P0456

DTC P0456
Similar in operation to the Small Leak test, the Very Small Leak test will detect the presence of a leak that is 0.020 (0.5 mm) or larger in the evaporative system. To prevent a possible misdiagnosis, the Very Small Leak test may use tighter operational limits than required by the Small Leak test. If any of the Very Small Leak test enabling conditions are not met, such as coolant and intake air temperature, the Very Small Leak test will be disabled for the current trip.

DTC DESCRIPTION
Checking tank vacuum from tank pressure sensor under detecting condition, if tank vacuum signals is higher than threshold, PCM sets P0455. And MIL(Malfunction Indication Lamp) turns on.

DTC Detecting Condition:

DTC DETECTING CONDITION

MONITOR SCANTOOL DATA
1. Warm-up engine to normal operating temperature.

NOTE: Evaporative Emissions Systems (EVAP) Leak Tests can be run by the Scan Tool.The tests are automated and provide either a pass-fail result or directions to check for DTCs.

2. Install scan tool and clear DTC




3. Perform "EVAP. LEAKAGE TEST" mode referring to enable conditions as below
4. Monitoring for (pending) DTC by performing " DIAGNOSTIC TROUBLE CODES" or "MONITORING TEST RESULTS". Is the same DTC set?

YES - Go to "System Inspection" procedure.

NO - Fault is intermittent caused by poor contact in sensor`s and/or PCM`s connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection,bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and goto "Verification of vehicle Repair" procedure.

SYSTEM INSPECTION
1. Check vapor hoses for leakage in fuel system.
a. Check vapor hoses between the following components for leakage:
- Intake manifold - Purge control solenoid valve (PCSV)
- Purge control solenoid valve (PCSV) - Canister
- Canister - Canister close valve (CCV)
- Canister - fuel tank

b. Does a leak exist?

YES - Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.

NO - Go to "Check fuel filler pipe for leakage" as below.

2. Check fuel filler pipe for crack or leakage.
a. Check that there is crack or leakage in fuel filler pipe
b. Is there any crack or leakage?

YES - Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.

NO - Go to "Component inspection" procedure.

COMPONENT INSPECTION
1. Check CCV for leakage.
a. Disconnect the hose leading from the CCV to Canister at CCV.
b. Visually Check any tear of the hose leading from the CCV to Canister
c. When the CCV operates, apply a vacuum at the nipple and verify that the CCV holds vacuum.
d. Does a leak exist?

YES - Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

NO - Go to "Check Canister for leakage" as necessary.

2. Check Canister for leakage.
a. Disconnect the hose leading from the CCV to Canister at Canister.
b. When the other nipples are plugged, apply a vacuum at the vent nipple and verify that the Canister holds vacuum
c. Does a leak exist?

YES - Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

NO - Go to "Check fuel tank for leakage" as below.

3. Check fuel tank for leakage.
a. Check fuel tank for crack or leakage.
b. Does a leak exist?

YES - Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

NO - Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.

NOTE: There is a memory reset function on Scantool that can erase optional parts automatically detected and memorized by PCM. After testing PCM on the vehicle, use this function to reuse the PCM on the others

VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness test have been verified as "Complete".
5. Are any DTCs present?

YES - Go to the applicable troubleshooting procedure.

NO - System is performing to specification at this time.