P0455
DTC P0455: Evaporative Emission System Leak Detected (Gross Leak)System Diagram:
TECHNICAL DESCRIPTION
- The fuel tank may be under a slight pressure or vacuum depending on the state of the evaporative emission (EVAP) system. The ECM monitors and responds to these pressure/vacuum changes. If the pressure/vacuum varies from the specified range, the ECM will set DTC P0455.
- The ECM energizes the evaporative emission ventilation solenoid to shut off the evaporative emission canister outlet port.
- The evaporative emission purge solenoid is activated to apply engine manifold vacuum to the EVAP system.
- When the fuel system develops a vacuum of 2 kPa (0.29 psi), the evaporative emission purge solenoid is turned "off" and the fuel system vacuum is maintained at 2 kPa (0.29 psi).
- The ECM determines whether there is a leak or clog in the fuel system by measuring the change in vacuum inside the fuel tank.
- The test is stopped when fuel vapor pressure is determined to be too high.
DESCRIPTIONS OF MONITOR METHODS
- Depressurizing EVAP system by intake manifold negative pressure is impossible within specified period.
MONITOR EXECUTION
- Once per driving cycle.
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Evaporative emission purge solenoid monitor
- Evaporative emission purge system monitor
- Fuel tank differential pressure sensor monitor
- Evaporative emission ventilation solenoid monitor
- Fuel level sensor monitor
- Fuel temperature sensor monitor
Sensor (The sensors below are determined to be normal)
- Volume airflow sensor
- Barometric pressure sensor
- Intake air temperature sensor
- Engine coolant temperature sensor
Logic Flow Charts (Monitor Sequence):
LOGIC FLOW CHARTS (Monitor Sequence)
DTC SET CONDITIONS
Check Conditions A: At Start up
- Intake air temperature is 36 degrees C (97 degrees F) or less upon engine start up.
- The engine coolant temperature is 36 degrees C (97 degrees F) or less upon engine start up.
Check Conditions B: For Test to Run
- Engine coolant temperature is greater than 60 degrees C (140 degrees F) When the amount of remaining fuel is 15 - 40 percent of capacity upon engine start up.
- Engine coolant temperature is greater than 20 degrees C (68 degrees F) when the amount of remaining fuel is 40 - 85 percent of capacity upon engine start up.
- The engine speed is greater than or equal to 1,600 r/min.
- Barometric pressure is greater than 76 kPa (11 psi).
- Volumetric efficiency is between 20 and 70 percent.
- The fuel temperature is 36 degrees C (97 degrees F) or less.
- The fuel tank differential pressure sensor output voltage is 1 - 4 volts.
Check Conditions C: For Test to Stop
- The intake air temperature is greater than 5 degrees C (41 degrees F).
- When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure in the fuel tank rises to 451 Pa (0.065 psi) or less and the amount of remaining fuel is 15 - 40 percent of capacity upon engine start up.
- When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure in the fuel tank rises to 324 Pa (0.047 psi) or less and the amount of remaining fuel is 40 - 85 percent of capacity upon engine start up.
- 10 seconds have elapsed from the start of the previous monitoring.
- Monitoring time: 170 seconds.
Judgment Criterion
- The fuel tank internal pressure is greater than 2 kPa (0.29 psi) after the evaporative emission purge solenoid has been driven when the fuel tank and vapor line were closed.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 5. OBD-II Drive Cycle Pattern Lists
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
- Loose fuel cap.
- Fuel cap relief pressure is incorrect.
- Fuel overflow limiter valve failed.
- Purge line or vapor line is clogged.
- Fuel tank, purge line or vapor line seal failed.
- Evaporative emission purge solenoid valve failed.
- Evaporative emission ventilation solenoid valve failed.
- Fuel tank differential pressure sensor failed.
- Evaporative emission canister seal is faulty.
