AintQik

iTrader: (3)

Ok wierd problem. 98Z. I got the car as a basket case but it appears to be the born with tranny. It does have an aftermarket stall. The converter is locking up when it should be unlocking and vice verses. Yeah I know. Took it to ECS and Doug looked at it and he cleaned up the tune but it was still acting wierd. Put the TechII on it and when he sent the lock command it unlocked and when he sent the unlock command it locked up. Who the hell knows?

When driving if you hold it at say 55mph it will stay unlocked, then if you take your other foot and tap the brake it locks and the rpm drops. Again, exactly the opposite of what it is supposed to do. Wiring harness appears unmolested but I did rebuild the motor so it could have been pinched somewhere in the process.

Any suggestions? I'm hoping somebody has a place to start. I'm currently digging around to find the wires that control it so I can take a look. If somebody knows offhand yell at me. I'm thinking it has to be wiring or maybe the PCM **** the bed, but at this point I dunno. Appreciatre any input. Off to go lay under the car and stare at a tranny.

AintQik

iTrader: (3)

For reference it seems pin 32, tan/blk and pin 33 brn control the converter. Going to see if anything odd shows up on those pins.

mrvedit

Assuming you can start the car and stop at a light without the engine dying, the converter is not locked at low speeds. So, it is more complex than just the on/off being reversed.
I would start by checking that the signal from the brake pedal is not reversed.
(I understood what you said about the TechII test.)
There is both a TCC clutch solenoid and a TCC PWM solenoid. Just a crazy idea - I have no idea if reversing the wiring to the two would give you those strange symptoms.

slow67

iTrader: (2)

PWM is going all of time, regardless of brake pedal position, or current gear. Also if there are no hydraulic cross leaks, it won't lockup in 1st no matter what your commanding.

AintQik

iTrader: (3)

I reactivated my HPT account and dug my interface out. After hours of uploading all the updated software on the shop laptop (slow as hell) I was able to start looking at the car. The tranny tune is not stock, but nothing changed that would cause this issue(that is apparent). I did however save a stock tune I found in the repository for comparison and trouble shooting.

While datalogging on the way to work I was able to command the TCC sol on and off and it was acutally doing the opposite of commanded. I commanded "off" and the thing locked up and drove normal. For giggles I left it commanded "off" and the car drove right everywhere, even at stops and such locking and unlocking as it should. This leads me to almost believe its electrical. I can't see how a mech problem would cause this. Maybe the harness is fried?

So a few miles from work I unplugged HPT and the car continued to drive correctly. Wierd. I then made sure It somehow didn't command "off" permanently, which I think is impossible, and it showed no command. I then noticed that the 1-2 shift was much harsher. Light throttle would chip tires. Parked and I have not re-strted to see if the change was permanent. Driving me nuts. At this point I would be happy if it stuck and the chirping shifts don't tear the rear or tranny up. At least I can drive on a highway. More to follow.

mrvedit

That sure is a puzzler.
According to slow67, the TCC cannot lock in 1st gear, presumably due to the hydraulic circuits. That explains why the car doesn't stall when stopped.
If the TCC stays locked during shifts, they will be very harsh.

AintQik

iTrader: (3)

Restarted and symptoms are back. 1-2 shift is normal again. Who the hell knows. I'm going to try and load some tunes and see what happens.

slow67

iTrader: (2)

Yes, hydraulics won't allow lockup in 1st gear (unless there is a hydraulic problem).

Add Some TCC status bits while logging to see what its doing also (instead of commanding).

AintQik

iTrader: (3)

slow 67 I'm back on the HPT and trying to see if I can see TCC data in the log. Its been a while.

I'd much rather be working on my 67 by the way.

On the way home from work I was toggling the TCC Sol off to get it to lock and drive normal. Every once in a while i would command the TCC to do something just to see what happened. It always did the opposite of what you would think as described above. While screwing with it, the SES light came on, first time for that. It was P1800 trans component slipping. Very likely becasue i was maually commanding the thing. However, as soon as the SES light came on, the trans worked perfect, with no input from me and HPT. 1-2 shift was again harsh. I no longer could toggle the TCC solenoid with HPT. Anything i did had no effect.

mrvedit

Once the P1800 code occurs, the PCM disables the TCC and commands maximum line pressure, which gives you the harsh 1-2 shift.

