Well, it is a pesky code but will not make the car leave you stranded. Your Neon uses an LDP pump. Follow the large hose that leaves the LDP pump to the rear of the vehicle or the charcoal canister. Try and isolate the small leak. Driving around with scanner connected will not help you. Do not erase codes. You may find leak by crimping the fuel vapor hoses, pressurizing the system with 1/4 PSI and see if still leaks. It is a hard job to do but not impossible. good luck...
p0456 code has been coming on for my 2001 dodge neon for so long now I am ready to just straight blow my car up....... Currently driving around with Diagnostic Machine connected to my car in hopes of code clearing soon. anybody got any idea how to fix this problem
I have a P0449 Evap vent valve solenoid circuit malfunction on a kia spectra. car seems to run fine. im assuming the test i need to run in the evap vent valve light test to see if the right electrical signals are coming to the vent valve?
@kelectr0n The VENT valve is an easy DTC to repair. There is a big chance that your VENT DTC is related to an electrical problem, such as an open or short. Disconnect the vent valve (solenoid) towards the rear of the vehicle and check with a multimeter. You're looking for a broken coil winding, broken wire or a short.
@ADPTraining hello, good advice. it seems that the electricals to the valve are good and the valve seems to work as well. however the pipe that comes out seems to be damaged at the elbow so i have a feeling it cannot sense the valve close? does that make sense?
@kelectr0n Yes, very very good. Good logic. But hear this, DTC P0449 is a control circuit or code relating to the circuit. This means either open or short circuit. Also a problem to the power feed or ground. What you're describing is a performance problem, such as a broken hose, etc.
I would look for a wiring or electrical problem. Almost all OBD-2 DTCs (codes) are either performance or electrical codes. If your DTC was relates to that broken elbow then I think you'd be seeing a performance DTC, as in VENT VALVE LEAK or something like that. The cornerstone of OBD2 diagnostics is identifying whether it's an electrical or performance DTC. Let me know and good luck...
@ADPTraining the mechanic tested the electricals with the bulb just as you recommended, and then he tested the valve itself and it was opening and closing fine.
@kelectr0n It is very odd that you'd get a DTC related to electrical and the cause being a performance problem. Keep in mind this: The ECM looks at the return voltage from the vent valve ground wire at all times. If just for an instant this voltage is lost, such DTC is generated. Resistance in the wires is also a problem.
I rarely recommend it, but at this time I would erase the DTC and drive the vehicle a bit to see if the same DTC is generated.
@ADPTraining CONTINUED: If this happens right away then it is definitely an electrical fault. If it takes a while for the DTC to set, then either the electrical fault is not present at all times or it is related to vibrations or loose connections. Keep me posted. Good luck.
There was a fellow posting a comment on his Eclipse, with symptom of having a hard time filling up with gas. Sorry, I accidentally erased your comment. Please, post again. Here is the possible problem:
All modern vehicles have an anti-vapor gas filling system. This is a purely mechanical system, using a float ball valve within the filler neck or closer to the fuel tank.
If dirt or fuel gum deposits prevent the float ball from returning to its open position, it'll cause exactly the problem you're having.
Your issue is somewhere between the gas cap and the fuel tank. You may have to dismantle a few plastic panels to expose this fuel-fuller mechanism. Then remove and clean thoroughly if you know how to work with gasoline components or show your mechanic.
I have 98 Isuzu Rodeo, the problem is that a few weeks ago the Check Engine will come on with code PO440 (EVAP). The problem is a leak in the EVAP system, you change the gas cap, tighten the hose to the EVAP system, but the light comes every time the gas tank is just a half, I have checked and all information indicates that there is faulty pump gasoline. But I'm not sure what to do.
It looks simple and layout on the computer but when I looked under my car, everything is compact. I still can't fix a code P0446 something about the vent control. Can anyone help me?
Your P0446 is related to the charcoal canister,probably you top off your car enough times to flood the canister with raw liquid fuel,when this happens the canister cannot vent the fuel vapors that it stores until the new EVAP circle is ready to go.
Another possible cause is the fact that the wiring runnig to the cut off valve is broken or both,since all those EVAP componets are exposed to the enviroment those components are common to fail,also check hoses for cracks & pin holes
Well, it is a pesky code but will not make the car leave you stranded. Your Neon uses an LDP pump. Follow the large hose that leaves the LDP pump to the rear of the vehicle or the charcoal canister. Try and isolate the small leak. Driving around with scanner connected will not help you. Do not erase codes. You may find leak by crimping the fuel vapor hoses, pressurizing the system with 1/4 PSI and see if still leaks. It is a hard job to do but not impossible. good luck...
