P0455
DTC P0455: Evaporative Emission Control System Leak Detected (Gross Leak)System Diagram Part 1:
System Diagram Part 2:
TECHNICAL DESCRIPTION
- To judge if there is leak or clog in the fuel system, the ECM
- The ECM
- Then the evaporative emission purge solenoid is driven to set the fuel system into a negative pressure.
- 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 judged as 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
DTC SET CONDITIONS
Logic Flow Charts (Monitor Sequence):
Logic Flow Chart
Test Conditions A: At Start up
- Intake air temperature is 36 °C (97 °F) or less when the engine is started.
- The engine coolant temperature 36 °C (97 °F) or less when the engine is started.
Test Conditions B: For Test to Run
- The engine coolant temperature 60 °C (140 °F) or more
- The engine coolant temperature 20 °C (68 °F) or more
- Engine speed is 1,600 r/min or more.
- Barometric pressure is above 76 kPa (11 psi).
- Volumetric efficiency is between 20 and 70 percent.
- The fuel tank temperature is 36 °C (97 °F) or less.
- Fuel tank differential pressure sensor output voltage 1 - 4 volts.
Test Conditions C: For Test to Stop
- Intake air temperature is less than 5 °C (41 °F).
- When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises higher 451 Pa (0.065 psi)
- When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises higher 324 Pa (0.047 psi)
- 10 seconds have elapsed from the start of the previous monitoring.
- Monitoring time: 136 seconds.
Judgment Criteria
- The fuel tank internal pressure is 2 kPa (0.29 psi) or more after the evaporative emission purge solenoid has been driven when the fuel tank and vapor line were closed.
NOTE: The monitoring time (136 seconds) depends on the fuel level and the temperature in the fuel tank.
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 failed.
- Evaporative emission ventilation solenoid failed.
- Fuel tank differential pressure sensor failed.
- Evaporative emission canister seal is faulty.
- Evaporative emission canister is clogged.
OVERVIEW OF TROUBLESHOOTING
- To determine the cause of DTC P0455, a performance test is needed. The performance test uses a mechanical vacuum gauge and scan tool MB991958mb991958 set on the fuel tank differential pressure sensor (TANK PRES SNER 73.) The mechanical gauge reading is used to verify scan tool MB991958 reading. A comparison of the mechanical gauge reading to scan tool MB991958 reading determines the reading problem in the system.
- Prior to doing the performance test, several simple inspections are needed to exclude some possibilities of the symptom.
DIAGNOSIS
Required Special Tool:
- 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 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.
- With this monitor, 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 the 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," and press the "YES" key.
7. Select "Evap Leak Mon," and press the "YES" key.
8. During the monitor, keep the accelerator pedal at the idling position.
NOTE: If the engine speed does not reach 2,000 r/min during the monitor test, adjustment of the Speed Adjusting Screw may be needed. And adjust to the standard value.
9. Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on the scan tool MB991958 will change from "NO" to "YES."
Q: What is displayed on the scan tool MB991958?
"Evap Leak Mon. Completed Test Passed": The evaporative emission system is working properly at this time. Explain to customer that improperly tightened fuel cap can cause MIL to turn on, and return the vehicle.
"Evap Leak Mon. Completed. Test Failed and DTCs Set": A malfunction has been detected during the monitor test. Go to Step 2.
"Evap Lead Mon. discontinued. Retest again from the first": The monitor was discontinued for a certain reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn the ignition switch to the "LOCK" (OFF) position once, and repeat the monitoring from the Step 1.
STEP 2. Using scan tool MB991958, check solenoid for clogging of the purge control.
1. Disconnect hoses B and C from the evaporative emission purge solenoid side, and connect the hand vacuum pump to the evaporative emission purge solenoid instead of hose C.
2. Set scan tool MB991958 to actuator test mode for item 08: Evaporative Emission Purge Solenoid. When the evaporative emission purge solenoid is operated, apply a pressure on the hand vacuum pump and confirm that air is blown from the other side nipple.
3. Turn the ignition switch to the "LOCK" (OFF) position. Then disconnect scan tool MB991958.
4. Disconnect the hand vacuum pump, and connect hoses B and C to the evaporative emission purge solenoid.
Q: Is the solenoid in good condition?
YES: Go to Step 3.
NO: Replace the evaporative emission purge solenoid. Then go to Step 26.
STEP 3. Check for leaks and clogging in the evaporator line hose A to hose E
Q: Are the hoses in good condition?
YES: Go to Step 4.
NO: Replace the inferior hose. Then go to Step 26.
STEP 4. Check the evaporative emission ventilation solenoid using scan tool MB991958.
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 the hose G from the evaporative emission ventilation solenoid side.
3. Connect the hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hoses have been disconnected.
4. Turn the ignition switch to the "ON" position.
5. Set scan tool MB991958 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.
6. Turn the ignition switch to the "LOCK" (OFF) position. Then disconnect scan tool MB991958.
7. Disconnect the hand vacuum pump, and connect hose G to the evaporative emission canister.
Q: Is the solenoid valve in good condition?
