  4. Check for leaks in the evaporator line hose "A" to hose "C". The leakage test with a hand vacuum pump on each hose from hose "A" to hose "C". If the hoses are in good condition, go to the next step. If the hoses are damaged, replace as necessary and proceed to step  19 .
  5. Check for leaks in the chamber. Connect a hand vacuum pump to the nipple. Plug the other nipple. Apply vacuum with the hand vacuum pump, and confirm that the applied vacuum does not fluctuate. If the chamber is in good condition, go to the next step. If the chamber is damaged, replace it and proceed to step  19 .
  6. Connect scan tool (MB991502) to the data link connector. Disconnect the hose "E" from the evaporative emission ventilation solenoid side. Connect the hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hoses have been disconnected. Turn the ignition on. Set the scan tool to actuator test mode for item 29, Evaporative Emission Ventilation Solenoid. When the evaporative emission ventilation solenoid is operated, apply a pressure on the hand vacuum pump and confirm that air is maintained. Turn the ignition off and disconnect the scan tool. Disconnect the hand vacuum pump, and connect hose "E" to the evaporative emission canister. If the evaporative emission ventilation solenoid is in good condition, go to the next step. If the evaporative emission solenoid is damaged, replace it and proceed to step  19 .
    7. NOTE: "Pressure test" in this procedure refers to the I/M240 Simulation Test (8 simple steps) described in the evaporative emission system pressure pump (Miller number 6872A) manufacturer's instructions located in the lid of the pump box.
  7. Pressure test for evaporator line from hose "D" to hose "N": Remove the module bracket mounting bolts, and disconnect hose "E" from the evaporative emission ventilation solenoid side, and plug the hoses from which the hoses have been disconnected. Confirm that the evaporative emission system pressure pump (Miller number 6872A) is operating properly. Perform the self-test as described in the manufacturer's instructions. Connect an evaporative emission system pressure pump to the fuel filler neck. Pressure test the system to determine whether any leaks are present. If the evaporator line is in good condition, proceed to step  18 , otherwise, go to the next step.
  8. Pressure test for evaporator line from hose "G" to hose "N". Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Perform the pressure test again. If the evaporator line is in good condition, go to the next step. If the evaporator line is damaged, repair it and proceed to step  11 .
  9. Check for leaks in the evaporator line hose "D" to hose "F". Remove the fuel tank. The leakage test with a hand vacuum pump on each hose from hose "D" to hose "F". If the hoses are in good condition, go to the next step. If the hoses are damaged, replace hose(s), reinstall the fuel tank and proceed to step  19 .
  10. Check for leaks in the evaporative emission canister. Connect a hand vacuum pump to the vent nipple of the evaporative emission canister. Plug the other two nipples or loop a hose between the other nipples. Apply a vacuum with the hand vacuum pump, and confirm that the applied vacuum does not fluctuate. If the evaporative emission canister is damaged, replace it and reinstall the fuel tank. Proceed to step  19 .
  11. Check for leaks in the evaporator line from hose "H" and hose "I". Remove the fuel filler neck protector. Disconnect hose "H" at the liquid separator, and then connect a hand vacuum pump to the hose. Disconnect hose "I" at the fuel tank side, and then plug the hose. Apply vacuum with the hand vacuum pump, and confirm that the applied vacuum does not fluctuate. If the evaporator line is in good condition, go to the next step. If the evaporator line is damaged, replace that hose, reinstall the fuel filler neck protector and proceed to step  19 .
  12. Check for leaks in the evaporator line hose "G", "J", "K", "L" and "M". Remove the fuel tank and fuel filler neck assembly. The leakage test with a hand vacuum pump on each hose from hose "G", "J", "K", "L" and "M". If the hoses are in good condition, go to the next step. If the hose(s) are damaged, replace as necessary, reinstall the fuel tank, fuel filler neck assembly and proceed to step  19 .
  13. Check the check valve "A". The check valve should only allow air to flow in one direction. It is normal for air to leak from the valve body. If the check valve "A" is in good condition, go to the next step. If the check valve is damaged, replace the check valve "A", reinstall the fuel tank and fuel filler neck assembly and proceed to step  19 .
  14. Check the check valve "B". The valve should allow more air to pass in one direction than the other. It is normal for air to leak from the valve body. If the check valve "B" is in good condition, go to the next step. If the check valve "B" is damaged, replace it, reinstall the fuel tank and fuel filler neck assembly and proceed to step  19 .
  15. Check for leaks in the evaporator line hose "N". The leakage test with a hand vacuum pump on each hose from hose "N". If the hose is in good condition, go to the next step. If the hose is damaged, replace it, reinstall the fuel tank and fuel filler neck assembly and proceed to step  19 .
  16. Visually check for cracks in the fuel filler neck assembly. If the fuel filler neck assembly is in good condition, go to the next step. If the fuel filler neck assembly is damaged, replace it, reinstall the fuel tank and fuel filler neck assembly and proceed to step  19 .
  17. Check for leaks in the fuel tank. Carefully check the fuel pump assembly and the inner pressure sensor installation section in the fuel tank. Connect an evaporative emission system pressure pump to the leveling valve nipple. Plug the filler hose, feed pipe, return pipe and rollover valve nipple connected to the fuel tank. Make sure they are securely plugged or fuel could leak. Apply pressure with the evaporative emission system pressure pump. In the pressurized state, check for the leak by applying soap water, etc to each section. If the fuel tank is in good condition, go to the next step. If the fuel tank is damaged, replace it, reinstall the fuel tank and fuel filler neck assembly and proceed to step  19 .
    18. CAUTION: With this monitor, the ECM (M/T) or PCM (A/T) automatically increases the engine speed to 1,600 RPM or more. Check that the transaxle is set to "neutral" (M/T) or "P" (A/T) position.
    NOTE: If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed.
  18. Connect scan tool (MB991502) to the data link connector. Turn the ignition on. Erase the DTCs with the scan tool. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.) Start the engine. Select "System Test" and press the "YES" key. Select "Evap Leak Mon" and press the "YES" key. During the monitor, keep the accelerator pedal at the idling position. Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on the scan tool will change from "NO" to "YES". Turn the ignition off and disconnect the scan tool. If the scan tool shows "Evap Leak Mon. Completed. Test Passed": The evaporative emission system is working properly at this time, go to the next step. If the scan tool shows "Evap Leak Mon. Completed. Test Failed and DTCs Set", replace the ECM (M/T) or PCM (A/T) and go to the next step. If the scan tool shows "Evap Leak Mon. Discontinued. Retest again from the first", the monitor was discontinued for a certain reason (vehicle speed input from ECM (M/T) or PCM (A/T), engine speed and engine load deviating from specified range). Turn the ignition off once, and recheck evaporative emission system monitor test.
  19. Carry out a test drive with the drive cycle pattern, refer to EVAP SYSTEM LEAK MONITOR  . Read the diagnostic trouble codes. If the DTC P0456 is set, retry the troubleshooting. If the DTC is absent, the diagnosis is complete.
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