P0456-EVAP SYSTEM SMALL LEAK
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the ignition off, fuel level less than 88%, ambient temperature between 4° C and 43° C (39° F and 109° F).
- Set Condition:
As temperatures change, a vacuum is created in the fuel tank and EVAP system. With the EVAP system sealed, the PCM monitors the ESM switch. If the ESM switch does not close within a calibrated time, an error is detected by the PCM. One Trip Fault. Three good trips to turn off the MIL.
| Possible Causes |
| INTERMITTENT DTC |
| EVAP PURGE SOLENOID VACUUM SUPPLY |
| EVAP PURGE HOSE/TUBE OBSTRUCTION |
| EVAP SYSTEM LEAK |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
1. EVAP SYSTEM INSPECTION
Inspect the Evap System for any of the following conditions:
- Holes or cracks
- Loose seal points
- Damaged or missing components
- Incorrect routing of hoses and tubes
- Loose or missing fuel cap
- Damaged or missing fuel cap seal
- Improper installation of the fuel cap
- Damaged locking tabs on the fuel cap and/or filler tube
- Damaged seal points on the fuel cap and/or filler tube
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go to 2
2. EVAP PURGE SOLENOID
Disconnect the purge lines at the Evap Purge Solenoid.
Using a hand vacuum pump, apply 10 inHg of vacuum to the "CAN" side of the Evap Purge Solenoid.
NOTE: The solenoid should hold vacuum for a minimum of 15 seconds.
Turn the ignition on.
With the scan tool, actuate the Evap Purge Solenoid to the ON position.
NOTE: The vacuum should drop when the solenoid is actuated.
Does the solenoid function as described above?
Yes
- Go to 3
No
- Replace the Evap Purge Solenoid.
- Perform the PCM Verification Test. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
3. EVAP PURGE HOSE/TUBE OBSTRUCTION
Inspect the Evap Purge hose/tube between the Evap Purge Solenoid and the Fuel Tank and between the Fuel Tank and the Evap Purge Canister for proper routing and installation.
Make sure the hoses and tubes are not damaged, kinked, or blocked.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the PCM Verification Test. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go to 4
4. CHECKING THE EVAPORATIVE SYSTEM FOR LEAKS
Perform the diagnostic procedure for *CHECKING THE EVAPORATIVE SYSTEM FOR LEAKS.
Were any problems found?
Yes
- Repair as necessary in accordance with the Service Information.
- Perform the PCM Verification Test. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)