P0455
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.
DTC SET CONDITIONS
Test Conditions A: At Start up
- Intake air temperature is 30 °C (86 °F) or less when the engine is started.
- The engine coolant temperature is 30 °C (86 °F) or less when the engine is started.
Test Conditions B: For Test to Run
- With in 16 minutes after the engine is started.
- Engine coolant temperature is higher than 60 °C (140 °F).
- Engine speed is 1,600 r/min or more.
- Power steering pressure switch: "OFF."
- Barometric pressure is above 76 kPa (11 psi).
- Volumetric efficiency is between 25 and 80 percent.
- Vehicle speed is 30 km/h (18.7 mph) or more.
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 to 451 Pa (0.065 psi).
- The pressure fluctuation width is less than 647 Pa (0.094 psi).
- Fuel tank differential pressure sensor output voltage 1 - 4 V.
Judgment Criteria
- The fluctuation of fuel tank internal pressure is less than 324 Pa (0.047 psi) in 20 seconds after the evaporative emission purge solenoid had been driven when the fuel tank and vapor line were closed.
NOTE: The monitoring time (75 - 125 seconds.) depends on the fuel level and the temperature in the fuel tank.
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 MB991502 set on the fuel tank differential pressure sensor (TANK PRES SNER 73). The mechanical gauge reading is used to verify scan tool MB991502 reading. A comparison of the mechanical gauge reading to the scan tool MB991502 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:
MB991502: Scan Tool (MUT-II)
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
In this procedure, scan tool MB991502 should be used in the metric mode (showing the value in kPa). If not, set scan tool MB991502 by selecting the "System Setup" at the main menu.
STEP 1. Check for leaks in the evaporator line hose A and evaporative emission purge solenoid valve.
1. Disconnect hose A at the intake manifold side, and then connect a hand vacuum pump to the hose.
2. Apply vacuum.
NOTE: The vacuum should be 40 kPa (5.8 psi) or less.
Q: Is the vacuum maintained?
YES: Go to Step 4.
NO: Go to Step 2.
STEP 2. Check for leaks in the evaporator line hose A.
1. The leakage test with a hand vacuum pump on hose A.
Q: Are there any leaks?
YES: Replace that hose. Then go to Step 30.
NO: Go to Step 3.
STEP 3. Check the evaporative emission purge solenoid valve using the scan tool MB991502. (Actuator test item 08)
1. Turn the ignition switch to the "ON" position.
2. Connect the hand vacuum pump to the nipple of the evaporative emission purge solenoid from which the hoses have been disconnected.
3. Apply a vacuum on the hand vacuum pump, and confirm that the applied vacuum does not fluctuate.
If the vacuum fluctuates, refer to diagnosis step for evaporative emission purge solenoid trouble code DTC P0443.
4. While maintaining the vacuum, carry out the actuator test with scan tool MB991502.
Q: Does the vacuum pump gauge indicate the atmospheric pressure when the evaporative emission purge solenoid is activated?
The evaporative emission purge solenoid valve operates normally, and the vacuum pump gauge reading returns to the atmospheric pressure: Go to Step 30.
The evaporative emission purge solenoid valve operates normally, but the vacuum pump gauge does not indicate the atmospheric pressure: Replace the evaporative emission purge solenoid. Then go to Step 30.
The evaporative emission purge solenoid valve does not operate normally: Refer to diagnosis step for evaporative emission purge solenoid trouble code DTC P0443.
STEP 4. Check for leaks in the evaporator line hose A and evaporative emission purge solenoid valve.
1. Use scan tool MB991502 to activate the evaporative emission purge solenoid valve.
Q: Does the vacuum leak?
YES: Go to Step 6.
NO: Go to Step 5.
STEP 5. Check for clogging in the evaporator line hose A.
1. Sequentially apply vacuum with a hand vacuum pump connected to hose A.
Q: Are there any clogs?
YES: Replace that hose, and perform the purge flow check. (Refer to Engine Emission Control - Evaporative Emission Control System - Purge Control System Check.)
NO: Go to Step3.
STEP 6. Check the evaporative emission ventilation solenoid using the scan tool MB991502. (Actuator test item 29)
1. Turn the ignition switch to the "ON" position, remove the module bracket mounting volts and disconnect hose G from the evaporative emission ventilation solenoid side.