ADPTraining 4 months ago
p0456 code has been coming on for my 2001 dodge neon for so long now I am ready to just straight blow my car up....... Currently driving around with Diagnostic Machine connected to my car in hopes of code clearing soon. anybody got any idea how to fix this problem
lolamizanin 4 months ago
Vac-u-um...LOL
getplaning 6 months ago
good info but the VOICE is fucking STUPID..
dirtylilrat 6 months ago 2
PCV and Purge valves are a common failure especially on VW golfs. I am a Vw tech in training.
tomkkkkk 1 year ago
I have a P0449 Evap vent valve solenoid circuit malfunction on a kia spectra. car seems to run fine. im assuming the test i need to run in the evap vent valve light test to see if the right electrical signals are coming to the vent valve?
kelectr0n 1 year ago
@kelectr0n The VENT valve is an easy DTC to repair. There is a big chance that your VENT DTC is related to an electrical problem, such as an open or short. Disconnect the vent valve (solenoid) towards the rear of the vehicle and check with a multimeter. You're looking for a broken coil winding, broken wire or a short.
ADPTraining 1 year ago
@ADPTraining hello, good advice. it seems that the electricals to the valve are good and the valve seems to work as well. however the pipe that comes out seems to be damaged at the elbow so i have a feeling it cannot sense the valve close? does that make sense?
kelectr0n 1 year ago
@kelectr0n Yes, very very good. Good logic. But hear this, DTC P0449 is a control circuit or code relating to the circuit. This means either open or short circuit. Also a problem to the power feed or ground. What you're describing is a performance problem, such as a broken hose, etc.
ADPTraining 1 year ago
@ADPTraining CONTINUED:
I would look for a wiring or electrical problem. Almost all OBD-2 DTCs (codes) are either performance or electrical codes. If your DTC was relates to that broken elbow then I think you'd be seeing a performance DTC, as in VENT VALVE LEAK or something like that. The cornerstone of OBD2 diagnostics is identifying whether it's an electrical or performance DTC. Let me know and good luck...
ADPTraining 1 year ago
@ADPTraining the mechanic tested the electricals with the bulb just as you recommended, and then he tested the valve itself and it was opening and closing fine.
kelectr0n 1 year ago
@kelectr0n It is very odd that you'd get a DTC related to electrical and the cause being a performance problem. Keep in mind this: The ECM looks at the return voltage from the vent valve ground wire at all times. If just for an instant this voltage is lost, such DTC is generated. Resistance in the wires is also a problem.
I rarely recommend it, but at this time I would erase the DTC and drive the vehicle a bit to see if the same DTC is generated.
ADPTraining 1 year ago
@ADPTraining CONTINUED: If this happens right away then it is definitely an electrical fault. If it takes a while for the DTC to set, then either the electrical fault is not present at all times or it is related to vibrations or loose connections. Keep me posted. Good luck.
ADPTraining 1 year ago
There was a fellow posting a comment on his Eclipse, with symptom of having a hard time filling up with gas. Sorry, I accidentally erased your comment. Please, post again. Here is the possible problem:
All modern vehicles have an anti-vapor gas filling system. This is a purely mechanical system, using a float ball valve within the filler neck or closer to the fuel tank.
ADPTraining 1 year ago
Cont...
If dirt or fuel gum deposits prevent the float ball from returning to its open position, it'll cause exactly the problem you're having.
Your issue is somewhere between the gas cap and the fuel tank. You may have to dismantle a few plastic panels to expose this fuel-fuller mechanism. Then remove and clean thoroughly if you know how to work with gasoline components or show your mechanic.
ADPTraining 1 year ago
Cont 2 ...
This is a little known set of components, whose issues often times go unresolved by some repair shops. Good luck...
ADPTraining 1 year ago
From this country and can't spell "your" YOU NEED EDUCATION!!!
mojoin949 2 years ago
I have 98 Isuzu Rodeo, the problem is that a few weeks ago the Check Engine will come on with code PO440 (EVAP). The problem is a leak in the EVAP system, you change the gas cap, tighten the hose to the EVAP system, but the light comes every time the gas tank is just a half, I have checked and all information indicates that there is faulty pump gasoline. But I'm not sure what to do.
KryzZTyaN 2 years ago
P0443 is what mechanic told me Evap Vent Control total cost 160 he says, but read on line a lot of times somethings just loose and needs tighting
BasDon24 2 years ago
p0455 is my problem. cant find anything for a fix. i guess a $75 diagnostic fee is what i'll have to be paying.
kongphengvang 3 years ago
It looks simple and layout on the computer but when I looked under my car, everything is compact. I still can't fix a code P0446 something about the vent control. Can anyone help me?
2006DURAMAX 3 years ago
Your P0446 is related to the charcoal canister,probably you top off your car enough times to flood the canister with raw liquid fuel,when this happens the canister cannot vent the fuel vapors that it stores until the new EVAP circle is ready to go.
Another possible cause is the fact that the wiring runnig to the cut off valve is broken or both,since all those EVAP componets are exposed to the enviroment those components are common to fail,also check hoses for cracks & pin holes
Gussie2005 2 years ago