- Evaporative emission canister is clogged.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
STEP 1. Using scan tool MB991958, check the evaporative emission system monitor test.
CAUTION:
- To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
- During this test, the ECM will automatically increase the engine speed to 1,600 r/min or greater. Check that the transaxle is set to the neutral position.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Erase the DTCs using scan tool MB991958.
4. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.)
5. Start the engine.
6. Select "System Test."
7. Select "Evap Leak Mon."
8. During this test, keep the accelerator pedal at the idle position.
9. Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on scan tool MB991958 will change from "NO" to "YES."
10. Turn the ignition switch to the "LOCK" (OFF) position, and disconnect scan tool MB991958.
Q: Is "Evap Leak Mon. Completed. Test Failed and DTCs Set" displayed on scan tool MB991958?
YES: A malfunction has been detected during the monitor test. Refer to the Diagnostic Trouble Code Chart and diagnose any other DTCs that are set. Diagnostic Trouble Code Descriptions If no other DTC's have been set, go to Step 2.
NO: If "Evap Leak Mon. Completed. Test Passed" is displayed on scan tool MB991958, the evaporative emission system is working properly at this time. Explain to the customer that an improperly tightened fuel cap can cause the MIL to turn on. Return the vehicle to the customer.
NO: If "Evap Leak Mon. Discontinued. Retest again from the first" is displayed on scan tool MB991958, the EVAP monitor has been interrupted during the test. Turn the ignition switch to the "LOCK" (OFF) position once, and repeat the monitoring from Step 1.
STEP 2. Using scan tool MB991958, check actuator test item 08: Evaporative Emission Purge Solenoid Valve.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Disconnect hoses C and D from the evaporative emission purge solenoid valve side, and connect the hand vacuum pump to the evaporative emission purge solenoid valve instead of hose D.
3. Turn the ignition switch to the "ON" position.
4. Set scan tool MB991958 to actuator test mode for item 08: Evaporative Emission Purge Solenoid Valve. When the evaporative emission purge solenoid valve is operated, apply a pressure on the hand vacuum pump and confirm that air is blown from the other side nipple.
5. Turn the ignition switch to the "LOCK" (OFF) position.
6. Disconnect the hand vacuum pump, and connect hoses C and D to the evaporative emission purge solenoid valve.
Q: Is the solenoid valve in good condition?
YES: Go to Step 3.
NO: Replace the evaporative emission purge solenoid valve. Go to Step 21.
STEP 3. Check for leaks and clogging in evaporative emission system hoses A through E. Use a hand vacuum pump to test each hose from hose A to hose E.
Q: Are the hoses in good condition?
YES: Go to Step 4.
NO: Replace the damaged hose. Go to Step 21.
STEP 4. Test check valve A.
1. Check valve A is a one-way check valve.
2. Check valve A should allow air to flow in only one direction.
Q: Does check valve A allow air to pass in one direction only?
YES: Go to Step 5.
NO: Replace check valve A. Go to Step 21.
STEP 5. Using scan tool MB991958, check the evaporative emission ventilation solenoid and hose H.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Disconnect hose H from the evaporative emission canister side, and connect a hand vacuum pump.
3. Turn the ignition switch to the "ON" position.
4. Set scan tool MB991958 to actuator test mode for item 29: Evaporative Emission Ventilation Solenoid Valve. While the evaporative emission ventilation solenoid valve is activated, operate the hand vacuum pump and confirm that the solenoid holds vacuum.
5. Turn the ignition switch to the "LOCK" (OFF) position and disconnect scan tool MB991958.
6. Disconnect the hand vacuum pump, and connect hose H to the evaporative emission canister.
Q: Did the evaporative emission ventilation solenoid and hose F hold vacuum?
YES: Go to Step 7.
NO: Go to Step 6.
STEP 6. Check for leaks in the evaporative emission system hose H. Perform a vacuum test using a hand vacuum pump on hose H.
Q: Is the hose in good condition?
