Capless fuel filler and check engine light
02-15-2018, 07:15 AM
#91
I've been following this post pretty much since the beginning since I was also having this same issue.
I used to always get this code every spring and fall when the weather was getting damp and turning colder and starting to freeze. Never in the summer or in the dead of winter. I started heating my garage a couple of years ago and I have never got this code since. I also haven't replaced any parts related to this issue. Its related to damp and cold (just at freezing) weather.
I used to always get this code every spring and fall when the weather was getting damp and turning colder and starting to freeze. Never in the summer or in the dead of winter. I started heating my garage a couple of years ago and I have never got this code since. I also haven't replaced any parts related to this issue. Its related to damp and cold (just at freezing) weather.
02-16-2018, 06:46 PM
#92
Senior Member
New details
I have spent some time researching this issue and have come up with some new details. The PCM runs a specific test to determine if the P0451 offset condition exists. This test is only one component of the overall evap test.
This test runs when the truck is initially started. The computer is looking to see if there is a condition where excessive pressure or vacuum exists in the fuel tank. This specific test executes every start cycle regardless of outside temperature or fuel level. The only requirement for the computer to execute this specific test is that the car must have sat previously for 2 hours. Here is the Ford document that explains details for obd tests for the 2010 MY.
Specifically, P0451 will set if the computer sees the FTP pressure to be more than 2.0 in H20, OR, less than -2.0 in H20 during engine start.
With this background knowledge, I looked at Ford’s HX39 procedure again (the instructions Ford provides to troubleshoot this issue). There are essentially 2 reasons this excessive pressure/vacuum condition would exist.
Last night, the conditions outside were ripe to set the code in my truck (cold + rain). I went out this morning and hooked up my analyzer before starting the vehicle. The FTP sensor read 14.45 in H20. At this value, the computer should set P0451. To rule out #1 above, I put in the supplemental refueling adapter and continued to monitor the FTP pid. No change. There is not excessive pressure in my tank. I started the vehicle, and sure enough, P0451 set. Because of this excessive pressure condition, I can rule out the #1 and capless fuel filler being the culprit for my issue that others have mentioned.
During the drive in to work, the FTP pid remained around the same value. After sitting all day in the dry sun, the FTP pid read around 1.5 in H20 on the way home.
I remember noticing that the actual FTP sensor sits between the truck cab and the truck bed. From up-top, if you shine a flashlight in the gap, you will actually see the top of the FTP sensor and wiring. Essentially, the FTP sensor is exposed to the elements. I decided to drop a bucket of water on this area and monitored the FTP pid. Sure enough, the pressure started to rise to an unacceptable level.
I do not know for sure if the sensor or wiring is at fault. I am leaning towards senor as the PCM analyzes the voltage coming back from the sensor and as voltage increases, so does pressure.
Too bad the FTP sensor is only sold as an assembly with associated fuel lines at a cost of $300+ from the dealer.
I may try shielding the actual sensor from water by enclosing it in a plastic bag with zip ties, knowing there will be small holes for the wiring and fuel lines.
This test runs when the truck is initially started. The computer is looking to see if there is a condition where excessive pressure or vacuum exists in the fuel tank. This specific test executes every start cycle regardless of outside temperature or fuel level. The only requirement for the computer to execute this specific test is that the car must have sat previously for 2 hours. Here is the Ford document that explains details for obd tests for the 2010 MY.
Specifically, P0451 will set if the computer sees the FTP pressure to be more than 2.0 in H20, OR, less than -2.0 in H20 during engine start.
With this background knowledge, I looked at Ford’s HX39 procedure again (the instructions Ford provides to troubleshoot this issue). There are essentially 2 reasons this excessive pressure/vacuum condition would exist.
- There is a problem with the EVAP system / purge solenoid / charcoal canister where there really is excessive pressure or vacuum in the fuel tank.
- The FTP sensor is giving false readings.
