P0455
DTC P0455: Evaporative Emission Control 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
- The ECM
- 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
- 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 Chart:
LOGIC FLOW CHARTS (Monitor Sequence)
DTC SET CONDITIONS
Check Conditions A: At Start up
- Intake air temperature is 36 °C (97 °F) or less upon engine start up.
- The engine coolant temperature is 36 °C (97 °F) or less upon engine start up.
Check Conditions B: For Test to Run
- The engine coolant temperature is 60 °C (140 °F) or greater and the fuel tank is 15 - 40 percent full.
- The engine coolant temperature is 20 °C (68 °F) or greater and the fuel tank is 40 - 85 percent full.
- 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 80 percent.
- The fuel temperature is 36 °C (97 °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 °C (41 °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 Criteria
- The fuel tank internal pressure is 2kPa (0.29 psi) or more after the evaporative emission purge solenoid valve 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 - Procedure 1 - Evaporative Emission System Leak Monitor. 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 (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B
STEP 1. Using scan tool MB991958, check the EVAP 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
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, then go to Step 2.
NO <"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 illuminate. Return the vehicle to the customer.
NO <"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 B and C from the evaporative emission purge solenoid valve side, and connect the hand vacuum pump to the evaporative emission purge solenoid valve instead of hose C.
3. Turn the ignition switch to the "ON" position.
4. Set scan tool MB991958 to actuator test mode.
- 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 B and C 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 19.
STEP 3. Check for leaks and clogging in evaporative emission hoses A through C.
Q: Are the hoses in good condition?
YES: Go to Step 4.
NO: Replace the damaged hose. Go to Step 19.
STEP 4. Using scan tool MB991502, check date list item 29: Evaporative emission ventilation solenoid.
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 F from the evaporative emission Ventilation solenoid.
3. Connect a hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hose was disconnected.
4. Turn the ignition switch to the "ON" position.
5. Set scan tool MB991958 to actuator test mode.
- Item 29: Evaporative Emission Ventilation Solenoid.
- While the evaporative emission ventilation solenoid is activated, operate the hand vacuum pump and confirm that the solenoid holds vacuum.
6. Turn the ignition switch to the "LOCK" (OFF) position and disconnect scan tool MB991958.
7. Disconnect the hand vacuum pump, and connect hose F to the evaporative emission ventilation solenoid.
Q: Did the evaporative emission ventilation solenoid hold vacuum?
YES: Go to Step 5.
NO: Replace the evaporative emission ventilation solenoid (Refer to Evaporative Emission Canister and Fuel Tank Pressure Relief Valve). Then go to Step 19.
STEP 5. Check for leaks and clogging in the evaporative emission hose F.
Perform a vacuum test using a hand vacuum pump on hose F.
Q: Is the hose in good condition?
YES: Go to Step 6.
NO: Replace the damaged hose. Go to Step 19.
STEP 6. Check for leaks and clogging in evaporative emission hoses D through E.
Perform a vacuum test using a hand vacuum pump on hoses D through E.
Q: Are the hoses in good condition?
YES: Go to Step 7.
NO: Replace the damaged hose. Go to Step 19.
STEP 7. Pressure test for leaks in evaporative system lines from hose G through the fuel tank to hose Q.
1. Disconnect hose G from the canister, and plug hose G 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. Connect the evaporative emission system pressure pump to the fuel filler neck.
4. 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.
5. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
6. Connect hose G to the canister.
Q: Is the evaporative emission line free of leaks?
YES: Go to Step 13.
NO: Go to Step 8.
STEP 8. Check for vacuum leaks in evaporative emission system hoses G, I, J and K.
1. Remove the fuel filler neck protector (Refer to Fuel Tank).
2. Perform a leakage test with a hand vacuum pump on each hose from hoses G, I, J and K.
Q: Do the hoses hold vacuum?
YES: Go to Step 9.
NO: Replace the damaged hose, and reinstall the fuel filler neck protector (Refer to Fuel Tank). Go to Step 19.
STEP 9. 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 10.
NO: Replace check valve A, and reinstall the fuel filler neck protector (Refer to Fuel Tank). Go to Step 19.
STEP 10. Check for leaks in evaporative emission hoses H, L, M, N, 0, P and Q.
1. Remove the fuel tank (Refer to Fuel Tank).
2. Perform a leakage test with a hand vacuum pump on each hose H, L, M, N, 0, P and Q.
Q: Do the hoses hold vacuum?
YES: Go to Step 11.
NO: Replace the damaged hose, and reinstall the fuel tank (Refer to Fuel Tank). Then go to Step 19.
STEP 11. 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 12
NO: Replace check valve B, and reinstall the fuel tank and the fuel filler neck protector (Refer to Fuel Tank). Then go to Step 19
STEP 12. 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 the evaporative emission system pressure pump (Miller number 6872A) to the filler hose.
3. Plug the fuel pump feed nipple, hose H, hose L and hose Q connected to the fuel tank.
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: Is any leaks found?
YES
YES
NO: When there is no leak, reinstall the fuel tank (Refer to Fuel Tank). Then go to Step 18.
STEP 13. Check the evaporative emission canister for leaks and clogging.
1. Disconnect hoses E, F and G from the canister side, and connect a hand vacuum pump to the canister instead of hose E, 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 E, F and G 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). Then go to Step 19.
STEP 14. Check for clogging in the evaporator line hoses G, I, J and K.
1. Remove the fuel filler neck protector (Refer to Fuel Tank).
2. The clogging test with a hand vacuum pump on each hose from hoses G, I, J and K.
Q: Are the hoses in good condition?
YES: Go to Step 15.
NO: Replace the damaged hose, and the fuel filler neck protector (Refer to Fuel Tank). Then go to Step 19.
STEP 15. 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 16.
NO: Replace check valve A, and reinstall the fuel filler neck protector (Refer to Fuel Tank). Then go to Step 19.
STEP 16. Check for clogging in the evaporator line from hoses H, L, M, N, 0, P and Q.
Remove the fuel tank (Refer to Fuel Tank).
Q: Are the hoses in good condition?
YES: Go to Step 17.
NO: Replace the damaged hose, and reinstall the fuel tank (Refer to Fuel Tank). Then go to Step 19.
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: Reinstall the fuel tank (Refer to Fuel Tank). Then go to Step 18.
NO: Replace check valve B, reinstall the fuel tank and the fuel filler neck protector (Refer to Fuel Tank). Then go to Step 19.
STEP 18. Using scan tool MB991958, check the EVAP 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
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
NO <"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 19.
NO <"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 18.
STEP 19. Perform the OBD-II drive cycle.
1. Confirm the repair by performing the appropriate drive cycle (Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 1 - Evaporative Emission System Leak Monitor). OBD-II Drive Cycle Pattern Lists
2. Read the diagnostic trouble code (DTC).
Q: Is DTC P0455 set?
YES: Repeat the troubleshooting from Step 1.
NO: The procedure is complete.