YES: Go to Step 5.
NO: Replace the evaporative emission ventilation solenoid. Then go to Step 26.
STEP 5. Pressure test for leaks in the evaporator line from hose F to hose P.
1. Disconnect hose G from the evaporative emission ventilation solenoid side, and plug the hoses.
2. Remove the fuel cap.
3. Connect the evaporative emission system pressure pump to the fuel filler neck.
4. Apply a pressure on the evaporative emission system pressure pump, and confirm that air is maintained.
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.
5. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
6. Connect hose G to the evaporator line.
Q: Is air maintained?
YES: Go to Step 16.
NO: Go to Step 6.
STEP 6. Pressure test for leaks in the evaporator line from hose I to hose P.
1. Disconnect hose I from the evaporative emission canister side, and plug the hose.
2. Perform the pressure test again.
Q: Is air maintained?
YES: Go to Step 9.
NO: Go to Step 7.
STEP 7. Check for leaks in the evaporator line from hose F to hose H.
1. Remove the fuel tank. (Refer to Fuel Tank)
2. The leakage test with a hand vacuum pump on each hose from hose F to hose H.
Q: Are the hoses in good condition?
YES: Go to Step 8.
NO: Replace the inferior hose, and reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 8. Check for leaks in the evaporative emission canister.
1. Connect a hand vacuum pump to the vent nipple of the evaporative emission canister.
2. Plug the other two nipples or loop a hose between the other nipples.
3. Apply a vacuum with the hand vacuum pump, and confirm that air is maintained.
Q: Is the evaporative emission canister in good condition?
YES: Go to Step 26.
NO: Replace the evaporative emission canister (Refer to Evaporative Emission Canister and Fuel Tank Pressure Relief Valve) and reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 9. Check for leaks in the evaporator line from hose J to hose K.
1. Remove the fuel tank. (Refer to Fuel Tank)
2. Disconnect hose J at the liquid separator side, and then connect a hand vacuum pump to the hose.
3. Plug the hose K at the fuel tank side.
4. Apply vacuum by using the hand vacuum pump, and confirm that the applied vacuum does not fluctuate.
Q: Is air maintained?
YES: Go to Step 10.
NO: Replace the inferior hose, and reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 10. Check for leaks in the evaporator line hose I, L, M, N and O.
1. Remove the fuel tank and fuel filler neck assembly. (Refer to Fuel Tank)
2. The leakage test with a hand vacuum pump on each hose from hose I, L, M, N and O.
Q: Are the hoses in good condition?
YES: Go to Step 11.
NO: Replace the inferior hose, reinstall the fuel tank and fuel filler neck assembly. (Refer to Fuel Tank) Then go to Step 26.
STEP 11. Check the check valve A.
1. Only when you blow the check valve from the direction shown, it should pass air.
2. When you blow the check valve, air should leak from the check valve body.
Q: Is check valve A in good condition?
YES: Go to Step 12.
NO: Replace the check valve A, and reinstall the filler neck assembly. (Refer to Fuel Tank) Then go to Step 26.
STEP 12. Check the check valve B.
1. When you blow the check valve from the arrow direction shown above, it should pass more air.
2. When you blow the check valve from the arrow direction shown below, it should pass less air.
3. When you blow the check valve, air should leak from the check valve body.
Q: Is check valve B in good condition?
YES: Go to Step 13.
NO: Replace the check valve B, and reinstall the filler neck assembly. (Refer to Fuel Tank) Then go to Step 26.
STEP 13. Check for leaks in the evaporator line from hose P.
1. The leakage test with a hand vacuum pump on the hose P.
Q: Is the hose P in good condition?
YES: Go to Step 14.
NO: Replace the hose N, and reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 14. Check for leaks in the fuel tank.
1. Visually check for cracks and leaks, etc.
NOTE: Carefully check the fuel pump assembly and the inner pressure sensor installation section in the fuel tank.
2. Connect an evaporative emission system pressure pump to the leveling valve nipple.
3. 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.
4. Apply pressure with the evaporative emission system pressure pump.
5. In the pressurized state, check for the leak by applying soap water, etc. to each section.
Q: Are there any leaks?
There are leaks at the fuel pump module or the fuel tank differential pressure sensor section. : After reassemble the leaked parts, check again that there are no leaks. Then reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
There are leaks at the fuel tank. : Replace the fuel tank, reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
There are no leaks. : Then go to Step 15.
STEP 15. Visually check for cracks in the fuel tank filler neck.
1. Visually check for cracks in the fuel tank filler neck.
Q: Is the fuel filler neck assembly in good condition?
YES: Reinstall the fuel tank and fuel filler neck assembly. (Refer to Fuel Tank) Then go to Step 26.
NO: Replace the fuel tank filler neck assembly and reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 16. Pressure test for clogging in the evaporator line from hose I to hose P.