2. Connect the hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hoses have been disconnected.
3. Apply a vacuum on the hand vacuum pump, and confirm that pressure is applied.
If the vacuum is maintained, refer to evaporative emission ventilation solenoid trouble code DTC P0446.
4. Drive the evaporative emission ventilation solenoid with the scan tool MB991502 actuator test, and confirm that the vacuum does not fluctuate when the vacuum is applied with the hand vacuum pump.
Q: Does the vacuum pump gauge reading return to the atmospheric pressure when the evaporative emission ventilation solenoid valve is activated?
The evaporative emission ventilation solenoid valve operates normally and the vacuum pump gauge reading does not fluctuate: Go to Step 7.
The evaporative emission ventilation solenoid valve operates normally, but the vacuum can not be maintained: replace the evaporative emission ventilation solenoid. Then go to Step 30.
The evaporative emission ventilation solenoid valve does not operate normally: Refer to diagnosis step for evaporative emission ventilation solenoid trouble code DTC P0446.
STEP 7. Pressure test for evaporator line from hose C to hose P.
1. Disconnect hose G from the filler neck assembly side, and plug the hoses from which the hoses have been disconnected.
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 an evaporative emission system pressure pump to the fuel filler neck.
4. Pressure test the system to determine whether any leaks are present.
NOTE: "Pressure test" in this procedure refers to the 1/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.
Q: Are there any leaks in the evaporator line?
YES: Go to Step 8.
NO: Go to Step 20.
STEP 8. Pressure test for evaporator line from hose I to hose P.
1. Disconnect hose I from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected.
2. Perform the pressure test again.
Q: Is the pressure maintained inside the evaporator line?
YES: Go to Step 9.
NO: Go to Step 12.
STEP 9. Check for leaks in the evaporator line hose C to hose E.
1. The leakage test with a hand vacuum pump on each hose from hose C.
Q: Can the leaks be pinpointed?
YES: Replace that hose. Then go to step 30.
NO: Go to step 10.
STEP 10. Check for leaks in the evaporator line from hose F to hose H.
1. Remove the fuel tank.
2. The leakage test with a hand vacuum pump on each hose from hose F to hose H.
Q: Can the leaks be pinpointed?
YES: Replace that hose, reinstall the fuel tank. Then go to Step 30.
NO: Go to step 11.
STEP 11. 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 the applied vacuum does not fluctuate.
Q: Does the vacuum pump gauge reading fluctuate?
YES: Replace the evaporative emission canister, and reinstall the fuel tank. Then go to Step 30.
NO: Reinstall the fuel tank, then go to Step 30.
STEP 12. Check for leaks in the evaporator line hose I, L, M, N and hose O.
1. Remove the filler neck assembly.
2. Sequentially apply vacuum with a hand vacuum pump connected to hose I, L, M, N and hose O.
Q: Can the leaks be pinpointed?
YES: Replace that hose, reinstall the filler neck assembly. Then go to Step 30.
NO: Go to Step 13.
STEP 13. 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, on air should leak from the check valve body.
Q: Is there any failure?
YES: Replace it, reinstall the filler neck assembly. Then go to Step 30.
NO: Go to Step 14.
STEP 14. 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, on air should leak from the check valve body.
Q: Is there any failure?
YES: Replace it, reinstall the filler neck assembly and filler neck protector. Then go to Step 30.
NO: Go to Step 15.
STEP 15. Check for leaks in the evaporator line from hose J to hose K.
1. Disconnect hose J at the liquid separator side, and then connect a hand vacuum pump to the hose.
2. Disconnect hose K at the fuel tank side, and then plug the hose.
3. Apply vacuum by using the hand vacuum pump.
Q: Is the vacuum maintained inside the evaporator line?
YES: Go to Step 16.
NO: Go to Step 19.
STEP 16. Check for leaks in the evaporator line from hose P.
1. Remove the fuel tank.
2. The leakage test with a hand vacuum pump on each hose from hose P.
Q: Can the leaks be pinpointed?
YES: Replace that hose. Then go to Step 17.
NO: Go to Step30.
STEP 17. 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: Can the leaks be pinpointed?
There is leaks at the fuel pump assembly or the inner pressure sensor installation section: Reassemble the parts, check again that there are no leaks, reinstall the fuel tank. Then go to Step 30.
There is leaks at another section: Go to Step 18.
STEP 18. Visually check for cracks in the fuel tank filler neck.
1. Visually check for cracks in the fuel tank filler neck.
Q: Can the leaks be found out?