YES: Replace the evaporative emission ventilation solenoid. Refer to, Evaporative Emission Canister and Fuel Tank Pressure Relief Valve. Go to Step 21.
NO: Replace the damaged hose. Go to Step 21.
STEP 7. Check for leaks and clogging in evaporative emission system hoses F and G. Perform a vacuum test using a hand vacuum pump on hoses F and G.
Q: Are the hoses in good condition?
YES: Go to Step 8.
NO: Replace the damaged hose. Go to Step 21.
STEP 8. Pressure test the evaporative emission system lines from hoses I to O.
1. Disconnect hose I from the canister, and plug hose I securely.
2. 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.
3. Remove the fuel cap.
4. Connect the evaporative emission system pressure pump to the fuel tank filler tube.
5. Pressure test the system to determine whether any leaks are present.
NOTE: The "Pressure test" in this procedure refers to the I/M240 Simulation Test. The eight steps of this test are described in the manufacturer's instructions for the evaporative emission system pressure pump, Miller number 6872A.
6. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
7. Connect hose I to the canister.
Q: Is the evaporative emission system line free of leaks?
YES: Go to Step 15.
NO: Go to Step 9.
STEP 9. Check for vacuum leaks in evaporative emission system hoses I, K, L and M.
1. Remove the fuel tank filler tube protector (Refer to, Fuel Tank).
2. Perform a leakage test with a hand vacuum pump on each hose from hoses I, K, L and M.
Q: Do the hoses hold vacuum?
YES: Go to Step 10.
NO: Replace the damaged hose, and reinstall the fuel tank filler tube protector. Refer to, Fuel Tank. Go to Step 21.
STEP 10. Test check valve B.
1. Check valve B is a one-way check valve.
2. Check valve B should allow air to flow in only one direction.
Q: Does check valve B allow air to pass in one direction only?
YES: Go to Step 11.
NO: Replace check valve B, and reinstall the fuel tank filler tube protector. Refer to, Fuel Tank. Go to Step 21.
STEP 11. Check for vacuum leaks in evaporative emission system hoses J, N and O.
1. Remove the fuel tank.
2. Perform a leakage test with a hand vacuum pump on each hose J, N and O.
Q: Are the hoses in good condition?
YES: Go to Step 12.
NO: Replace the damaged hose, and reinstall the fuel tank. Go to Step 21.
STEP 12. Test check valve C.
1. Check valve C is a one-way check valve.
2. Check valve C should allow air to flow in only one direction.
Q: Does check valve C allow air to pass in one direction only?
YES: Go to Step 13.
NO: Replace check valve C, and reinstall the fuel tank and the fuel tank filler tube protector. Go to Step 21 .
STEP 13. Check for leaks in the fuel tank.
1. Visually check for cracks or other leaks in the fuel tank.
NOTE: Carefully check the fuel pump assembly and the differential pressure sensor installation in the fuel tank.
2. Connect an evaporative emission system pressure pump (Miller number 6872A) to the filler hose.
3. Plug the hose shown in the illustration.
NOTE: If these items are not securely plugged here, the fuel could leak in the next step.
4. Pressurize the fuel tank with the evaporative emission system pressure pump.
5. In the pressurized state, check for leaks by applying a soapy water solution to each section and look for bubbles.
Q: Are any leaks found?
YES: When there is a leak from the attachment points of the fuel pump assembly, fuel tank differential pressure sensor, leveling valve or fuel tank rollover valve, reassemble the leaked parts and check again that there are no leaks. Then reinstall the fuel tank. Go to Step 21 .
YES: When there is a leak from the fuel tank, replace the fuel tank. Go to Step 21.
NO: When there is no leak, reinstall the fuel tank. Go to Step 14.
STEP 14. Using scan tool MB991958, check the evaporative emission system monitor test.
