5.0 torque converter tuning issue? | Ford Explorer Forums - Serious Explorations

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5.0 torque converter tuning issue?

Dono

347 V8 Limited turbo
Elite Explorer
Joined
February 18, 2009
Messages
5,331
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614
City, State
Winnipeg, Manitoba
Year, Model & Trim Level
00 Limited V8
I've been struggling with overdrive coming and going.
In the midst of this, I've been doing all kinds of other things also.
Turbo, 347 motor etc.

Now, I 'think' I always had a lockup issue as I am totaly amazed at how low the rpm's go when locked up. I'm pretty well convinced its tuning, or something telling the computer not to lock up as there are no codes.

I did manage to re-create the issue, and now I know how to make the issue go away temporarily. I know all I need to do is re-flash the pcm and I get tc lockup for a few days.

Here's what I did:
While I had no TC lockup, I picked all the pids that I could see having anything to do with torque converter, including rpm and speed of course. Knowing that some pids just won't work at all, I felt I'd be able to determine the non working ones.

I went for a short drive, logging the pids.
Then, I re-flashed my pcm and went for another drive. I logged this drive also.

I now have a comparison.

Check out the speed/rpm difference:
At 57mph with lockup I'm at 1700rpm versus 2425rpm with no lockup
Crazy difference. If anyone would like to see the supporting logs, feel free to pm me your email address.
Here is what stood out immediately.
The pid 'UNLOCKED DUE TO SHIFTING|2|224|2|0' is always on ( 1 ) looking at the datalog of no converter lockup. This pid is always zero on the datalog that has lockup. What is this? Why is it stuck on? Is it labeled completely incorrectly on the sct device? What do I look for next?
 



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datalog

Can you email me the datalog, I would like to look it over.

Also, does your "over drive off light" work? Yes or No?

Did you datalog slip across the torque converter or something like that?
 






Logs sent.
Yes, slip across converter is one of the pids logged.
Yes, OD light works. So does OD. The rev's increase and the light comes on when the button is pressed.
 






datalog

Can you do another log with TPS included, need that pid.
Also can you do a datalog where it goes from working to not working or does the problem only happen after restarting it?
 






The tc lockup goes away after about 3 days of driving. Since I re-flashed, it will be about 3 days before I can get you a log with the tps showing the tc not locking up.

I can log the tc locking up with the throttle position sensor pid tonight.

I'm not surprised I missed a pid that you require. I'm learning........
 






Pids

I did the same thing with all those trans pids when I had a slipping lock up torque converter clutch due to a valve body problem. I had looked at the datalog and was like, man, I need the TPS in there. LOL.

Could you also add commanded and desired gear pids?
 






Trans

Also keep a close eye on it, let me know when the problem shows up again if it works then doesn't work on the same test drive or if it works on one and then not the other test drive.

What I am thinking about is that when a problem is noticed by the PCM it may be shutting down the TCC on purpose. But no codes, no flashing O/D light makes you think it is not that.

There are other things that shut down TCC lock up that are not problems, like stepping on the brake pedal etc. TCC has to be unlocked when coming to a stop or it will feel like stopping a manual transmission vehicle without stepping on the clutch pedal. (GM's used to have that problem with sticking TCC solenoid).
 






Pids

Oh, and add vehicle speed.

On my truck the rear diff speed sensor sends signal to ABS module which converts it to a DC signal and sends it out to all the other modules.
Imagine if I lost the vehicle speed signal wire from just the ABS to the PCM. Speedometer would still work, but PCM would not know what gear it should be in or when to lock the TCC.

Would set a code in PCM though...
 






Million posts

Sorry for million posts in a row but...
Are you checking for codes with a scan tool?
The check engine light may not come on even though there is a code set, if it is not emission related.
 






I think your right. From the drivers seat there doesn't seem to be any symptoms that I can tell of (so far) that tells the pcm to kill the tc lockup feature.

I will create a fresh set of pids, removing all the ones that don't seem to do anything. This will make room for the requested pids for logging.
 






Sorry for million posts in a row but...
Are you checking for codes with a scan tool?
The check engine light may not come on even though there is a code set, if it is not emission related.

No, I have not checked for codes. I will check them next time I loose tc lockup. Keep in mind, I do not have the ability to check transmission codes.
 






Trans codes

Trans codes would show up in the PCM since there is no separate transmission computer.
Scan tools vary on what they will show though. With a factory scan tool I get a code for my PCM rom being incorrect, because of the sct tune. With the X3 I never saw the rom code, like it is designed to ignore it.
 






rpm difference between lockup, and not locked

Here are a couple pics showing the difference on lockup to no lockup.

I lost tc lockup very quickly today. No codes thrown. A re-flash on the pcm and I was back with lockup working. I did loose it shortly after the log was completed though.

I can also confirm I don't have lockup when the rpm's change very quickly with a very slight push on the gas peddle. When in lockup the response is more like a manual transmission.

You can see from the pics that lockup makes a big difference. In cabin noise, ,mpg and transmission heat.

The good news is I'm finally realizing I'm not crazy (At least not on this issue).
 

Attachments

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  • lockup.jpg
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When I loose lockup, the pcm is not commanding lockup.
Why?

What are the things that stop lockup from being commanded?
Speed - nope not that
Brake peddle - nope, confirmed brake switch works via pcm pid
Trans temp? -* need to check it *
Load? - nope, light load should command lockup
Closed Loop - nope, confirmed going to closed loop via pcm pid

What else?
 












the motor not ever having to come out again so it has to find another way to piss you off?

Yea, somethings goofy.
Problem is, I'm not sure when this started occurring.
 






long shot again, but i know when mine is acting like that the voltages for the tps are out of whack. does it act like its surging, or does it just not want to lock
 






Thepcm just wont command the lock.
When I am on the hwy and let off the gads I get the tach bouncing a bit as if the tc locks and then unlocks a few times. Kind of a reverse surge? Speaking of which, I'll have to log it and see if it provides a clue.

edit: I just tried uploading my last 302 tune I have on file. I'll drive on it and see if I loose lockup.
 






Datalog

Can you datalog a start from a dead stop going through all the gears?
The "no lock up 2" datalog you sent me looks like it never went into 4th.
May just be me, I am tired from working in the garage all day.
Maybe one right after PCM reset, and one with the problem acting up.
Check your trans fluid?
Trans temp would also be good to datalog.
 



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Is it at all possible there is something in the strategy that is causing this?
Its just so strange that on re-flash, I have tc lockup from anywhere between 1 hour and a couple of days. load maybe?

I'm not hopeful on James being around. I could very well be staring down a decision on either purchasing the pro racer package or going quarterhorse. I'd like to have a look at what kind of options for the tc lockup are in the pro racer package.

Edit: so, on the way home from work my tc lockup starts working on its own again. I have a hard time believing this is pcm. I'll spend some time seeing if I can understand what kind of feedback the trans gives the pcm. If its feedback from the trans I could be looking at wiring or valve body?

I'm still trying to get good logs for 4pointslow to look at that are close mirrors of each other, except for the tc lockup.
 






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