My check engine light is on. My Actron Auto scanner shows a Trouble Code P1235 . The fuel flapper is in place. I did a search here couldn't find anything on code P1235. Do the Helm manuals have a list of codes? Thanks in advance. B.
Trouble Code P1235
- Thread starter STORMCAT
- Start date
Thank you ol ' wise one...:bow Do you think a plugged or restricted fuel filter could cause or affect the range ??
- Aug 25, 2006
- 4,436
There is no simple answer STORMCAT
Maybe; however it would take a fairly plugged filter to do so and yet it would be a crap shoot that I would take if you have never replaced it; other than a bit awkward it is painless to replace.
Have you changed the tune recently? Does it only do it under WOT?
Otherwise; if you have a KB boost-a-pump ....... look to this followed by the FPDM ........ followed by fuel pump
I need more data.
Takes care
Shadowman
Hey Bill,
The check engine light just came on one day about two weeks ago and stays on all the time. I haven't changed a thing on the car. Friday night I was out driving and there was a big hesitation above 4000 RPM and that's the only time I have noticed and problems. I bought a Muscle motors cleanable fuel filter a while back. I will throw that in and see if the problem goes away .. fingers crossed. :biggrin
The check engine light just came on one day about two weeks ago and stays on all the time. I haven't changed a thing on the car. Friday night I was out driving and there was a big hesitation above 4000 RPM and that's the only time I have noticed and problems. I bought a Muscle motors cleanable fuel filter a while back. I will throw that in and see if the problem goes away .. fingers crossed. :biggrin
BlackICE
GT Owner
Brian you might try to log the fuel pump duty cycle and voltage along with the fuel rail pressure drop PID with an SCT and Livelink. e.g if you have a high duty cycle and voltage, but low fuel pressure < 35 psi then something isn't right. Other than transient conditions the car tries to keep the fuel pressure around 38 PSI, unless that was changed with a custome tune.
It would be best to compare the data with a know good FGT.
It would be best to compare the data with a know good FGT.
- Aug 25, 2006
- 4,436
STORMCAT
If the nothing changed and the light is persistant; meaning if you clear the code and then soon after it returns I would look towards the FPDM however before replacing parts I would hook her up to the Ford testser aka the VCM/IDS and confirm; this is a laptop based device that many of the technicians own their own so reaching out IMO would be a good move. Certainly if the fuel filter has not been replaced I still encourage replacing it however my hopes that it will correct this issue are low based on that which you have shared.
Takes care
Shadowman
After a lengthy drive with a Ford GT tech in the car with his VCM/IDS PC hooked up they could not find the exact problem. After some home work and some self diagnosis and parts swapping it was just the secondary fuel pump relay that went. They cost $12. and it's about a 5 minute install.. don't waste your time with the FP drivers. Go right to the relays. They are more prone to fail. The contacts are very small and will pit easy
I installed two new relays and my car ran stronger than it has for a long time. I concluded that if you run your car hard the secondary fuel pump relay pulls in and out a lot more then the primary relay so it is going to pit and fail way before the primary relay.
Me being the curious cat I am. I ripped it apart and was shocked to see how small the contact points of the relay. This is the relay that was causing my problem. The pump would run and cut out causing fuel pressure and flow issues. You can see the dark pitted contacts. You can also see this batch was made in China. The new replacements were made in the USA . I think it would be wise to replace the relays at 5000 to 7000 miles to keep them fresh.
I installed two new relays and my car ran stronger than it has for a long time. I concluded that if you run your car hard the secondary fuel pump relay pulls in and out a lot more then the primary relay so it is going to pit and fail way before the primary relay.
Me being the curious cat I am. I ripped it apart and was shocked to see how small the contact points of the relay. This is the relay that was causing my problem. The pump would run and cut out causing fuel pressure and flow issues. You can see the dark pitted contacts. You can also see this batch was made in China. The new replacements were made in the USA . I think it would be wise to replace the relays at 5000 to 7000 miles to keep them fresh.
Attachments
My problem took some time to resolve. There is a funny story evolved. Those of you who know me know I am not a professional mechanic but I am a hands on kinda guy like most of you and I'm pretty good with the wrenches. I avoid going to the dealer for any type of work. I really enjoy taking care of my own girls. When I started to experience the problem it was never at a consistent RPM some times at 4500 RPM, sometimes at 5000 RPM, sometimes at 5500 RPM etc.. a real head scratcher.
