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Home >> Mitsubishi >> 2003 >> Eclipse GS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.4L >> Diagnostic Tests >> DTC P0442: EVAP 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 3 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. If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed. 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 and repeat monitoring from the first step.
  2. 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  18 .
  3. Check for leaks in the evaporator line hose "A" to hose "C". Perform 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 any of the hoses are damaged, replace the inferior hose(s) and proceed to step  18 .
  4. 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 the chamber and proceed to step  18 .
  5. 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 ventilation solenoid is damaged, replace it and proceed to step  18 .
  6. 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. Note that "Pressure test" in this procedure refers to the I/M240 Simulation Test (8 simple steps) described in the evaporative emission system pressure pump manufacturer's instructions located in the lid of the pump box. If the evaporator line is in good condition, proceed to step  17 , otherwise, go to the next step.
  7. 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, proceed to step  10 .
  8. 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 any of the hoses are damaged, replace the defective hose(s), reinstall the fuel tank and proceed to step  18 .
  9. 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 in good condition, proceed to step  18 . If the evaporative emission canister is damaged, replace it, reinstall the fuel tank and proceed to step  18 .
  10. 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 the hose, reinstall the fuel filler neck protector and proceed to step  18 .
  11. 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 any of the hoses are damaged, replace the hose(s), reinstall the fuel tank and fuel filler neck assembly and proceed to step  18 .
  12. Check the check valve "A". The check valve should only allow air to pass in one direction. It is normal for air to leak from the check valve body. If check valve "A" is in good condition, go to the next step. If check valve "A" is damaged, replace it, reinstall the fuel tank and fuel filler neck assembly and proceed to step  18 .
  13. Check the check valve "B". This 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 check valve "B" is in good condition, go to the next step. If the check valve is damaged, replace it, reinstall the fuel tank and fuel filler neck assembly and proceed to step  18 .
  14. 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  18 .
  15. 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  18 .
  16. 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. Note: If these items are not securely plugged here, the fuel could leak in the next step. 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 filler neck assembly and proceed to step  18 .
  17. 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 3 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. If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed. 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 some 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.
  18. Carry out a test drive with the drive cycle pattern, refer to EVAP SYSTEM LEAK MONITOR  . Read the diagnostic trouble codes. If DTC P0442 is set, retry the troubleshooting from step  1 . If the DTC is absent, the inspection is complete.
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