My 2004 Chevy Trailblazer
4.L inline 6 cyl
Codes p0455
tech = any
question = what should i be looking for when code p0455 comes
up....evaporative emission control  system leak detected (gross leak)
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JK:
Answer: Code p0455 is a large EVAP leak.
A common cause for this is a loose or faulty gas cap. Or if the truck was running
when you were filling it with gas, this can also cause this code.
Another common cause is a faulty / sticking EVAP vent solenoid / valve. If the
vent  valve does not operate, the system will not seal when it needs to, thus
causing a large leak. A simple test with a test light and a scanner that can turn
the vent solenoid on and off would need to be done to test the valve.
Problem with my 2002 Chevy Trailblazer
New times put on within 2,000 miles ; car inspected December 2009
Question: DRIVING AT 45 MPH AND ABOVE I HEAR A HIGH PITCH HUM FROM REAR PASSENGER WHEEL.
THERE ARE NO VIBRATIONS WHATSOEVER. VEHICLE RECENTLY PASSED INSPECTION 12/09.
GM Tech JK:
Answer: Try popping it into neutral as the noise is occurring. Be sure to let off the gas.
This will tell you if it is related to vehicle speed, or engine speed. If the noise continues
the same, you may have a noisy bearing in the rear differential. If the sound changes,
then it is an engine frequency noise. Possibly exhaust heat shield, exhaust hitting
frame, rear end housing or suspension component.
Trailblazer Check Engine Light P0455
Large Leak
The evaporative emission (EVAP) control system limits the fuel vapors from escaping into the atmosphere. The EVAP
transfers the fuel vapors from the sealed fuel tank to an activated carbon storage device, the EVAP canister. The EVAP
canister stores the vapors until the engine is able to use the extra fuel vapor. When the engine is able to use the extra fuel
vapor, the intake air flow purges the fuel vapor from the carbon element and then the normal combustion process
consumes the fuel vapor. The system is required in order to detect the evaporative fuel system leaks as small as 0.040
inch between the fuel filler cap and the EVAP canister purge valve
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2002  Chevy Trailblazer.
Question: My 2002 trailblazer is having electrical issues. The hatch and window is locked closed, the
remote doesn't work and the radio doesn't stay on after the car is turned off.
Answer: There is a computer located in the tailgate, called the Liftgate
Module. These are known to go bad and cause the issues you
describe. If the tailgate is locked and you can't open it, you will have to
try to remove the trim panel from the inside and then manually unlatch
the tailgate lock. You should have the vehicle checked for any trouble
codes and if there is communication with the Liftgate Module. If it is
needed to be replace, it will have to be programmed at a dealership to
be fully functional. Be sure to check all fuses, including the fuse box
underneath the left rear seat. Your remotes will have to be
reprogrammed as well. You may also want to try disconnecting the
battery for about 10 minutes and see if that helps too.
11-11-10
i want to know how long or what to do if the code P0455 came out after filling gas
while the engine is running. Do i need to do something. Or where is the vent solenoid
is located?
Comments
If indeed the gas cap was the cause of the check engine
light code P0455, then it will go off by itself after several
starts, driving, off time and restarts. All codes have
different parameters for running the system test. You
could try to disconnect he battery for a few minutes, or
go to one of the large national parts store chains and
have them clear it for free.
11-17-10
I have and 2007impala with and P0455 code had it cleared and it didn't pass
emission test they said too check driving cycle what that.
11-19-10
Sounds like the computer did not run the test for the code P0455 large leak. After
clearing codes, or fixing problem, you cannot go straight to emission test. The car
computer must be given time to run the test for that codes, and have it pass. Also
known as I/M flags. Drive for a few days, then retest.
1-19-11
06 trail blazer 442 code and 455 no leaks what should i check next. I tested that vent
tube sent power with my prob and it closed plug it in it stays open is this the problem.
If you have a P0442 and P0455, you definitely have an
EVAP leak somewhere. The proper way to check is with a
pressurized smoke/nitrogen machine, which you most
likely do not have access to. The 455 is a 'large leak'
and is usually the vent valve back at the gas tank. Even
if you can hear it 'click' that doesn't mean it's not leaking.
The 442 could have set as a result of the 455 or be
something different, like a gas cap that isn't sealing, or a
purge solenoid that doesn't quite shut off, or a leak in
one of the EVAP lines somewhere. I'd start by replacing
the vent valve, they aren't very expensive, then clear the
codes and see if your problem persists.