CAUTION:
- To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
- During this test, the ECM automatically increases the engine speed to 1,600 r/min or greater. Check that the transaxle is set to the neutral position.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Erase the DTCs using scan tool MB991958.
4. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.)
5. Start the engine.
6. Select "System Test."
7. Select "Evap Leak Mon."
8. During the test, keep the accelerator pedal at the idle position.
9. Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on scan tool MB991958 will change from "NO" to "YES."
10. Turn the ignition switch to the "LOCK" (OFF) position. Disconnect scan tool MB991958.
Q: Is "Evap Leak Mon. Completed. Test Failed and DTCs Set" displayed on scan tool MB991958?
YES: Replace the ECM. Go to Step 21.
NO: If "Evap Leak Mon. Completed. Test Passed" is displayed on scan tool MB991958, the evaporative emission system is working properly at this time. Go to Step 21.
NO: If "Evap Leak Mon. Discontinued. Retest again from the first" is displayed on scan tool MB991958, the EVAP monitor has been interrupted during the test. Turn the ignition switch to the "LOCK" (OFF) position once, and repeat the monitoring from Step 14.
STEP 15. Pressure test for clogging in evaporator line from hoses I to O.
1. Disconnect hose I from the canister side, and plug the hose.
2. Remove the fuel cap.
3. Connect the evaporative emission system pressure pump (Miller number 6872A) to the fuel tank filler tube and apply pressure.
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) manufacture's instructions located in the lid of the pump box.
4. After it is confirmed that pressure maintained, unplug hose I.
5. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
6. Connect hose I to the evaporative emission canister.
Q: Is air blown from hose I?
YES: Go to Step 20.
NO: Go to Step 16.
STEP 16. Check for clogging in the evaporator line hoses I, K, L and M.
1. Remove the fuel tank filler tube protector (Refer to, Fuel Tank).
2. The clogging test with a hand vacuum pump on each hose from hoses I, K, L and M.
Q: Are the hoses in good condition?
YES: Go to Step 17.
NO: Replace the damaged hose, and the fuel tank filler tube protector. Refer to Fuel Tank . Go to Step 21.
STEP 17. Test check valve B.
1. Check valve B is a one-way check valve.
2. Check valve B should allow air to flow in only one direction.
Q: Does check valve B allow air to pass in one direction only?
YES: Go to Step 18.
NO: Replace check valve B, and reinstall the fuel tank filler tube protector. Refer to Fuel Tank. Go to Step 21.
STEP 18. Check for clogging in the evaporator line from hoses J, N and O.
Remove the fuel tank.
Q: Are the hoses in good condition?
YES: Go to Step 19.
NO: Replace the damaged hose, and reinstall the fuel tank. Go to Step 21.
STEP 19. Test check valve C.
1. Check valve C is a one-way check valve.
2. Check valve C should allow air to flow in only one direction.
Q: Does check valve C allow air to pass in one direction only?
YES: Go to Step 21.
NO: Replace check valve C, reinstall the fuel tank and the fuel tank filler tube protector. Go to Step 21.
STEP 20. Check the evaporative emission canister for leaks and clogging.
1. Disconnect hoses G, H and I from the canister side, and connect a hand vacuum pump to the canister instead of hose G, and plug the other nipples.
2. Apply a pressure on the hand vacuum pump, and confirm that air is maintained.
3. Disconnect the hand vacuum pump, and connect hoses G, H and I to the canister.
Q: Is the evaporative emission canister in good condition?
YES: Go to Step 14.
NO: Replace the canister. Refer to Evaporative Emission Canister and Fuel Tank Pressure Relief Valve. Go to Step 21.
STEP 21. Perform the OBD-II drive cycle.
1. Confirm the repair by performing the appropriate drive cycle. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 5. OBD-II Drive Cycle Pattern Lists
2. Read the diagnostic trouble code (DTC).
Q: Is DTC P0455 set?
YES: Return to Step 1.
NO: The procedure is complete.