1. Disconnect hose I from the evaporative emission canister side, and unplug the hose I.
2. On the EVAP pressure pump, set the pressure/hold valve to OPEN, and set the vent valve to CLOSED. Turn the pump timer to ON. You can reset the timer as required. (These settings are listed under "Leak Test" in the pump instructions.) 3. Air should pass through hose G.
Q: Is air blown from hose I?
YES: Connect the hose I. Then go to Step 17.
NO: Go to Step 21.
STEP17. Pressure test for clogging in the evaporator line from hose F to hose H.
1. Unplug hose G.
2. On the EVAP pressure pump, set the pressure/hold valve to OPEN, and set the vent valve to CLOSED. Turn the pump timer to ON. You can reset the timer as required. (These settings are listed under "Leak Test" in the pump instructions.)
3. Air should pass through hose G.
Q: Is air blown from hose G?
YES: Connect the hose G. Then go to Step 18.
NO: Go to Step 19.
STEP 18. Using scan tool MB991958, check 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.
- With this monitor, 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," and press the "YES" key.
7. Select "Evap Leak Mon," and press the "YES" key.
8. During the monitor, keep the accelerator pedal at the idling position.
NOTE: If the engine speed does not reach 2,000 r/min during the monitor test, adjustment of the Speed Adjusting Screw may be needed. And adjust to the standard value.
9. Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on the scan tool MB991958 will change from "NO" to "YES."
10. Turn the ignition switch to the "LOCK" (OFF) position. Then disconnect scan tool MB991958.
Q: What is displayed on scan tool MB991958?
"Evap Leak Mon. Completed. Test Passed": The evaporative emission system is working properly at this time. Then go to Step 26.
"Evap Leak Mon. Completed. Test Failed and DTCs Set": Replace the ECM
"Evap Lead Mon. discontinued. Retest again from the first": The monitor was discontinued for a certain reason (vehicle speed input from ECM
STEP 19. Check for clogging in the evaporator line hose F to H.
1. Remove the fuel tank. (Refer to Fuel Tank)
2. The clogging test with a hand vacuum pump on each hose from hose F to H.
Q: Are the hoses good condition?
YES: Go to Step 20.
NO: Replace the inferior hose, reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 20. Check for clogging in the evaporative emission canister.
1. Connect a hand vacuum pump to the vent nipple of the evaporative emission canister.
2. Plug the other two nipples or loop a hose between the other nipples.
3. Apply a pressure on the vacuum pump.
4. When each nipple is unplugged, air should pass through the unplugged nipple.
Q: Is the evaporative emission canister in good condition?
YES: Reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
NO: Replace the evaporative emission canister (Refer to Evaporative Emission Canister and Fuel Tank Pressure Relief Valve ) and reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 21. Check for clogging in the evaporator line from hose J to hose K.
1. Remove the fuel tank. (Refer to Fuel Tank)
2. Disconnect hose J at the liquid separator side, and then connect a hand vacuum pump to the hose.
3. Unplug the hose K at the fuel tank side.
4. Apply a pressure on the vacuum pump, air should pass through the hose K.
5.
Q: Are the hoses good condition?
YES: Go to Step 22.
NO: Replace the inferior hose, and reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 22. Check for clogging in the evaporator line hose I, L, M, N and hose O.
1. Remove the filler neck assembly. (Refer to Fuel Tank)
2. The clogging test with a hand vacuum pump on each hose from hoses I, L, M, N and O.
Q: Are the hoses in good condition?
YES: Go to Step 23.
NO: Replace the inferior hose, and reinstall the filler neck assembly. (Refer to Fuel Tank) Then go to Step 26.
STEP 23. Check the check valve A.
1. Only when you blow the check valve from the direction shown, it should pass air.
2. When you blow the check valve, air should leak from the check valve body.
Q: Is check valve A in good condition?
YES: Go to Step 24.
NO: Replace check valve A, and reinstall the filler neck assembly. (Refer to Fuel Tank) Then go to Step 26.
STEP 24. Check the check valve B.
1. When you blow the check valve from the arrow direction shown above, it should pass more air.
2. When you blow the check valve from the arrow direction shown below, it should pass less air.
3. When you blow the check valve, air should leak from the check valve body.
Q: Is check valve B in good condition?
YES: Go to Step 25.
NO: Replace the check valve B, and reinstall the filler neck assembly. (Refer to Fuel Tank) Then go to Step 26.
STEP 25. Check for clogging in the evaporator line from hose N.
1. The clogging test with a hand vacuum pump on the hose N.
Q: Is the hose N in good condition?
YES: Go to Step 26.
NO: Replace the hose N, and reinstall the fuel tank. (Refer to Fuel Tank) Then go to Step 26.
STEP 26. Test 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.
Q: Is diagnostic trouble code P0455 set?
YES: Go to Step 1.
NO: This diagnosis is complete.