Last night, the conditions outside were ripe to set the code in my truck (cold + rain). I went out this morning and hooked up my analyzer before starting the vehicle. The FTP sensor read 14.45 in H20. At this value, the computer should set P0451. To rule out #1 above, I put in the supplemental refueling adapter and continued to monitor the FTP pid. No change. There is not excessive pressure in my tank. I started the vehicle, and sure enough, P0451 set. Because of this excessive pressure condition, I can rule out the #1 and capless fuel filler being the culprit for my issue that others have mentioned.
During the drive in to work, the FTP pid remained around the same value. After sitting all day in the dry sun, the FTP pid read around 1.5 in H20 on the way home.
I remember noticing that the actual FTP sensor sits between the truck cab and the truck bed. From up-top, if you shine a flashlight in the gap, you will actually see the top of the FTP sensor and wiring. Essentially, the FTP sensor is exposed to the elements. I decided to drop a bucket of water on this area and monitored the FTP pid. Sure enough, the pressure started to rise to an unacceptable level.
I do not know for sure if the sensor or wiring is at fault. I am leaning towards senor as the PCM analyzes the voltage coming back from the sensor and as voltage increases, so does pressure.
Too bad the FTP sensor is only sold as an assembly with associated fuel lines at a cost of $300+ from the dealer.
I may try shielding the actual sensor from water by enclosing it in a plastic bag with zip ties, knowing there will be small holes for the wiring and fuel lines.
Last edited by mtech; 02-16-2018 at 06:55 PM.
02-25-2018, 09:10 AM
#93
Senior Member
Lol! not trying, as I didn't realize how old it was, but Im sure there is still plenty of funnel banging still taking place if you own a ford like ours! And it looks like this could be a stuck open purge solenoid, correct?
02-25-2018, 09:23 AM
#94
Senior Member
Hello guys, I just got through dealing with the notorious Y connector fix, So Im looking forward to this problem too, LOL!! I would say that in the winter the cold and damp is going to naturally cause your fuel tank pressure to be less and In the summer time and the heat you will build more fuel tank pressure vapor and this is why you see it more in the cold, just like the O rings shrinking more in the winter time on the y connectors. This may be getting the FTP sensor reading out of range. On another note my sons 2001 ford ranger had a check engine evaporate light and Ford wanted to replace the evaporation lines and FTP sensor on it. I got under the truck and felt on top of the fuel pump in gas tank followed wires with my hand and found a broken wire, Reconnected wire and that was like years ago, and still good. So the fix may be the filler neck for most, you know a dealer will through parts at a problem at your expense. I will keep up with this as i am sure to see it. Thanks to all for contributing, maybe we can come up with a easy less expensive fix.
I have spent some time researching this issue and have come up with some new details. The PCM runs a specific test to determine if the P0451 offset condition exists. This test is only one component of the overall evap test.
This test runs when the truck is initially started. The computer is looking to see if there is a condition where excessive pressure or vacuum exists in the fuel tank. This specific test executes every start cycle regardless of outside temperature or fuel level. The only requirement for the computer to execute this specific test is that the car must have sat previously for 2 hours. Here is the Ford document that explains details for obd tests for the 2010 MY.
Specifically, P0451 will set if the computer sees the FTP pressure to be more than 2.0 in H20, OR, less than -2.0 in H20 during engine start.
With this background knowledge, I looked at Ford’s HX39 procedure again (the instructions Ford provides to troubleshoot this issue). There are essentially 2 reasons this excessive pressure/vacuum condition would exist.
Last night, the conditions outside were ripe to set the code in my truck (cold + rain). I went out this morning and hooked up my analyzer before starting the vehicle. The FTP sensor read 14.45 in H20. At this value, the computer should set P0451. To rule out #1 above, I put in the supplemental refueling adapter and continued to monitor the FTP pid. No change. There is not excessive pressure in my tank. I started the vehicle, and sure enough, P0451 set. Because of this excessive pressure condition, I can rule out the #1 and capless fuel filler being the culprit for my issue that others have mentioned.
During the drive in to work, the FTP pid remained around the same value. After sitting all day in the dry sun, the FTP pid read around 1.5 in H20 on the way home.
