Who says it's an issue? oke: I use that feature to get better fuel mileage...
Ok, ok, if you don't like it, you can have it written out in a custom chip. they usually only do it in a tow program, but they can do it in any program.
I would NOT de-pin or disconnect anything from the PCM, but that's just me.

 

i believe it'll actually get WORSE fuel mileage if it unlocks while slowing down... it seems like while slowing down it throws in BARELY any fuel at all... just enough to keep the engine running... but when it unlocks it has to throw in enough fuel to keep it idling, with no momentum keeping the engine spinning with the TC locked... if i watch the PW on my scan gauge (not the best indicator for this) it'll never go above 0.4ms if the TC is locked while slowing down... if i let it unlock it goes to 1.0-1.1 for a couple seconds when it first gets to idle then drops to like .8 i believe... not really sure cause it's been a little while since i payed attention to that stuff... just my $.02

 

LED brake lamps will cause the same issue. The same with the ABS sensor in the differential case. Any added resitence in the wiring as well, the computer reads voltage through those systems for converter lock up.

 

Yes a chip will fix it, or getting your computer reflashed to the TDE1 code, which has much better shifting and TC lockup and holding.

Dave

 

Like Dave said the TDE1 stock calibration has much better TC lock logic. If yours is already a tde1, and during deceleration you have touched the brake and the tc unlocks but you want it to kick back in, just blimp the throttle and it'll lock back up down to the stock mph unlock speed....

Yes, I have the TDE1 calibration. BIG improvement over what my truck came with. Just seems like it should stay locked down to a certain MPH instead of coming off with the brakes. Also like I said, with the brake lights unplugged at the pedal, it performed perfect. I may play with it more when I get some time, but it sounds like the real answer is to get a chip.

Sorry, Shawn. The bad news is that there are no 94.5-97 PCM codes that actually allow what you want. A new chip will not solve your problem, no matter what box code base is used. TDE1 is as good as it gets as far as torque converter use is concerned.

 

Like Dave said the TDE1 stock calibration has much better TC lock logic. If yours is already a tde1, and during deceleration you have touched the brake and the tc unlocks but you want it to kick back in, just blimp the throttle and it'll lock back up down to the stock mph unlock speed....

 

Yes, I have the TDE1 calibration. BIG improvement over what my truck came with. Just seems like it should stay locked down to a certain MPH instead of coming off with the brakes. Also like I said, with the brake lights unplugged at the pedal, it performed perfect. I may play with it more when I get some time, but it sounds like the real answer is to get a chip.

Shawn

 

My chip keeps it locked up even if I tap the brake pedal lightly several times.

Dave

 

Heck I am looking for a tune where it lets the convertor un-lock on a downshift if the brake is not applied.

Tom

 

What exactly do you mean? The converter to unlock to be used like a downshift or the converter to unlock simultaneously with the downshift?

If the later that's going to be a huge RPM jump.

 

Not only that, but the PCM may be commanding .4ms of pulsewidth....but the injectors take 6-7ms to actually open because of the armature/solenoid/plunger action. That's why you don't hear the injection events during decel at RPMs above 12-1300.

 

yeah i figured i was missing something, that's why i mentioned that it's not the best indicator of fuel consumption

 

Exactly...there is no way to "program" an OBS to keep the TC locked once the brakes are applied. Well, short of killing the brake switch input to the PCM but the cruise will not disengage with a tap of the brakes.

 

Thanks, I got it now. Are you positive the PCM uses the brake input to cancel the cruise? The wiring diagram shows the "brake lights on" signal going to the cruise control outside of the PCM. That switch on the front of the master cylinder is also used to cancel the cruise.

If the cruise is canceled outside the PCM, the idea I have of removing the brake light input to the PCM may just work. And potentially work better than forcing the T/C to engage with a manual switch outside of the PCM control. If this mod works, the PCM would maintain full control of engaging and disengaging the T/C. The only change would be it wouldn't disengage when the brakes are applied. Probably put a switch in line too.

With regards to the "which option would save the most money discussion," there would be less brake lining wear with the converter locked.

Shawn

 

I would like the convertor to just momentarily unlock on a 4-3 or 3-2 downshift. Something to ease that up a bit.

 

To each their own, I guess. I HATE TC unlock during a downshift...what a waste of time and power to the ground.

 

Actually the time when it annoys me is when you are just slowing down enough that it shifts on its own in basically a coast mode. Under power it is better.

Tom

 

You could probably have your downshift point changed (lowered) when there is no throttle input so that it doesn't downshift so early and then you would never know that the TC is staying locked since the RPM rise at downshift is in such a low RPM range.

 

I'm going to have to say that I don't know. Short of turning off the cruise and unlocking the torque converter, that is.

 

.i search for threads pertaining to issue i mite be having and read for solutions i posted because i have a 94 f350 7.3 idi auto trans that every time i let up off the throttle it felt as if od was coming out or was shot or burnt up in my trans and after it taking 2 months of research i discovered in a thread that another man asked if tach would drop to 0 when u let off of the fuel....then he went on to say that speed sensor working cause speed odometer says 45.mph and when faulty tach dropped to 0 the pcm was figuring truck is doin 55 in drive and truck not running cause tach says 0 therefore pcm put trans in limp mode so would not tear trans out.

 

this thread hasn’t been active since 2009 please start a new thread for help. Also please try to use some punctuation it’s very difficult to read your post. Thanks.