Replaced the TCC solenoid and that wasn't the issue...but it does seem to be slightly more driveable. I am able to come up to stop signs now and not have it die. It is like when I'm starting to come to the stop, the RPMs drop to about 400 and then something releases and they come back up to 800 or so.

 

I worked as FSE for Ford for 26 years.Your TCC is staying on and stalling engine. Just like pulling to a stop with a manual trans and not depressing clutch

 

not saying its the TCC sol. But in tnat circuit. (harness short to ground) PCM int concern

 

Could you maybe explain the last post? I replaced the TCC solenoid and the harness inside the pan and it seems okay for a while then it will act up. For instance, when I come to a stop, the RPM will be drug down really low, but then something will release and the RPM will go back up to normal.

But today it ran perfectly fine. No telling if tomorrow will be the same story though..

 

He means it could be a short in the wiring between the PCM and the solenoid.

 

Hmm, so something like a wire that got rubbed and maybe grounding out on the body?

It ran perfectly fine today. The weird thing is there is no CEL and the OD light isn't flashing. Have either one of you seen or know of a typical location where grouding may be occuring?

 

If you don't or ever had an OD cancel light flashing, can it be electronic?
Maybe if you are intermittently open upstream?

How is the valve body condition, i.e. is the line pressure OK in D, P , N, R at idle and load?

Also in the valve body there is a torque converter solenoid circuit.... valve, spring, bushing, and solenoid.

How much internal wear do you think the tranny has?

Some thoughts.

 

I almost have a feeling that it is or was electronic. Before I replaced the TCC solenoid, I tried unplugging the harness and I was able to hold an idle. Granted the OD was flashing and it shifted rather aggressively into gear, but that is expected being in limp mode.

How is the pressure? I am not sure as I have not tested that.

How much internal wear? Probably a lot. The truck has ~155K miles and as far as I know, the transmission hasn't been serviced. The factory plugs were still in the bottom of the pan when I dropped it and the magnet was covered in a grey metallic goop. Never had any slipping or shifting problems though.

I just find it weird that replacing the solenoid has "fixed" the problem, but instead of being constant, it seems to be an intermittant problem now. Now my guess is that there is an internal issue with some other parts...maybe removing and replacing the solenoid loosened some parts?

 

Well, other than the TCC motor, there is the EPC and shift solenoids, and the board that you replaced has a temperature sensor.
If anything here you should get a flashing light, even if you had a wire that was broken, but it could still connect giving an "on" condition; the moment of interruption should flash code .......

How about that filter? Is it plugged after 155k?

Possible: valve body wear; pump wear ; torque converter wear.

How long does it take to move when you put in reverse>?

 

Here is a Youtube video of before it was fixed. It seems to engage gears pretty quickly. I repalced the filter and it didn't help.

I can see why you would suggest those parts to be worn....unfortunately that isn't quite easy to verify. And I guess I only have ~153k miles!

http://www.youtube.com/watch?v=UmXCB-Fof9U

 

Well that is the Torque C. Control.

1)There is a mechanical valve in valve body for this 'locking' and 'unlocking' as I mentioned above post.

2) Could be now in torque converter due to this locked condition dragging the engine down..... in other words the bad TCC caused the clutch to go bad or marginalized it now in converter and under certain conditions she won't unlock.

3) I have a hunch there would be a flash on OD light if there is any glitch in the circuit. Lets say if the TCC was in connector half arsed; there would be a flash at the malfunction; or a general problem with an intermittent open circuit. If there was a short, the current would move to the short and bypassing the TCC, and I think you wouldn't get an OD light flash here......

 

So you're leaning towards a short somewhere? I swear, it just puzzles my mind why this is such an intermittant problem. When driving on the highway, it has no problem locking up when getting to speed and no problems unlocking when I give it enough throttle.

You mentioned the EPC earlier. Maybe there isn't enough pressure in the transmission to unlock the converter? I'm honestly not versed in testing the transmisison line pressure. Is that something that can be read in the PIDs with a scanner?

 

Not really.

Unfortunately there isn't an electronic test pressure via a scanner. There are physical taps on the outside of the housing.

If you are shifting in all gears fine, then I'd venture to say it isn't "pressure" per say. But until you know this via a test, it is a shot in the dark.

You could gamble and replace the EPC. EBay has some new Borg Warner ones for $25.


With that many miles and with original oil, though, my leaning is toward a failing T. converter clutch. This failing solenoid just brought this on quicker.... my hunch.

There may be some gurus here that can steer you closer to some trick in isolating this closer.

 

By the way, I wanted to post an update. I ended up just driving the truck around and figured it if blew, then I would be rebuilding the transmission. Well, after driving it, I seem to not have the issue anymore. I'm not sure if there was just something stuck in the TCC circuit that wasn't allowing the clutch to release, but driving it has helped. I think it has died maybe once since my last post so I'm keeping my fingers crossed!

I think the one time it did die was after I made a comment to my friend that it isn't acting up anymore. It is like it has a mind of it's own and can hear my very thoughts!

 

Good. If there was "something" in the valve body TCC circuit, and it flushed out -- great.

If the problem continued I would look at it as: Disassemble the valve body & rebuild it or worst case scenario borrow my dad's transmission jack and replace the torque converter before any debris/garbage circulates.