I remember noticing that the actual FTP sensor sits between the truck cab and the truck bed. From up-top, if you shine a flashlight in the gap, you will actually see the top of the FTP sensor and wiring. Essentially, the FTP sensor is exposed to the elements. I decided to drop a bucket of water on this area and monitored the FTP pid. Sure enough, the pressure started to rise to an unacceptable level.
I do not know for sure if the sensor or wiring is at fault. I am leaning towards senor as the PCM analyzes the voltage coming back from the sensor and as voltage increases, so does pressure.
Too bad the FTP sensor is only sold as an assembly with associated fuel lines at a cost of $300+ from the dealer.
I may try shielding the actual sensor from water by enclosing it in a plastic bag with zip ties, knowing there will be small holes for the wiring and fuel lines.
This test runs when the truck is initially started. The computer is looking to see if there is a condition where excessive pressure or vacuum exists in the fuel tank. This specific test executes every start cycle regardless of outside temperature or fuel level. The only requirement for the computer to execute this specific test is that the car must have sat previously for 2 hours. Here is the Ford document that explains details for obd tests for the 2010 MY.
Specifically, P0451 will set if the computer sees the FTP pressure to be more than 2.0 in H20, OR, less than -2.0 in H20 during engine start.
With this background knowledge, I looked at Ford’s HX39 procedure again (the instructions Ford provides to troubleshoot this issue). There are essentially 2 reasons this excessive pressure/vacuum condition would exist.
- There is a problem with the EVAP system / purge solenoid / charcoal canister where there really is excessive pressure or vacuum in the fuel tank.
- The FTP sensor is giving false readings.
Last night, the conditions outside were ripe to set the code in my truck (cold + rain). I went out this morning and hooked up my analyzer before starting the vehicle. The FTP sensor read 14.45 in H20. At this value, the computer should set P0451. To rule out #1 above, I put in the supplemental refueling adapter and continued to monitor the FTP pid. No change. There is not excessive pressure in my tank. I started the vehicle, and sure enough, P0451 set. Because of this excessive pressure condition, I can rule out the #1 and capless fuel filler being the culprit for my issue that others have mentioned.
During the drive in to work, the FTP pid remained around the same value. After sitting all day in the dry sun, the FTP pid read around 1.5 in H20 on the way home.
I remember noticing that the actual FTP sensor sits between the truck cab and the truck bed. From up-top, if you shine a flashlight in the gap, you will actually see the top of the FTP sensor and wiring. Essentially, the FTP sensor is exposed to the elements. I decided to drop a bucket of water on this area and monitored the FTP pid. Sure enough, the pressure started to rise to an unacceptable level.
I do not know for sure if the sensor or wiring is at fault. I am leaning towards senor as the PCM analyzes the voltage coming back from the sensor and as voltage increases, so does pressure.
Too bad the FTP sensor is only sold as an assembly with associated fuel lines at a cost of $300+ from the dealer.
I may try shielding the actual sensor from water by enclosing it in a plastic bag with zip ties, knowing there will be small holes for the wiring and fuel lines.
Last edited by Koolponycar; 02-25-2018 at 09:34 AM.
02-25-2018, 09:31 AM
#95
Senior Member
The ranger FTP sensor on his 2001 is in the fuel pump assembly setting right between the cab and the bed like you said, and you can look between on the drivers side and see it. It has a large lock ring around it. If the fuel pump ever goes out then I will either drop the tank or pull the bed and repair that wire even better with some heat shrink, as it will be safe to do that then. I just wrap it with some and taped it up for now.
02-25-2018, 09:45 AM
#96
Senior Member
mtech, one other thing, if you can get to the FTP sensor try unplugging it and let it dry out and put some dielectric grease back in it and plug it back up if you don't find any bad wires, before replacing it.
04-02-2018, 11:28 PM
#97
Junior Member
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purge valve solenoid
*knock on wood* but I haven't had a CEL in some time now after funnel banging my truck (once again) and I played around with the fuel door before banging it. I did hear stuff dropping, so something was clearly stuck/glogged in the fill somehow. But, now I am having some stuttering/starting issues after I fill my tank. No CEL, but only after I fill my tank (no matter what level I started and/or finished at) the truck really struggles to start. This happen to any of you guys yet? I am still thinking its an EVAP leak/vacuum pressure issue.