I made an appointment to go to see GT tech Mike at Saw Grass Ford. I know Mike personally and know he has worked on many a GT's. I thought he may have seen this trouble code or be familiar with the problem. I wanted him to put their diagnostic PC on my car to see what's going on. The only way to experience the problem is to go out and run the car. The problem is at over 4500 RPM in 1st or 2nd gear the car is going pretty fast so you need to be on a highway type of road.
We jumped on a highway close to the dealership to take some reading as I do some hard pulls thru the gears. It's mid day and you know what kind of attention the GT draws on the road. Cars would speed up to get next to me to catch a glimpse of the GT about that time I go roaring off high in the power band so we could take some readings. I would rapidly speed away from the onlookers.. Than I would slow down so we could look at the data. The cars would speed up to catch me and I would take off again.. after about the third time some of the same cars would pull up next to me with some strange looks on their faces. I am sure some of these people were thinking I was a real jerk wad speeding up and slowing down like I was showing off or something .. If only they knew it was All in the name of science : )
We went back to the dealership to decipher what the GT tech saw. He could read fuel pump pressure and % of duty cycle etc.. . Both were dropping off erratically and sporadically. There was no consistency only that it would happen above 4000 RPM. I didn't know much about the fuel system so the tech gave me a quick education so we could brainstorm on what might be going on. There are two fuel pumps. A primary pump and a secondary pump. The primary FP. handles the load up to 4000 RPM when the pressure drops off the second pump will kick in. Based on the fact that the car would run fine up to 4000 RPM it was obvious something was going on with the secondary pump.
The computer trouble shooting guide said to check the following items in no specific order. Fuel pump drive modules, Fuel pump leads, Fuel pump grounds, ECU grounds and leads and if need be check and or replace the fuel pumps. Mike also mention it could be anything that had to do with signaling the fuel pumps. Even possibly the Throttle position sensor. ( at this point there was no mention of the fuel pump relays by the PC trouble shooting guide or the GT tech) Mike is a straight shooting kind of guy and not really knowing where to start it sounded like a time consuming trial and error project.
I asked him about some of the specific items. He told me the Fuel pump driver modules are behind the splash shields on the passenger side fire wall and there was a dedicated fuel pump ground up near the head lights. He said it was on the passenger side but he doesn't ever recall seeing it. At this point me or any other owner would have to decide wether to leave the car in their hands to try to pin point the problem or try to do some trouble shooting on their own. I was not that keen on someone else ripping into my car so back to my shop I went.
I am lucky to have a back up GT that I could steal parts off and try them to see if something was bad.. During the course of working on and off for about a week I swapped out the Throttle position sensor, the secondary fuel pump module, and checked some of the grounds. Nothing cured the problem.. At this point I still did not know there were fuel pump relays. The way the GT tech talked I was under the impression that the Fuel pump drivers handled all of the fuel pump cycling operations.
I was a little frustrated at this point. I started to look for this dedicated fuel pump ground that the GT tech told me is up near the headlights. For the life of me I could not find it. I went to the GT wiring diagrams.. I as am looking at diagrams I see the Auxiliary relay box with ( 2 ) fuel pump relays listed. This was the point that I learned they existed. I knew from past experience that relays can be a real weak link and I was more than confident this was the problem.. I pulled the relays from the back up car.. popped them in an went for a drive. The car ran perfect.. problem solved !!!
I informed the GT tech and he was happy to be informed of this potential problem. If you have any roughness or drop off in power over 4000 RPM I would go straight for the relays. Even a slightly pitted relay can cause week voltage and erratic fuel pump operation.
So that's my long story.. I am happy to hear it was a quick fix for someone else.. The original part had this number on it F57B-14B192-AA . The new ones had this number on the bag F5TZ-14N089-B . If I recall the actual part in the bag had the same number as the first one listed.
I made an appointment to go to see GT tech Mike at Saw Grass Ford. I know Mike personally and know he has worked on many a GT's. I thought he may have seen this trouble code or be familiar with the problem. I wanted him to put their diagnostic PC on my car to see what's going on. The only way to experience the problem is to go out and run the car. The problem is at over 4500 RPM in 1st or 2nd gear the car is going pretty fast so you need to be on a highway type of road.