AintQik

iTrader: (3)

So, in effect it was doing the same thing as me commanding the TCC sol off. So, what the hell is this telling me? Send the sol off command and the tranny runs like it should. PCM disables the TCC and it runs like it should. Any of you guys read HPT? I can post the tune in it and see if it has something.

The tune is all over the place, but I don't do autos so I have just a little understanding of what I'm looking at there. The more I see this the more I'm confused.

How in the world would disabling the TCC make it lock correctly?

mrvedit

I am as confused as you, I certainly don't have the answer and I don't think Slow67 or anyone else does either. We are just trying to explain the basics and answer your questions.

Yes, I tune with HP Tuners all the time. It is unfortunate that one cannot separate the engine and trans tunes for the PCM. I cannot imagine how the weirdest tune could give you those symptoms.

If your engine is nearly stock, you should be able to use a stock tune for your year. If you post your HPT file, I will also examine it and compare it to a stock tune for the transmission parameters.

AintQik

iTrader: (3)

Oh I know guys and I appreciate any and all comments. Any leads at least give me something to chase and it helps a bunch to hear you guys confirm my suspicions on how the thing works. Obviously frustrating. Lol I love my life, I always get these seemingly impossible issues. One time I walked up to a running turbo diesel and it died and nothing made logical sense in the trouble shooting. Had to study ford theory for 2 weeks to figure it out. You all are helping me study lol. I will get it. Someday!

Dropping the pan tonight just to see if I find anything odd. Like you mentioned I can't really find a table in the tune that would do that.

Maybe the PCM is hurt? I wish I could find one on the cheap to rule that out.

Wonder if I can put a meter on the signal wire and see what is being sent to the tranny when commanded? I think it sends ground, pin 32 or 33 if I remember right.

AintQik

iTrader: (3)

Found this morning that if I command the TCC Pulse Width Mod off, the converter locks as it should. I can leave the TCC Sol alone, just command the PWM off and it also works as it should. Hmmm

mrvedit

"Hmmm" is right.
There is both a TCC solenoid (bolted into the pump) and a TCC PWM solenoid in the valve body.
Not claiming this is "right" or the "fix", but here is what I would do:
1. Drop the pan and replace both TCC solenoids.
A) The TCC PWM is a snap-in.
B) The main TCC soloenoid is wired into the harness; you can purchase a replacement that is spliced in. Any trans shop should have one - the same TCC solenoid is use in the 700R4, 4L60E and perhaps others.
C. While you have the pan off and if you can access the PCM, I would check the continuity between the PCM and the two solenoids because I still wonder if they got reversed.

Not sure if this would work, but since you have a scanner, I would command the TCC lockup and ensure the voltage on one side of the main TCC solenoid drops to 0V. (The red wire side is always +12V).

Alternatively use an ohm meter for real continuity.
On a '98 PCM:
BLUE Pin 32 (Tan/Black) goes to the main TCC solenoid
BLUE Pin 33 (Brn) goes to the PWM TCC solenoid

To connect to the PCM pins I stick in a needle (or a small resistor lead) and connect to it with an alligator clip.

These are just my thoughts; I could be way wrong.

AintQik

iTrader: (3)

That is exactly my next step.

However, while digging around the tune that is in the car I noticed that the max and min TCC duty cycle were both set to "100" across the board. I compared this to a stock tune, and a known good tune for a stalled tranny and they both had "100" as max and "10" as min across the two tables. I doubt its something this easy, but I am going to give it a shot. Only other wierd thing is the tune did not de-sensitize the misfire tables. I also added that and will give it a go. If not, exactly what you described is what I'm doing next.

mrvedit

Lots of people tune the TCC for 100% max and min. It affects how the PWM engages. 100% min basically makes it an on/off TCC which is better for most aftermarket converters.

AintQik

iTrader: (3)

Yup, it had no effect whatsoever. I'm learning lol. If turning the PWM off amkes the trans work right, I guess my next step is to research the PWM and see if there some test procedures, or just swap and pray.

AintQik

iTrader: (3)

Ok, so 1st off I know this is not a fix but it works. I pulled the wire that feeds the PWM (pin 33) and shorted it to ground. P1860 code comes up obviously but i just tuned it out. TCC locks up no problem. Beat the hell out of it and the only issue is it will hit the rev limiter so I think I need to tune a bit more. Otherwise it works perfect.

mrvedit

Congrats on the "fix".
It would still be good to know if this is/was a defective solenoid or PCM problem.