DTC P0455: EVAP System Large Leak Detected; DTC P0456: EVAP System Very Small Leak Detected
Special Tools Required
-Vacuum Pump/Gauge, 0-30 inHg Snap-on YA4000A or equivalent, commercially available
-Vacuum/Pressure Gauge, 0-4 inHg 07JAZ-001000B
The fuel system is designed to allow specified maximum vacuum and pressure conditions. Do not deviate from the vacuum and pressure tests as indicated in these procedures. Excessive pressure/vacuum would damage the EVAP components or cause eventual fuel tank failure.
NOTE:
- Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions SystemsHow to Troubleshoot the CVT System(CVT System) .
- Fresh fuel has a higher volatility that will create greater pressure/vacuum. The best condition for testing is less than a full tank of fresh fuel. If possible, to assist in leak detection, add 1 gallon of fresh fuel to the tank (as long as it will not fill the tank), just before starting these procedures.
| DTC Description | Confirmed DTC | Pending DTC | Freeze Frame |
|---|---|---|---|
| P0455 EVAP System Large Leak Detected | |||
| P0456 EVAP System Very Small Leak Detected |
- 1. Fuel fill cap seal and fuel fill pipe mating surface check:
1. Check the fuel fill cap seal (A) and the fuel fill pipe mating surface (B). Verify that the fuel fill cap tether cord (C) is not caught under the cap.
Is the fuel fill cap seal missing or damaged, is the fuel fill pipe damaged, or is the tether cord caught under the cap?
YES
Replace the fuel fill cap or the fuel fill pipe.
NO
The fuel fill cap and the fuel fill pipe are OK. Go to step 2.
- 2. EVAP canister vent hose check:
1. Remove the left middle floor undercover - Refer to: Middle Floor Undercover Removal and InstallationRear Floor Undercover Removal and InstallationFront Floor Undercover Removal and Installation .
2. Check the EVAP canister vent hose (A) for a blockage or a restriction.
Is there a blockage or a restriction in the hose?
YES
Remove a blockage or a restriction, if needed, replace the EVAP canister vent hose.
NO
Go to step 3.
- 3. Fuel tank vapor recirculation tube visual check:
1. Turn the vehicle to the OFF (LOCK) mode.
2. Check for a poor connection or damage at the fuel tank vapor recirculation tube (A).
Is the tube OK?
YES
The tube is OK. Go to step 4.
NO
Replace the fuel tank vapor recirculation tube, or replace the fuel tank if needed.
- 4. EVAP canister purge valve leak check:
1. Disconnect the vacuum hose (purge line) (A) from the EVAP canister purge valve (B) in the engine compartment, then connect a T-fitting (C), a vacuum gauge, and a vacuum pump/gauge, 0-30 inHg, to the vacuum hose as shown.
2. Slowly apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the hose.
Does it hold vacuum for 1 minute?
YES
Leak not detected at the EVAP canister purge valve. Go to step 5.
NO
- 5. Problem verification:
1. Turn the vehicle to the ON mode.
2. Clear the DTC with the HDS.
3. Select the EVAP TEST in the INSPECTION MENU, then select the FUNCTION TEST with the HDS.
Is the result OK?
YES
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, the EVAP canister vent shut valve, and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot. If the vehicle returns with the same DTC, continue with step 6.
NO
The failure is duplicated. Go to step 6.
- 6. Determine possible failure area (EVAP canister vent shut valve, others):
1. Turn the vehicle to the OFF (LOCK) mode.
2. Disconnect the fuel tank vapor recirculation tube (A) from the EVAP canister (B), and plug the EVAP canister port (C).
3. Remove the T-fitting and vacuum pump/gauge, and connect the vacuum pump/gauge to the vacuum hose (A) as shown.
4. Turn the vehicle to the ON mode.
5. Select the EVAP TEST in the INSPECTION MENU, then select EVAP CVS ON in the SINGLE SOLENOID with the HDS.
6. Apply vacuum to the hose until the FTP reads 1.90 V (-0.59 inHg, -15.1 mmHg).
NOTE: Be careful not to exceed the vacuum. If you do, the FTP sensor can be damaged.
Signal Current conditions Values Unit FTP SENSOR 7. Check the parameter(s) below with the HDS for 1 minute.
Signal Current conditions Values Unit FTP SENSOR Does the voltage increase more than 0.2 V (0.1 inHg, 2.5 mmHg)?
YES
Go to step 7.
NO
Go to step 9.
- 7. EVAP canister vent shut valve operation check:
1. Select the EVAP TEST in the INSPECTION MENU, then select EVAP CVS OFF in the SINGLE SOLENOID with the HDS.
2. Disconnect the EVAP canister vent hose (A) from the EVAP canister vent shut valve port (B), and plug the port.
3. Apply vacuum to the hose until the FTP reads 1.90 V (-0.59 inHg, -15.1 mmHg).
NOTE: Be careful not to exceed the vacuum. If you do, the FTP sensor can be damaged.
Signal Current conditions Values Unit FTP SENSOR 4. Check the parameter(s) below with the HDS for 1 minute.
Signal Current conditions Values Unit FTP SENSOR Does the voltage increase more than 0.2 V (0.1 inHg, 2.5 mmHg)?
YES
The EVAP canister vent shut valve is OK. Go to step 8.
NO
- 8. EVAP canister purge line visual check:
1. Check for a poor connection or damaged EVAP canister purge line between the EVAP canister and the EVAP canister purge valve. Also check for damage to the EVAP canister.
Are the line and the EVAP canister OK?
-
YES
Replace these parts.
- FTP sensor O-ring
- EVAP canister vent shut valve case and O-ring
- EVAP canister
NO
Replace or repair the EVAP canister purge line or the canister.
-
- 9. Fuel fill pipe and fuel vapor return pipe visual check:
1. Select EVAP CVS OFF in the SINGLE SOLENOID with the HDS.
2. Check for a poor connection or damage to the fuel fill pipe and the fuel vapor return pipe.
Are the parts and connections OK?
YES
The fuel fill pipe and the fuel vapor return pipe are OK. Check the fuel tank unit base gasket and the fuel tank.
NO
Repair or replace the damaged parts.