DTC P0456
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 .
- 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 |
|---|---|---|
| P0456 EVAP System Very Small Leak Detected |
DTC (PGM-FI)
- Problem verification
-1. Turn the vehicle to the ON mode.
-2. Clear the DTC with the HDS.
-3. Select the EVAP TEST in the Function Test Menu, then select EVAP Leak Check Module Test with the HDS.
EVAP TEST
Is the result OK?
YES
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EVAP leak check module, the EVAP canister purge valve(s), and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot . If the vehicle returns with the same DTC, continue with step 2.
NO
The failure is duplicated. Go to step 2.
- EVAP canister drain hose check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove the heat shield .
-3. Check the EVAP canister drain 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 drain hose A.
NO
Reconnect the hose, then go to step 3.
- EVAP leak check module drain hose check
-1. Check the blockage in the hoses and the EVAP canister filter .
Are the parts OK?
YES
Go to step 4.
NO
Remove the blockage from them, or replace the part(s) if needed.
- EVAP canister purge valve leak check
-1. Disconnect the vacuum hose (purge line) (A) from the 3-way joint (B) in the engine compartment, then connect the T-fitting (C), the vacuum gauge, and the vacuum pump/gauge, 0-30 inHg as shown.
-2. Slowly apply about 2 kPa (15 mmHg, 0.6 inHg) of vacuum to the hose.
Does it hold vacuum for 1 minute?
YES
Leak is not detected between the 3-way joint and EVAP canister purge valves. Go to step 5.
NO
Go to step 10.
- Determine possible failure area (EVAP canister, others)
-1. Disconnect the fuel vent tube (A) from the EVAP canister (B), and plug the EVAP canister port (C).
-2. Disconnect the vacuum gauge, the tube joint adapter, and the vacuum pump/gauge from the hose.
-3. Connect the vacuum pump/gauge, 0-30 inHg to the hose as shown.
-4. Turn the vehicle to the ON mode.
-5. Select the EVAP TEST in the Function Test Menu, then select CCV ON in the Single Solenoid Test with the HDS.
EVAP TEST
Apply vacuum to the hose until the Absolute Pressure of ELCM Pressure Sensor is 2 kPa (15 mmHg, 0.6 inHg).
NOTE: Be careful not to exceed the vacuum. If you do, the EVAP leak check module can be damaged.
Signal Current conditions Values Unit Absolute Pressure of ELCM Pressure Sensor -7. Check the parameter(s) below with the HDS for 1 minute.
Signal Current conditions Values Unit Absolute Pressure of ELCM Pressure Sensor Does it hold a vacuum?
YES
Go to step 7.
NO
Go to step 6.
- EVAP canister check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the EVAP canister drain hose A from the EVAP canister port (B), and plug it.
-3. Connect the T-fitting (A), the vacuum gauge, and the vacuum pump/gauge, 0-30 inHg as shown, then slow apply about 2 kPa (15 mmHg, 0.6 inHg) of vacuum to the hose.
Does it hold vacuum?
YES
The EVAP canister is OK. Replace the EVAP leak check module .
NO
Check for a poor connection or damage to the EVAP purge line between the 3-way joint and the EVAP canister, then replace the EVAP canister .
- Fuel fill pipe and fuel tank vapor recirculation tube visual check
-1. Check for a poor connection or damage to the fuel fill pipe and the fuel tank vapor recirculation tube.
Are the parts and connections OK?
YES
The fuel fill pipe and fuel tank vapor recirculation tube are OK. Go to step 8.
NO
- Shut-off valve check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Check the flap of the shut-off valve (A).
Is the flap closed?
YES
Go to step 9.
NO
- Shut-off valve seal check
-1. Check the flap seal of the shut-off valve (A) and the mating surface.
Is the flap seal missing or damaged, is the shut-off valve mating surface damaged?
YES
NO
The shut-off valve is OK. Check the fuel tank unit base gasket and fuel tank.
- EVAP canister purge valve 1 leak check
-1. Remove the vacuum gauge, the tube joint adapter, and the vacuum pump/gauge from the 3-way joint, then reconnect the hose.
-2. Disconnect the hose (A) of EVAP canister purge valve 1 (B) from the intake manifold (C), then connect the T-fitting (D), the vacuum gauge, and the vacuum pump/gauge, 0-30 inHg as shown.
-3. Slowly apply about 2 kPa (15 mmHg, 0.6 inHg) of vacuum to the hose.
Does it hold vacuum for 1 minute?
YES
Leak is not detected at EVAP canister purge valve 1. Go to step 11.
NO
- EVAP canister purge valve 2 leak check
-1. Remove the vacuum gauge, the tube joint adapter, and the vacuum pump/gauge from EVAP canister purge valve 1, then reconnect the hose.
-2. Disconnect the hose (A) of EVAP canister purge valve 2 (B) from the throttle body (C), then connect the T-fitting (D), the vacuum gauge, and the vacuum pump/gauge, 0-30 inHg as shown.
-3. Slowly apply about 2 kPa (15 mmHg, 0.6 inHg) of vacuum to the hose.
Does it hold vacuum for 1 minute?
YES
Leak is not detected at EVAP canister purge valve 2. Check for a leakage at the 3-way joint and the hoses between the 3-way joint and each EVAP canister purge valve.
NO