Code P0449 - need info
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 4,477
Likes: 2
From: Boca Raton, FL
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Code P0449 - need info
I had the "check gas cap" and "CEL" on for a few weeks, CEL was not flashings so I didn't pay much attention to it. I've changes gas caps at least 3 times and now have the chrome one from Pipedreams on. It fits tighter than the OEM one.
Went to Auto Zone this morning and they put the OBD II on the C6 (NM6) and got a P0449 code. Looked it up on the CF and here's the reading: "Evaporative Emission (EVAP) Vent Solenoid Control Circuit ECM". They also cleared both readings for free. Thanks AutoZone
OK, a couple of questions: 1) what does this mean? 2) how is it fixed? 3) what does ECM mean?
FYI, I've modded the engine with the following:
AFR 225 Heads
Cam 224 230 581/592 114 LSA
Underdrive Pulley
Corsa Sports
Dynatech Supermaxx Headers
Halltech Stinger w/CAI
160 Degree Thermostat
Tuned
Could any of the above cause the code?
Thanks,
Jeff
Went to Auto Zone this morning and they put the OBD II on the C6 (NM6) and got a P0449 code. Looked it up on the CF and here's the reading: "Evaporative Emission (EVAP) Vent Solenoid Control Circuit ECM". They also cleared both readings for free. Thanks AutoZone
OK, a couple of questions: 1) what does this mean? 2) how is it fixed? 3) what does ECM mean?
FYI, I've modded the engine with the following:
AFR 225 Heads
Cam 224 230 581/592 114 LSA
Underdrive Pulley
Corsa Sports
Dynatech Supermaxx Headers
Halltech Stinger w/CAI
160 Degree Thermostat
Tuned
Could any of the above cause the code?
Thanks,
Jeff
Safety Car
Joined: Jul 2001
Posts: 4,456
Likes: 6
From: Spicewood, Texas, USA TX-Texas
A good opportunity to try out my new service manuals:
DTC P0449 = "The control module detects that the commanded state of the driver (device causing EVAP canister vent valve to operate) and the actual state of the control circuit do not match".
As I understand the service manual, the EVAP canister vent valve is supposed to be closed above 400 rpm with normal system voltage. P0449 is set when the control module thinks the valve should be closed and the circuit feedback says it's not (or vice-versa); this condition has to exist for at least five seconds and occur twice for the code to be set. This doesn't necessarily mean the vent valve isn't working properly...it may just mean the CM isn't getting the proper signal back.
If this condition started immediatedly after the tune, I would suspect the tune not having covered all the bases. This is educated speculation without more info on the tune. If onset didn't coincide exactly with the tune, it's probably unrelated to your mods...just the usual warranty problem.
DTC P0449 = "The control module detects that the commanded state of the driver (device causing EVAP canister vent valve to operate) and the actual state of the control circuit do not match".
As I understand the service manual, the EVAP canister vent valve is supposed to be closed above 400 rpm with normal system voltage. P0449 is set when the control module thinks the valve should be closed and the circuit feedback says it's not (or vice-versa); this condition has to exist for at least five seconds and occur twice for the code to be set. This doesn't necessarily mean the vent valve isn't working properly...it may just mean the CM isn't getting the proper signal back.
If this condition started immediatedly after the tune, I would suspect the tune not having covered all the bases. This is educated speculation without more info on the tune. If onset didn't coincide exactly with the tune, it's probably unrelated to your mods...just the usual warranty problem.
Last edited by JmpnJckFlsh; Jun 4, 2006 at 12:18 PM.
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 4,477
Likes: 2
From: Boca Raton, FL
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Originally Posted by JmpnJckFlsh
A good opportunity to try out my new service manuals:
DTC P0449 = "The control module detects that the commanded state of the driver (device causing EVAP canister vent valve to operate) and the actual state of the control circuit do not match".
As I understand the service manual, the EVAP canister vent valve is supposed to be closed above 400 rpm with normal system voltage. P0449 is set when the control module thinks the valve should be closed and the circuit feedback says it's not (or vice-versa); this condition has to exist for at least five seconds and occur twice for the code to be set. This doesn't necessarily mean the vent valve isn't working properly...it may just mean the CM isn't getting the proper signal back.
If this condition started immediatedly after the tune, I would suspect the tune not having covered all the bases. This is educated speculation without more info on the tune. If onset didn't coincide exactly with the tune, it's probably unrelated to your mods...just the usual warranty problem.
DTC P0449 = "The control module detects that the commanded state of the driver (device causing EVAP canister vent valve to operate) and the actual state of the control circuit do not match".
