We already know what happens.The trans will shift normally through all the gears,only the converter wont lock.Once the PCM has detected the converter hasn't locked a few times when it knows it's supposed to,relative to the speed/tps/rpm (and tans temp from the tot) signals,it will send the trans into limp mode with increased line pressure and the OD light will flash.Stored in the PCM,will be the converter slip code.It may be working for you for a short while but rest assured this will happen.You should hook it back up now that you have a new PCM.We'll probably never know now but my guess is for some reason the old pcm wasn't performing the split second unlock between your shifts.Over time,this wore out the old converter and now off balance,it caused the whole truck to shake during it's locked shifts.....but it's just a guess.
This is why I never encouraged people to put that line on a toggle cus even if it didn't eventually cause the flashing od light/slip code (which it will) is that it's nit a good idea for the trans to shift while locked.People are best off to let the PCM do it's work,like it or not lol.
I love the units in the late IDI diesel trucks (they can't be used in gas trucks cus they are trans only units but they will retro fit all older idi diesel trucks with the e4od.) Very good shift scheduling imo.

 

I don't think its shifting on a locked convertor clutch. Solenoid must open to move convertor clutch valve. No wire, no open, no clutch.

 

Don't cut wires. The wire will pull out of the plastic part of the connector for testing. You have to release the clip on the wire end.

The torque converter lock is part of the transmission design. Continued operation without the converter lock will likely cause problems.

I stick my hand through the grill to check the trans cooler. Watch it for heat.

You're close to a problem free transmission It can still get a little better and it can get a whole lot worse.

 

OK. I am in no way doubting what you are saying. Please don't take this the wrong way. You tell me that i will destroy my trans this way. To what can you prove this? It seems as lf you are telling me that you know of many times cutting this wire tore up peoples transmission. Can you truly say that this was the cause? If trans wasnt actin g up, they would never have cut any wires.Most shops wiil not tell you the exact cause of failure, and most people dont care as long as it is repaired.

 

No, I don't know for a fact. Just saying that the transmission is designed a certain way.

I'm saying that it is likely to cause a problem. But I'm almost certain you won't find a warranty on an E4OD with a slipping torque converter.

Like I said, watch the heat. That would likely be your first clue. Especially if you have to pull a load, watch it close. Watch for heat, watch for codes.

And like I said earlier, I think you can fix it the rest of way, if you want to.

I won't drive an automatic with a problem. I'm not trying to tell you what to do. If it was mine I would park it except for testing.

 

It was shifting on a locked clutch with the wire intact. The PCM is supposed to release the torque converter clutch for a very short time during a shift, but the hardware in the E4OD was really not able to respond fast enough to make this a reliable feature. With the wire cut the torque converter clutch is always unlocked.

It will cause two things: Higher transmission temperatures and lower fuel economy.

 

No one interested in fixing their truck should pay attention! The following is "get you by" info only.Not proper or recommended method of running your E4OD.


Of course not. Not now lol. I was talking about what was probably going wrong with your old PCM and converter. If it's just an "old 200k mile truck" that you want to just keep running into the ground and your ok with running as is without a locking converter,I would probably add a cheap trans temp gauge.You might find you'll need to add a larger aux cooler for it run cool enough (with your temp sending unit in the test port,just don't let her creep up over 225F for very long,get a cooler where it stays around 175F would be best) When the OD light does eventually start flashing and storing the slip code,you can keep pulling over and removing the bat post to clear the code.This will make it shift easy again if you get tired of shifting firm,at least for a little while.
In your case,you might find you'll need a 6.0l trans temp cooler but I dunno.Never run one unlocked long enough to know.When the converter locks though it sheds heat like a bugger,so keep this in mind.

Really though,there's still no reason for you not to put the line on a toggle switch and just return it to oem once your up to speed too.

 

Here is where we failed you: You can reach up with your left foot and tap the brake to unlock the converter. (BOO) switch if you read about it.

Get on a hill, light steady pull up the hill. Hold the gas pedal steady and reach up with your other foot to cancel the lockup. You should see the RPMs rise a little. When you take your foot off of the brake pedal the converter will lockup again and the RPMs will go back down.

What makes these transmissions tricky is that the problems can be electronic, electric, hydraulic or mechanical. You can get side effects, across those lines, and end up with other problems.

If you want to fix it, don't wait too long. Come back and try some tests

 

No one has failed me. Every one has had thier ideas and tests, plus their results. Seems as though when i have a problem it is unique to me only. The strange thing about it, and i never paid much attention to it, is it would shift 1 to 2, 2 to 3rd, 3rd to 4th, and at 42 mph it felt like it shifted again. in 4th gear the TCS did nothing. I am still testing with meters and light bulbs, checking convertor clutch timing. All shows good as of now. I will try your suggestion. Never know.

 

Actually,yes he's right.We do know.If you wanted to re-hook your line,you could keep everything oem and if your getting clean shifts with the converter unlocked,you could do just that instead.Ride the brake just enough to make the brake lights come on until your up to final gear then left off.This would keep the truck shifting as it does with that line cut and then lock the converter when you let off the brake once your done shifting.
That's actually a much better work around cus you'll get no limp mode and flashing od light.

 

Sounds like a short in the wiring or shorted clutch solenoid to me.

Attachment 277397

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I have changed the solenoid pack two times. One was used, which a lot of times is a good thi ng, The other was reman with all new solenoids and printed circuit board. All three were tested w/ ohms reading and operating capability. All three tested the same. The TCC circuit lights the light as soon as 3rd gear is reached and stays lit to 4 th gear. If you push the TCS switch. the light gives a little flash and downshifts to third. Push again, light gives a little flash and shifts back to 4th gear. Only once did it flash by itself when shifting to 4th gear. Brake has same effect as TCS switch. If you slow down in 3rd gear light will go off and come on and off when you push the gas pedal. It only does this in gear. Not in neutral.

 

How does the line ohm out for resistance then? If the line shorts to the frame or somewhere else to ground,it will lock the converter.Your kinda narrowing it all down to the wire between the PCM and solenoid at this point.If the PCM is new and commanding everything good and the solenoid tests out ok,then by default the wire is shorting out as it's the only thing left.

 

That would be anybody's conclusion, except if wire was shorted permanent or intermitent, the light would be on all the time, or flash on and off if short was coming and going.