just put the terminals back in, put the fuses back in, put the relays back in (all that dealt with the PCM) and it still happens... I'm really thinking about testing a theory and trying to put the OEM sensor back in it and see if it goes back to being intermitten...

 

Thing is, when a wire corrodes it can, with time involve others near by and cause enough disturbance in either sensors or follow the path to yet another.

I don't feel like reading everything over; did you check EVERY fuse in all blocks ?

I know it's a PITA; I would pull the protective cover/taping off the harness itself and look for corrosion.

O2's went from 3 wire sensors to 4 some time ago. The fourth being a direct ground to the PCM. I believe these sensors are the most sensitive, but aren't the problem themselves or you would have a forced an O2 fault and those are usually picked up by the computer.

Shorts, blown fuses and corrosion are dead givaways to problems currently or in the near future.

I'm not a tech or a mechanic by trade. Steve is above and that guy know his chit.... I work on my own stuff most of the time. Yea don't feel like you have been beat, these computer aged trucks can fool a good tech @ times; One that has all the diag equipment handy.

Good Luck.

BTW - The 04 3 valve has the Coil Over Plug (COP) System. Dedicated coil per cylinder. 04 is the first year for 3 valve coils on the 5.4L's.

Don't replace what isn't broke - That CAN have adverse effects :o

I'm not sure if the O2 grounds feed in or near the PCM. Just why the 4rth wire was added = "A direct ground to the PCM"

Not sure about PCM cost and program. Just that allot of people replace those and it doesn't fix the problem.

 

so, i was about to take the new sensor out and try the old sensor in back in it to see what it would do. Well, I got it tore apart, again and decided to look more in depth at the pig tail. I took it from out from under the intake and removed the wire loom.... the 2 wires were cut in the middle with 2 barrel connectors connecting them, but on harness side of the barrel connectors, the wires were COMPLETELY different than on the other. I mean color and even gauge. The wires were pretty shotty on right on either side of the barrel connectors so I cut them and put new ones one. HOPING that this was the end to my misery, I put everything back together (with the new sensor still in) and Started it up............... and the check engine light was still on and the gauge still didn't work.

Oh well, on the way home I stopped at the ford stealership to make an appointment for thursday.. Guess I'm spending the $88 diagnosis/diagnostic fee "which gets applied to my repair if I have it done there" says the service manager with a smile. Raising an eyebrow, great I said, asking if I could speak with the tech before he touches my truck....

I'll let you all know the turn out.

Also, on my way home I picked up a new fuel filter. Not sure if I'm gonna get a chance to put it in before thursday and see if it does anything but I'll try.
duh dum dum..

 

changed the fuel filter and took the negative off the batt like normal... truck runs better, but still have the P1289 code going on, the P0119 is gone.

 

I dropped it off at the stealership last night. They called me about 10am this morning and the customer service guy said that it's the PCM. Apparently the "PCM is not communitcating with the sensors." He quoted me at $535 for a new PCM and 2 hours of labor.

2 hours of labor seems a little off to me seeing how I can have the PCM out and back in in about 15 minutes if I take my time. He said that they have to take the old PCM and transfer data to the new PCM, which he said takes all the time, but also doesn't sound right to me. I thought the PCM's came preload w/ software from ford. Even at that, the tech should just have to hook the PCM up to the ??PID?? and it should do most of the work itself while the tech goes on to work on someone elses vehicle.

He said that the old PCM has to go back, I guess to get refurbished and resold?? Does anyone know if this is true? I told him that I want to see the old one when they take it out (just to make sure they're not selling me something I already own) Does anyone know where they have to send the PCM to get it refurbed?

 

Not exactly sure how that works. Most likely a upgraded base collaborated program < Specially for first year 3 valves. Then I would guess the rest is up-linked/flashed, via Data-Link port.

Personally, I would pay that price without hesitation. BUT , she better run a hell of allot better...

Good Luck - Shoot, it'll prolly feel like a totally different truck once there thru - I mean that in a good way of course

 

yea, I'm paying it... as much as I or anyone hates spending almost a grand without notice, you're right. It better run a hell of a lot better when I get it back. I mean, even when it was in safe mode and I swapped the fuel filter, it ran better... Hopefully, if there were any bugs fixed from the last time this PCM was updated, it will make it run better.

I think performace wise, it will feel like a different truck, but as far as the ride, I can't wait to get rid of the chitty "budget lift" the PO put on it. The front is bounce as all get out and the rear is stiff as heck from the aal's.

If we weren't paying so much for gas and my commute didn't just double, i found a heck of a deal on an 8" rize with rims and tires, but I just can't justify it nowadays....

 

$790.88 later, and the PCM is replaced. Starts better, Accelerates better, theres still a little miss somewhere....


And the damn shutter is still there (but I think it's torque convertor shutter) Not the same shutter the PCM created though...

 

Good to hear things are (mostly) fixed. I have exact same issues in my '05 F150, Does your AC work now and Temp gauge read correctly as well? Based on your story, would you do anything different or take it in to the dealer as you did? I'm like you, mechanically inclined but not into the time consumption and depth of the electronic diagnostics. Therefore not sure whether to tackle myself...anyway, thanks! - Mike

 

The last post in this thread was 11 years ago................

 

Yup thx. But the question stands :-)

 

Hi. You don't need to remove the intake manifold to replace the cylinder head temperature sensor (CHT) and the connector/harness. Remove the alternator, and shine a light in the passenger side tunnel that the intake manifold creates. You'll see the sensor. You can get a 19mm flex head ratcheting wrench on that sensor. As well, you can get the harness connector off too. I wear XL gloves, people consider my hands big, but I was able to do it. No doubt, smaller hands help doing this.