Join Date: Jun 2006
Own a Commander?: Yes
Model year: 2006
Trim Package: Limited
Power-Train: 5.7L V-8 Hemi
If 4WD - system: QD-II
Code P0456 = Evaporative Emissions System - Small leak detected
My CEL (check engine light) came on this past Monday and I checked for codes with the three key turns method and got P0456. When I looked it up it said:
Evaporative Emissions System - Small leak detected
What does that mean?
The Powertrain Control Module (PCM) at different times performs various tests on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank vapors from venting into the atmosphere, and instead purges them into the engine to be burned. Regular pressure tests are conducted by the PCM to monitor the sealed system for leaks. The PCM monitors the EVAP system pressure by watching the Fuel tank pressure sensor (FTP). When the sensor indicates a small leak in the EVAP system, this code is set.
There will likely be no noticeable symptoms other than the Malfunction Indicator Lamp (MIL). This is because the EVAP system is a closed system and only controls fuel tank vapors, not engine management.
Usually this P0456 code is caused by an incorrect or faulty gas cap
. Filling the fuel tank with the engine running could conceivable cause this code as well or if the cap wasn't properly tightened. Any of the following could also be the cause:
- A small leak in any of the EVAP hoses or fuel tank hoses
- A small leak in the purge valve or vent valve
- The EVAP Canister may be leaking
So I checked the gas cap and still got the code and the CEL has been on all week. I filled up my tank today and the CEL went out. ????????
2006 Steel Blue 5.7L HEMI Limited 4x4 Build Date: June 9, 2006 Hour 14
Interior: Dark Slate/Light Graystone with Saddle Brown Leather Seats
Quadra-Drive II, NAV, DVD, Trailer Tow Group IV, Off-Road Group II, Remote Start, UConnect, Rear Backup Camera, Chrome Wheels,
Magnaflow cat-back exhaust, Daytime Running Lights enabled, 2" Rough Country Lift with 265/70R17 Goodyear Wrangler AT/S
Last edited by jeep5253; 03-07-2009 at 07:06 PM.