PaintBaller

Hey All,

I just wanted to relay my recent experiences with the above mentioned DTC code on my 2004 F150 w/5.4. Last week my check engine light came on and I took it over to Advance Auto to have them read the code for me. After finding out what it was, BTW it stands for Camshaft Position Sensor Circuit Bank 1, I came onto the forums and started researching it. After reading just a few threads about it I felt really sick to my stomach. I said to myself, this is going to be a nightmare and cost me a lot of money that I don't have to spend. I read threads where the guys were replacing the sensors, alternators, PCM, cam phasers and all kinds of other parts and none of it seemed to fix the issue. One guy even said the dealer told him to replace the engine for about $6700!

So anyway, after the guy at Advance reset the code, the truck seemed to be running fine. Although I did start to notice that the truck didn't seem to be shifting properly all the time and that the stereo would restart itself occasionally. Well, a few days later, last Friday actually, my Daughter was driving the truck and it started running very rough on her and the CEL came on again and it died at a stop light. She had a hard time getting it started again but eventually it did start and she was able to drive it over to a friends house where it died again. She called me at work and told me what happened so I told her to just leave it and I'll come and check it out after work. So I get off of work and head on over there to see whats going on. One of the things I was planning on doing if the truck wouldn't start or if it did and was running rough was to disconnect the Camshaft Position Sensor. I had read in some of those threads that by disconnecting it the truck would be drivable but would be in limp mode.

So I get over there and fire up the motor and it seems to be running ok. So I decide to take the truck down the road to a Firestone dealer that I've used for the last 12 years and have them check it out for me. As soon as I back it out of the driveway and start heading over there I notice that the truck isn't running right. It seemed to be missing and it wasn't shifting properly and my radio was flashing on and off, not constantly, but here and there. I'm thinking damn, I've got electrical issues, transmission issues, motor issues, this is going to cost me thousands!! So I get it over to Firestone and tell them whats going on and I leave it there for them to work on it on Saturday. I told them to run an electrical system test because I had read that the alternator could be the problem and that the previous owner had told me that he had to replace his alternator and battery at one point. So I'm thinking that maybe he put in a cheap alternator and that it's causing my problems now.

Firestone calls me back on Saturday and says they ran diagnostics on it and that the DTC code was P0340, which is what I had told them it would be, but that the electrical system test was successful and the alternator should be ok. He said the tech did some research on it and said that it was something that they shouldn't get involved with because it could be just about anything and that they didn't want to just start replacing parts and not have it fix the problem. They suggested I take it to the Ford dealer because they are more familiar with these trucks and would most likely have some experience with this particular issue. My heart sank. I told them they were wrong. From what I had read in the forums online that the Ford dealers didn't have any more knowledge on this issue than anyone else and that they would just start replacing parts also and it would end up costing me even more than if they would do the same thing.

So I go and get the truck from Firestone and bring it home. They reset the CEL for me also. The truck didn't seem to be running too bad but I noticed it still wasn't shifting properly and the radio was still restarting itself. I just drove it on some short trips over the weekend to see how it was running and it didn't seem to be too bad except for the issue with the radio. Well, on Tuesday my Daughter was driving my son to day camp and it started acting up again and the CEL came on again. So I figured that I seem to have a serious electrical problem and I decided to call the guy that did the installation on my stereo to see if he would take a look at it. I thought maybe it had something to do with the wiring he did on the installation. He tells me to bring it on down and he'll take a look at it. It was running like **** by this time and on my way down there I had to put it in neutral at the stoplights and step on the gas to keep it from dying.

So I get it over there and he's working on another guys car at the time so I just popped the hood open to let it cool off while I'm waiting on him. I start looking around in the engine compartment at the wiring because I had read that a wiring issue could also be the problem. I'm checking the cables on the battery and any other wiring I could see. As I was standing on the side of the truck by the battery checking the battery cables I looked at the alternator and I noticed that a wiring harness was hanging down and rubbing on the alternator pulley. It was the cable from the batterys positive terminal that connects to the alternator. It had worn all the way thru the harness and down to the bare metal in the wire. When I moved it and it fell back against the pulley it sparked. I'm like, son of a bitch, thats it! We removed the air intake to get better access to the alternator and noticed that the cable should have been run across the top of the alternator but there didn't seem to be anything to hold it in place up there. The wire wasn't worn enough to need replacement so we just covered up the worn area with another piece of a harness he had and taped it up real good with electrical tape and then attached it with wire ties over the top of the alternator. We reset the CEL and took it out for a test drive and it's running just like it did before all this started. Man, was I relieved. After thinking about it, I realized that I probably caused this because I had changed the oil 2 weeks ago and when i did that I removed the air intake to get at the oil filter. I must have knocked that cable loose when I pulled the air intake off and never noticed it hanging down there and then my Daughter had put the air intake back on for me. So that cable was hanging down there bouncing against the alternator pulley for a couple of weeks.

Anyway, I'm sorry for such a long post, but after reading the HORROR stories in some of those other threads I wanted to tell my story in case it helps someone else solve this problem down the road. It ended up costing me less than $200. I had to pay Firestone $135 for the time they spent on it and I gave $40 to the guy that does my electrical work.

big cube 426

thanks for the heads up. glad to hear you got out of it cheap.

TxOutlaw

Holy smoke... P0340 is kickin my butt... On a 2002 tho... I have searched till blue in the face... We replaced the sensor before searching around. Of course that didn't fix it... We are running it with sensor unplugged and watching alternator voltage via the scangauge2 right now...

Hoping it's something this simple at this point...

cham

I may be going through something similar. I've been reading a P0340 and P0344 for about a week now off of a Innova Quicklink. And it has been recommending to replace the camshaft position sensor (CMP), alternator, and variable camshaft (VCT) solenoid.

So today I replaced the battery, alternator and the CMP. It was getting late and I was curious if it would clear, and it did. Started the truck and revved it multiple times then killed it and repeated several times. Nothing came up so I took it out for a 15ish mile drive, both stop'n go and highway, while running multiple diagnostic tests with the Quicklink while driving in the 30mph range and at 60 on the highway; everything was good. Yet the moment I pull into my drive way I get all of the above codes again.

Now in my case I've been gearing up to do a complete engine rebuild for months now so I don't mind buying the parts, but I'm going to pissed if it's a wire.