We jumped on a highway close to the dealership to take some reading as I do some hard pulls thru the gears. It's mid day and you know what kind of attention the GT draws on the road. Cars would speed up to get next to me to catch a glimpse of the GT about that time I go roaring off high in the power band so we could take some readings. I would rapidly speed away from the onlookers.. Than I would slow down so we could look at the data. The cars would speed up to catch me and I would take off again.. after about the third time some of the same cars would pull up next to me with some strange looks on their faces. I am sure some of these people were thinking I was a real jerk wad speeding up and slowing down like I was showing off or something .. If only they knew it was All in the name of science : )
We went back to the dealership to decipher what the GT tech saw. He could read fuel pump pressure and % of duty cycle etc.. . Both were dropping off erratically and sporadically. There was no consistency only that it would happen above 4000 RPM. I didn't know much about the fuel system so the tech gave me a quick education so we could brainstorm on what might be going on. There are two fuel pumps. A primary pump and a secondary pump. The primary FP. handles the load up to 4000 RPM when the pressure drops off the second pump will kick in. Based on the fact that the car would run fine up to 4000 RPM it was obvious something was going on with the secondary pump.
The computer trouble shooting guide said to check the following items in no specific order. Fuel pump drive modules, Fuel pump leads, Fuel pump grounds, ECU grounds and leads and if need be check and or replace the fuel pumps. Mike also mention it could be anything that had to do with signaling the fuel pumps. Even possibly the Throttle position sensor. ( at this point there was no mention of the fuel pump relays by the PC trouble shooting guide or the GT tech) Mike is a straight shooting kind of guy and not really knowing where to start it sounded like a time consuming trial and error project.
I asked him about some of the specific items. He told me the Fuel pump driver modules are behind the splash shields on the passenger side fire wall and there was a dedicated fuel pump ground up near the head lights. He said it was on the passenger side but he doesn't ever recall seeing it. At this point me or any other owner would have to decide wether to leave the car in their hands to try to pin point the problem or try to do some trouble shooting on their own. I was not that keen on someone else ripping into my car so back to my shop I went.
I am lucky to have a back up GT that I could steal parts off and try them to see if something was bad.. During the course of working on and off for about a week I swapped out the Throttle position sensor, the secondary fuel pump module, and checked some of the grounds. Nothing cured the problem.. At this point I still did not know there were fuel pump relays. The way the GT tech talked I was under the impression that the Fuel pump drivers handled all of the fuel pump cycling operations.
I was a little frustrated at this point. I started to look for this dedicated fuel pump ground that the GT tech told me is up near the headlights. For the life of me I could not find it. I went to the GT wiring diagrams.. I as am looking at diagrams I see the Auxiliary relay box with ( 2 ) fuel pump relays listed. This was the point that I learned they existed. I knew from past experience that relays can be a real weak link and I was more than confident this was the problem.. I pulled the relays from the back up car.. popped them in an went for a drive. The car ran perfect.. problem solved !!!
I informed the GT tech and he was happy to be informed of this potential problem. If you have any roughness or drop off in power over 4000 RPM I would go straight for the relays. Even a slightly pitted relay can cause week voltage and erratic fuel pump operation.
So that's my long story.. I am happy to hear it was a quick fix for someone else.. The original part had this number on it F57B-14B192-AA . The new ones had this number on the bag F5TZ-14N089-B . If I recall the actual part in the bag had the same number as the first one listed.
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Good idea Ralphie, I never did get around to updating my original post. I did so in case someone else runs into this problem and does a search on trouble code issues. I am sure others will incur this problem as they get some more miles on the car. For those who drive in the upper power band I would say it's only a matter of time.
AlHensling
GT Owner
PeteK
GT Owner
Stormcat, thanks for the detailed write-up. This is the kind of tech info that would make an archive search useful. Anyone who has a problem and posts the solution will add to the overall knowledge base.
No problem.. I carry spare realys in my track day box.. My car must be hard on relays. My a/c stopped working working. Turns out the compressor relay went out . It's the same as the fuel pump relays . I had some on hand and was back in the a/c business after a 5 minute change. :biggrin
We need to get your reading glasses prescription updated.. this post is about 4 years old..:biggrin .. But don't worry Helenor will be ready to Roll in Vegas !! :banana