EVAP System code P0440.
11-07-2010, 11:28 AM
#11
TECH Enthusiast
The PCM will only run the EVAP test when the fuel level is between 1/4 and 3/4. If you have checked the cap and the light comes back on several time you probably have a leak somewhere. These can be hard to find. A professional shop will have a smoke machine to help in the diagnosis. There is a small plastic line from the fuel tank to the intake manifold. Near the manifold it has a service port with a Green cap. Make sure this is not loose. Check all other hoses under the hood.
11-07-2010, 11:35 AM
#12
P0440 is evap malfunction, if your gas cap wasn't tight to the point of clicking (3 clicks is the torque spec, belive it or not) theirs a good chance that was the cause. If the fuel has been overfilled, it can be sucked into the charcoal canister causing P0440 but most the time any serious malfuntion of canister, vacuum leak, VSV etc will cause P0440 P0441 P0446 to all be shown.
The PCM will only run the EVAP test when the fuel level is between 1/4 and 3/4. If you have checked the cap and the light comes back on several time you probably have a leak somewhere. These can be hard to find. A professional shop will have a smoke machine to help in the diagnosis. There is a small plastic line from the fuel tank to the intake manifold. Near the manifold it has a service port with a Green cap. Make sure this is not loose. Check all other hoses under the hood.
I was gonna ask too, how much does a dlr. charge for that smoke test?
11-07-2010, 11:50 AM
#13
We charge 1.0 labor to start for an EVAP diagnosis...
Small leaks can be hard to find, all it takes is a pin hole. If anything has been tampered with (ie, fuel pump been replaced), I'd check there first. Guys have used soapy water and very light pressurized air to find leaks, but this can be tough to do, as a lot of folks use too much pressure and end up pinning the pressure sensor. You don't want to use shop air turned all of the way up, or you will definitely be replacing more EVAP parts.
Small leaks can be hard to find, all it takes is a pin hole. If anything has been tampered with (ie, fuel pump been replaced), I'd check there first. Guys have used soapy water and very light pressurized air to find leaks, but this can be tough to do, as a lot of folks use too much pressure and end up pinning the pressure sensor. You don't want to use shop air turned all of the way up, or you will definitely be replacing more EVAP parts.
11-07-2010, 04:11 PM
#15
A tune will not remove it. When my tuner did tune for cam, he got rid of all the codes. That 1 came back. 
Last edited by fastnblu; 11-13-2010 at 05:10 PM. Reason: (sp.)
11-07-2010, 06:16 PM
#16
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i got code p0440 and replaced the gas cap, cleaned the tank vent solenoid,purge valve and hooked them up to 12v power and they click when supplied power. i have heard that if you over fill your tank that could cause the canister to go bad. i always put as much gas as possible in my truck so could that be my problem? it seems like the light comes on right when my truck reaches 3/4 of a tank. i took the canister off and no fuel came out it, sounded like sand was inside, is that normal? im kinda leaning toward the canister being bad. what do yal think?
11-07-2010, 07:14 PM
#17
TECH Enthusiast
Component Location
Evaporative Emission Canister Purge Solenoid On the top right rear of the engine
Customer Concern:
Powertrain Control Module (PCM) code P0440 sets.
Tests/Procedures:
1. Check for dirt in the evaporative hose, evaporative canister, evaporative vent solenoid.
2. Check for obvious signs of leakage in the evaporative hoses, fuel tank filler, fuel cap, etc.
3. Check for leaking Purge Solenoid.
4. Check Fuel Tank Pressure (FTP) sensor grommet.
5. Check fuel level sender O ring.
Potential Causes:
Fuel Cap
Fuel Sender O-Ring
Purge Solenoid
Vent Control Solenoid
Diagnostic Codes:
P0440
Evaporative Emission Canister Purge Solenoid On the top right rear of the engine
Customer Concern:
Powertrain Control Module (PCM) code P0440 sets.
Tests/Procedures:
1. Check for dirt in the evaporative hose, evaporative canister, evaporative vent solenoid.
2. Check for obvious signs of leakage in the evaporative hoses, fuel tank filler, fuel cap, etc.
3. Check for leaking Purge Solenoid.
4. Check Fuel Tank Pressure (FTP) sensor grommet.
5. Check fuel level sender O ring.
Potential Causes:
Fuel Cap
Fuel Sender O-Ring
Purge Solenoid
Vent Control Solenoid
Diagnostic Codes:
P0440
11-08-2010, 09:22 AM
#20
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ok i took off the canister yesterday looking to see if it was filled with fuel but no fuel came out.i figured that may be that was the problem because i always fill my tank as much as possible. it sounded like sand was in there when i shook it, should there be a sandy substance in there?