Code P0449 question

2004 Elantra.

Had it in to the dealer several times for a "Check Engine Light". They
said it's a P0449 code.

History follows:

05/24/05 - Performed a Service Engine Scan. Found one history code
leading to Evap system. Cleared and tested. Customer to
monitor

05/27/05 - Failure Code P0449
Cause: Fuel tube hose was split allowing water into the purge
cannister and cannister filter
Correction: Replace hose and drain water from the cannister
filter

06/01/05 - Cause: Diagnostic Code P0449 Vent Valve circuit cannister
close valve innop.
Correction: Replaced valve

Since that time, the Check Engine Light has been on and off quite a
few times. The car is running fine, but I worry that the light being
on renders it useless, as it could mask other problems that might show
up. This whole thing started not too long after the car was rear-ended
and repaired.

Any ideas?

Thanks,
Larry (lar3ry at sasktel dot net)


Larry

 

First, you should probably find out what code is present now. That'll tell
us whether we're still combatting the same issue or something different.

Presuming you have the P0449 again, the evap. system needs to be checked
for fuel intrusion. Liquid fuel in the evap system can cause vacuum to
not vent properly.

The fuel tank pressure sensor should be checked for proper operation.

The plumbing for the evap system should be checked for proper routing and
connection and condition(possibly collision related).

If you had water in the canister filter or canister itself, it's possible
one or both of these components was damaged, especially the charcoal
canister. Liquid in charcoal canister requires it to be replaced.

 

It seems rather stupid on the part of the dealer to scan and obtain a
code and take no diagnostic action other than to 'clear the code' and
send you on your way, which is precisely what they did on your first
visit.

And, to add to that, P0449 is a 'generic' obd-ii code that says the
failure is in the evap system vent solenoid. What did the dealer do on
trip number 2? They replaced a bad hose. They still(apparently) did not
check the electrical circuit or the physical function of the vent
solenoid.

On trip 3, they replaced the valve, something that should have been
inspected and tested on visit number 1.

If the engine light is on now, run the car down to
checker/autozone/kragen, etc. and have them pull all of the diagnostic
codes out for you(they will perform this service for free), and post
your findings here.

There are four types of OBD-II codes, if they begin with a P it is a
powertrain code. If the first digit is a zero, P0xxx then it is a
'generic' OBD-II code that is common to all OBD-II equipped vehicles.
If the first digit is a 1, P1xxx, then it is a manufactureri-specific
diagnostic code. You will need access to hyundai service literature to
know what a P1xxx code means. However, you can read all about the
'generic' codes here

http://www.obdii.com/codes.html

Let us know what you find out.

Chris

 

The hyundaitech entity posted thusly:

Well, I had the car in for a Service 4 yesterday, and passed on your
suggestions as well as those Chris mentioned.

The following is from the bill:

Complaint:
Customer states that the engine check light is on
Check history codes
Cause:
Scanned and inspected
Found 2 codes dealing with the evap emissions
p0449 and P0445
Inspected and diagnosed that the evap cannister close
valve not functioning as designed
Correction:
Removed and replaced purge cannister close valve
assembly and cleared codes.
Road tested for operation
Found light did not return
Problem corrected

I left the dealership, and stopped at a few places in town. While on
the way home, the light came back on. <sigh>

 

Sent this a while back, but it looks like it didn't get there...


The hyundaitech entity posted thusly:

Well, I had the car in for a Service 4 yesterday, and passed on your
suggestions as well as those Chris mentioned.

The following is from the bill:

Complaint:
Customer states that the engine check light is on
Check history codes
Cause:
Scanned and inspected
Found 2 codes dealing with the evap emissions
p0449 and P0445
Inspected and diagnosed that the evap cannister close
valve not functioning as designed
Correction:
Removed and replaced purge cannister close valve
assembly and cleared codes.
Road tested for operation
Found light did not return
Problem corrected

I left the dealership, and stopped at a few places in town. While on
the way home, the light came back on. <sigh>

 

That can be a hard one to truly clear up. I had to go back 4 times to get it
finished... the last time I was given a loaner car for 3 days. they claimed
it ended up being a pin hole leak in the canister system. as Its the Sulev
engine <'05 Elantra GT hatch> The system will error on a smaller leak than
the standard purge system. Was annoying ...but I looked up the service
procedures in the online manual and they were doing what it says to fix
it....It just can take a while.

Andy C

 

The Andy C entity posted thusly:

Thanks Andy.
They did mention leaving the car overnight. I'll see what I can do
about getting a loaner from them and leaving it.

Larry