My truck has been awsome until this point. I am stumped.

lately my torque converter doesn't want to lock up while in OD.

I'm running higher RPM's going down the highway, and it doesn't want to kick in.

If i come to a hill while in 4th with lock up engaged, it will unlock the TC and let it climb easier, but when its time to lock it back up, it won't.

it will even keep doing it going down hill. the only way to get it to work, is to hit the OD button, kick it back to 3rd, then hit it again, and it skips right to 4th with lock-up.

I've replaced the throttle position sensor, the speed sensor, and had it on a scan tool today, driving it around. Also I've had the PCM rewritten at Ford to rule out my programmer.

The PCM isn't even commanding the TC to lock up. it even shows it on the scan tool the tech had, that it was un-locked, but not commanding it to lock when it obviously should have...

eventually it locks and shows the PCM telling it to.

Why is this happening? why won't the pcm command the TC to lock?

Where does the PCM get its info for TC lock-up?

any help, greatly appreciated. the techs everywhere i go have no clue.

 

WELL??????????

ANYBODY?????

I know, its BS!

lol

 

Could be the torque convertor solenoid has gone in the transmission.

 

I don't think that it is.

when the PCM commands the TC to lock, it does.

It seems like its the PCM thats not allowing it to lock up.

when it should obviously lock, the PCM doesn't tell it too.

ruling out mechanical issues....i hope.

The PCM is not getting some piece of information from somewhere. and that is what I'm looking for.

I though the solonoid too, but it works perfect when the PCM tells it to.

 

i see you have a programer, have you tried returning it to stock? newer edges have ability to adjust lockup as well have you adjusted it by accident?

 

stock or programmed, it does it.

its been flashed and rewritten with an adaptive learning strategy from ford.

I need to know what sensors effect the transmission. I'm sure its just a false reading somewhere.

 

just to make sure, this is when the trans is up to temp right? because lockup is not commanded with a cold fluid temp.

 

yup, its up to temp

 

4r70w? What color is your oil at the moment? Is it at the correct level when at tempurature? Are there ANY motor side problem codes present?

I believe if the oil is red and does not smell "burnt", the oil level is just under max at temp in PARK and there are no existing codes engine, transmission or transfer case side of the truck. You may want to investigate the contents of your transmission oil pan. It almost sounds like low oil but also like you have a failing torque convertor.... any other add on mods on the truck itself beside the tuner?

 

The tranny is mint, had the pan off and did the whole works, flush new oil and filter.

the tranny fluid had 45,000km it and the guy said it was like new.

Like i said, the torque converter will lovck when the PCM commands.

but the PCM is not commanding. It has nothing to dso with the tranny. i am sold on that. the scan tool doesn't lie.

I'm getting a false reading somewhere, most likely an engine sensor is malfunctioning, and giving me wrong "engine load" figures causing the TC not to lock.

I have no codes......

 

Ya see this is the problem, WHAT was in the pan when/before you cleaned it and flushed it? As for the scan tool not "lying" don't be so sure, all that tells you is there are no ELECTRICAL functions malfunctioning, if the PCM was unable to engage a selenoid or something was stuck it would give a code. What i need to know is what came out of the pan as doing a flush generally is a cheap and easy way to hide the problems of the tranny it self.

Were there shavings on the magnet in the pan? Was there black dust built up in the base of the pan? Were there any chunks of material laying in the pan? When you changed the filter did you get the old ring out of the hole before stuffing the new one in, it happens to stick up there very easily and quite often.

Again,
1. What color was the old oil at time of flush?
2. What did it smell like?
3. Is it low on fluid CURRENTLY?
4. How does the oil on the dipstick look right now
5. Smell?

I need to know this to direct you to a potential solution but at this point I would say it is a internal problem

 

There was nothing in the pan.

the pan was dropped, new filter, and oil.

I watched him do it. it was doing it before i even did the service.

it was RED like new fluid. smelled like new fluid, looked like it. The tech was like, are you sure you want to dump this fluid?

I'm teling you, this tranny is working great, it is on point everythime, as long as the PCM tells it what to do.

Like you said, if it was mechanical, it should trip a code. I', getting no codes.

I'm getting a false engine load reading or something.

the fluid level is good, and it looks great. no bad smell, just smells like tranny fluid.

I appreciate your interest in helping me. thank you.

 

No.... if it was ELECTRICAL it would push a code, if its MECHANICAL it most likely will not.

Glad to know the fluid and all looked good, but I forgot to ask what was on the magnet in the pan.... too lazy to scroll to see if i asked that before lol. If there is a "porcupine" of material on the magnet, and if you seen it you would know what i mean, then there is a mechanical breakdown beginning.

4R70W is mostly mechanical and fluid run, the electrical side more a less dictates "efficient slippage" and proper engagement.

Lockup is PCM managed given correct circumstances and driving conditions, but if the truck is under more drag, regeared, tuned, etc. lock up will not function as per normal. In my 2k i had this problem with the 35's, I regeared and now my transmission functions much better. Took a lot of strain off the driveline...

Notice any significant loss in mileage? Could be a simple case of E-Brakes are dragging enough to reduce the top end speed... not likely but possible.

I would suspect the tech may have possibily overlooked the ring on the filter... they DO come off in the Valve body from time to time. You did check the tranny fluid with it running in Park after letting it warm up to full temputure correct?

 

I have no idea what is going on.

It goes in tomorrow to an "intrigued" local shop tomorrow. If they can't get to the bottom of it, its going to a guy out of town who over the phone seemed quite confident that he could solve the issue.

I'll keep you posted jay, and will let you know what it turns out to be.

I'm not going to stop till its fixed.

 

Alright goldie, this is seeming to be a interesting problem... what kind of code reader are you using by chance? Some don't have the capability to read all the codes I have noticed. I have a small dedicated code puller that has been known to overlook brand specific codes but will pull any generic codes as well as codes off of imports for no rhyme or reason.

Look forward to finding out your issue.