Hummer P0456 EVAP System Small Leak

Description

OBD-II Trouble Code Description for P0456 Hummer

Evaporative Emission System Leak Detected (very small leak)

What does this mean?

OBD2 Code P0456 Hummer definition:
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 (FTP) sensor. When the sensor indicates a small leak in the EVAP system, this code is set.

Symptoms

Possible sumptoms of OBD code P0456 Hummer
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.

Causes

Possible causes of OBD code P0456 Hummer
Usually this P0456 Hummer 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

Possible Solutions

First, using a scan tool activate the vent solenoid, sealing the system. Then monitor the fuel tank pressure (FTP) sensor. If the system is sealing properly, the number will stay consistent. If is isn’t, the pressure sensor will show that as well. If the system slowly leaks, use a smoke machine and watch for smoke exiting the system at any EVAP component. Any where there is smoke exiting the system, that is the faulty component. Do not pressurize the EVAP system with air pressure. Doing so can damage the purge and vent solenoids in the system.

Related Codes

P0440 Hummer P0441 Hummer P0442 Hummer P0443 Hummer P0446 Hummer P0453 Hummer P0455 Hummer P0456 Hummer


The OBD2 Code Information Be Applicable For Hummer:

2009 Hummer H3T Alpha,2008 Hummer HX Concept,2008 Hummer H3 Wagon Concept,2008 Hummer H3 Alpha,2008 Hummer H2,2007 Hummer H3 Open Top,2007 Hummer H3X,2007 Hummer H3R Off Road Concept,2007 Hummer H2 Safari Concept,2006 Hummer H3,2006 Hummer H2 SUT Limited Edition,2006 Hummer H1 Alpha,2005 Hummer H3 Street,2005 Hummer H2 SUT,2004 Hummer H2 SUT Concept,2004 Hummer H2H Hydrogen Concept,2004 Hummer H2,2004 Hummer H1,2003 Hummer Humvee Military Vehicle,2003 Hummer H3T Concept,2003 Hummer H2 with GM Accessories,2003 Hummer H2 SUV,2003 Hummer H2 SUT Dirt Sport Concept,2003 Hummer H1,2003 Hummer Bike,2002 Hummer H2 SUV Concept,2002 Hummer H1 10th Anniversary Edition,2002 Hummer H1,2001 Hummer H1 Alpha Concept

 

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