05-01-2018, 01:07 AM
#98
I'm going to join the crowd here. 2011 fx4 eco, bought my truck used 2 years ago. after the first few months the code P0457 came up. researched it, did the funnel bang job, reset it, and it seemed to stay off....... for awhile that is. it would come back on every now and then, i would always just clear the code. but now for the last 2 or 3 months it basically comes back on pretty quick after I clear it so i have just stopped clearing it and just hit the ok button every time I start the truck. i have also started to get code P144C, are these two codes related at all. 144c code turns on the check engine light. I've never notice anything performance wise and the truck runs fine. contemplating taking into the dealership, just don't wanna spend the money on something there just going to take a wild guess on it seems.
also, would either of these codes mess with gas mileage? I commute about 20 miles each way, 80% freeway and only manage around 15mpg, and that drops to 12-13 if im towing my trailer. seems a little low to me.
also, would either of these codes mess with gas mileage? I commute about 20 miles each way, 80% freeway and only manage around 15mpg, and that drops to 12-13 if im towing my trailer. seems a little low to me.
05-01-2018, 12:05 PM
#99
Senior Member
Jstilt - I'm going to join the crowd here. 2011 fx4 eco, bought my truck used 2 years ago. after the first few months the code P0457 came up. researched it, did the funnel bang job, reset it, and it seemed to stay off....... for awhile that is. it would come back on every now and then, i would always just clear the code. but now for the last 2 or 3 months it basically comes back on pretty quick after I clear it so i have just stopped clearing it and just hit the ok button every time I start the truck. i have also started to get code P144C, are these two codes related at all. 144c code turns on the check engine light. I've never notice anything performance wise and the truck runs fine. contemplating taking into the dealership, just don't wanna spend the money on something there just going to take a wild guess on it seems.
also, would either of these codes mess with gas mileage? I commute about 20 miles each way, 80% freeway and only manage around 15mpg, and that drops to 12-13 if im towing my trailer. seems a little low to me.
also, would either of these codes mess with gas mileage? I commute about 20 miles each way, 80% freeway and only manage around 15mpg, and that drops to 12-13 if im towing my trailer. seems a little low to me.
P144C - EVAPORATIVE EMISSION (EVAP) SYSTEM PURGE FLOW PERFORMANCE DURING BOOST
For pertinent information, other's experience / resolution, etc. ...Google [ ford 2011 f-150 code P144C ]
.
Last edited by gDMJoe; 05-01-2018 at 12:12 PM.
05-04-2018, 07:34 PM
#100
[QUOTE=Jstilt;5758786]I'm going to join the crowd here. 2011 fx4 eco, bought my truck used 2 years ago. after the first few months the code P0457 came up. researched it, did the funnel bang job, reset it, and it seemed to stay off....... for awhile that is. it would come back on every now and then, i would always just clear the code. but now for the last 2 or 3 months it basically comes back on pretty quick after I clear it so i have just stopped clearing it and just hit the ok button every time I start the truck. i have also started to get code P144C, are these two codes related at all. 144c code turns on the check engine light. I've never notice anything performance wise and the truck runs fine. contemplating taking into the dealership, just don't wanna spend the money on something there just going to take a wild guess on it seems.
also, would either of these codes mess with gas mileage? I commute about 20 miles each way, 80% freeway and only manage around 15mpg, and that drops to 12-13 if im towing my trailer. seems a little low to me.[/QUOTE
Sounds like a stuck open purge valve to me. Yes they can affect fuel mileage and drivability if they get stuck open.
also, would either of these codes mess with gas mileage? I commute about 20 miles each way, 80% freeway and only manage around 15mpg, and that drops to 12-13 if im towing my trailer. seems a little low to me.[/QUOTE
Sounds like a stuck open purge valve to me. Yes they can affect fuel mileage and drivability if they get stuck open.
Last edited by Redfox92; 05-04-2018 at 07:36 PM.