YES: Replace the fuel tank filler neck assembly and reinstall the fuel tank. Then go to Step 30.
NO: Reinstall the fuel tank. Then go to Step 30.
STEP 19. Check for leaks in the evaporator line from hose J to hose K.
1. The leakage test with a hand vacuum pump on each hose from hose J to hose K.
Q: Can the leaks be pin pointed?
YES: Replace that hose, and go to Step 30.
NO: Go to Step 30.
STEP 20. Check for clogging in the evaporator line from hose G to hose I.
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: Does air pass through hose G?
YES: Go to Step 30.
NO: Go to Step 21.
STEP 21. Check for clogging in the evaporator line hose I.
1. The clogging lest with a hand vacuum pump on each hose from hose I.
Q: Are there any clogs?
YES: Replace that hose, and perform the OBD-II drive cycle.
NO: Go to Step 22.
STEP 22. Check for clogging in the evaporator line from hose H
1. Remove the fuel tank.
2. The clogging lest with a hand vacuum pump on each hose from hose H.
Q: Are there any clogs?
YES: Replace that hose, and perform the OBD-II drive cycle.
NO: Go to Step 23.
STEP 23. 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 vacuum, when each nipple is unplugged, the vacuum should fluctuate.
Q: Does the vacuum pump gauge reading fluctuate?
YES: Reinstall the fuel tank. Then perform the OBD-II drive cycle.
NO: Replace the evaporative emission canister, reinstall the fuel tank. Then perform the OBD-II drive cycle.
STEP 24. Check for clogging in the evaporator line hose F.
1. Disconnect hose F at the intake manifold side, and then connect a hand vacuum pump to hose F at the floor pipe side.
2. Apply vacuum.
NOTE: The vacuum should be 40 kPa (5.8 psi) or less.
3. Use scan tool MB991502 to activate the evaporative emission purge solenoid valve. The vacuum should leak.
Q: Is the vacuum maintained inside the evaporator line?
YES: Go to Step 25.
NO: Go to Step 26.
STEP 25. Check for clogging in the evaporator line hose C to hose E.
1. The clogging test with a hand vacuum pump on each hose from hose C to hose E.
Q: Are there any clogs?
YES: Replace that hose, and perform the purge flow check. (Refer to Purge Control System Check.)
NO: Perform the OBD-II drive cycle.)
STEP 26. Check for clogging in the evaporator line hose L and hose O.
1. Remove the filler neck assembly.
2. The clogging test with a hand vacuum pump on each hose from hose L and hose O.
Q: Are there any clogs?
YES: Replace that hose, reinstall the filler neck assembly and filler neck protector, and perform the OBD-II drive cycle.
NO: Go to Step 27.
STEP 27. 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, on air should leak from the check valve body.
Q: Is there any failure?
YES: Replace it, then perform the OBD-II drive cycle.
NO: Go to Step 28.
STEP 28. 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, on air should leak from the check valve body.
Q: Is there any failure?
YES: Replace it, then perform the OBD-II drive cycle.
NO: Go to Step 29.
STEP 29. Check for clogging in the evaporator line from hose F and hose P.
1. Remove the filler neck assembly. (Refer to Fuel tank.)
2. Carry out the clogging test with a hand vacuum pump on each hose from hose F and hose P.
Q: Are there any clogs?
YES: Replace that hose, reinstall the fuel tank, and perform the OBD-II drive cycle.
NO: Reinstall the fuel tank. Then perform the OBD-II drive cycle.
STEP 30. Evaporative Emission System Monitor Test using scan tool MB991502.
1. Turn the ignition switch to the "ON" position.
2. Erase the DTCs using the scan tool MB991502.
3. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.)
4. Start the engine.
5. Select "System Test," and press the "YES" key.
6. Select "Evap Leak Mon," and press the YES" key.
7. 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. Refer to Basic Speed Idle Adjustment and adjust to the standard value.
8. Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on the scan tool MB991502 will change from "NO" to "YES."
Q: What kind of message is displayed on scan tool MB991502?
When the message "Evap Leak Mon. Completed. Test Passed" is displayed: 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.
When the message "Evap Leak Mon. Completed. Test Failed and DTCs Set" is displayed: Go to Step 1.
When the message "Evap Lead Mon. discontinued. Retest again from the first" is displayed: Turn the ignition switch to the "LOCK" (OFF) position once, then repeat this monitor test from the start.