Description
OBD-II Trouble Code Description for P0400 Hummer
Exhaust Gas Recirculation Flow
What does this mean?
OBD2 Code P0400 Hummer definition:
The exhaust gas recirculation (EGR) valve is vacuum controlled valve that regulates the amount of exhaust gases that re-enter the cylinders. The powertrain control module (PCM) determines how much based on engine load, temp, and other conditions. If the PCM detects that the amount of exhaust gases entering the cylinder were insufficient or non-existent, this code is set.
Symptoms
Possible sumptoms of OBD code P0400 Hummer
No symptoms will likely be noticed by the driver other than the MIL (malfunction indicator lamp). However, non visible symptoms will be increased combustion temperature and increased Nox emissions. Sometimes you may notice a flat spot, or the vehicle may enter limp mode or show a EML light.
Causes
Possible causes of OBD code P0400 Hummer
A code P0400 Hummer may mean that one or more of the following has happened: Plugged EGR passage which restricts the flow of exhaust gasses Faulty EGR solenoid Faulty EGR solenoid wiring/harness Vacuum lines damaged/disconnected to the EGR valve solenoid or to the EGR valve Faulty EGR valve
Possible Solutions
Since EGR valve designs are different, no one test will suffice: Using a scan tool, operate the EGR valve with the engine running. If the engine stumbles, the problem was likely intermittent wiring problem or intermittent blockage problem If engine doesn’t stumble, operate the EGR valve manually, if possible. If engine doesn’t stumble and die, the ports are likely plugged. Removal of valve and cleaning of all ports will be required Checking of solenoid can only usually be done with a scan tool, because most solenoids operate with a duty cycle of voltage, rather than constant voltage Check all vacuum lines, hoses, etc for any damage Visually inspect the solenoid harness and the solenoid for damage Replace EGR valve
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
Note:
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