As I understand the service manual, the EVAP canister vent valve is supposed to be closed above 400 rpm with normal system voltage. P0449 is set when the control module thinks the valve should be closed and the circuit feedback says it's not (or vice-versa); this condition has to exist for at least five seconds and occur twice for the code to be set. This doesn't necessarily mean the vent valve isn't working properly...it may just mean the CM isn't getting the proper signal back.
If this condition started immediatedly after the tune, I would suspect the tune not having covered all the bases. This is educated speculation without more info on the tune. If onset didn't coincide exactly with the tune, it's probably unrelated to your mods...just the usual warranty problem.
, now, please put this in English :o
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 4,477
Likes: 2
From: Boca Raton, FL
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Originally Posted by JmpnJckFlsh
Let's start with a single simple question: How soon after the tune did you first notice the CEL on?
Immediately after the tune the CEL was not on. A week later it came on and was turned off by the tuner using his OBD II.
As I noted earlier, I've had 3 OEM gas caps and now using an after market one that fits tighter. The dealer has always claimed that the faulty gas cap caused the CEL.
Now, with the mod I've done, not sure the dealer will check this out under the warrenty agreement.
Will driving with this condition cause any engine damage, etc?
Thanks.
Safety Car
Joined: Jul 2001
Posts: 4,456
Likes: 6
From: Spicewood, Texas, USA TX-Texas
Originally Posted by schilitj
This is not the first time. It happened before the tune and the dealer attributed it to a faulty gas cap.
. It's strictly an electrical check to verify a mechanical action based only on the engine running or not running. It has nothing to do with the gas cap. Take it back to the dealer...or better yet, find a dealer with a tech that knows how to read the service manual.
Originally Posted by schilitj
...Now, with the mod I've done, not sure the dealer will check this out under the warrenty agreement.
Will driving with this condition cause any engine damage, etc?...
Will driving with this condition cause any engine damage, etc?...
Edit: All of the above is an explanation for your P0449 code. If you have gotten a "Check Gas Cap" message, it would be a different code. If you are not currently getting the "Check Gas Cap" message, that condition has probably been corrected and the code reset.
Last edited by JmpnJckFlsh; Jun 4, 2006 at 03:44 PM.
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 4,477
Likes: 2
From: Boca Raton, FL
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Originally Posted by JmpnJckFlsh
There you go...not related to the mods/tune...or the gas cap . It's strictly an electrical check to verify a mechanical action based only on the engine running or not running. It has nothing to do with the gas cap. Take it back to the dealer...or better yet, find a dealer with a tech that knows how to read the service manual.
If they say it's from your mods, they are full of it...Either the EVAP vent valve isn't working, or the ECM isn't getting good info about it's operation. I doubt that the EVAP vent valve not working will cause any damage, but I would get it fixed. If something else really bad happens, you'll want that CEL coming on just for that, not some harmless pre-existing condition.
Edit: All of the above is an explanation for your P0449 code. If you have gotten a "Check Gas Cap" message, it would be a different code. If you are not currently getting the "Check Gas Cap" message, that condition has probably been corrected and the code reset.
. It's strictly an electrical check to verify a mechanical action based only on the engine running or not running. It has nothing to do with the gas cap. Take it back to the dealer...or better yet, find a dealer with a tech that knows how to read the service manual.If they say it's from your mods, they are full of it...Either the EVAP vent valve isn't working, or the ECM isn't getting good info about it's operation. I doubt that the EVAP vent valve not working will cause any damage, but I would get it fixed. If something else really bad happens, you'll want that CEL coming on just for that, not some harmless pre-existing condition.
Edit: All of the above is an explanation for your P0449 code. If you have gotten a "Check Gas Cap" message, it would be a different code. If you are not currently getting the "Check Gas Cap" message, that condition has probably been corrected and the code reset.
Jeff
Safety Car
Joined: Jul 2001
Posts: 4,456
Likes: 6
From: Spicewood, Texas, USA TX-Texas
I believe P0449 indicates the root cause...the fact that you got the "Check Gas Cap" message could be related to code P0449 because improper operation of the EVAP canister vent valve affects the pressure inside the fuel tank. This could cause the fuel tank pressure to be outside of the expected range.
Fuel tank pressure out of range could then cause the ECM to also throw a related code (not sure which, something like P045X); the DIC would display this problem as "Check Gas Cap". If the fuel tank pressure condition satisfies the test criteria for three start-ups, the code will be automatically turned off.
Fuel tank pressure out of range could then cause the ECM to also throw a related code (not sure which, something like P045X); the DIC would display this problem as "Check Gas Cap". If the fuel tank pressure condition satisfies the test criteria for three start-ups, the code will be automatically turned off.
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