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4l80 Converter not locking up

broncoman6524

broncoman6524

1/2 ton status
Joined
Oct 31, 2005
Posts
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Location
chuluota Fl
0411 PCM
Custom harness
LQ9
"96" 4L80E
FTI 3K lockup converter.

Tuner setup converter to lock at 45mph, it won't lockup on it's own. However if he commands it to (using HP tuners) it will lockup.

I've verified my TCC relay is wired properly. Purple 33 has keyed 12V, once brake is applied the power goes away.

Fluid level is correct.

Trans is a junkyard pullout, they told me it worked properly. I'm inclined to believe them, as it shifts phenomenally and doesn't slip.

Where should I start? I presume this is either a tune issue, or an internal trans sensor issue.
 
Someone like EagleMark probably has actual experience with this, but does the TCC use a brake unlock switch like the earlier stuff? Any chance it would cause this issue if not set correctly?
 
dyeager535 said:
Someone like EagleMark probably has actual experience with this, but does the TCC use a brake unlock switch like the earlier stuff? Any chance it would cause this issue if not set correctly?
Click to expand...


It does, that what the part about the tcc relay being wired up properly was about. I spoke with the guy who built my harness pin 33 requires constant keyed 12V, and to loose power when the brakes are applied.

Which is what my statement was about.


No disrespect intended, I tend to speak in a sarcastic manner. :D
 
No worries, really don't know how any of those work, but you did say voltage goes away. :)

Are there any parameters in the PCM that also control lockup? Do you have the ability to look at the programming yourself, see if maybe something was missed by the tuner? Something like a temp setting?
 
my old 96 crew cab when cold wouldn't lock in till the tranny fluid or engine coolent reached 140* .

I would cruse up the road cold and hit the highway . as soon as I felt it lock in I knew it was time for heat.
 
sweetk30 said:
my old 96 crew cab when cold wouldn't lock in till the tranny fluid or engine coolent reached 140* .

I would cruse up the road cold and hit the highway . as soon as I felt it lock in I knew it was time for heat.
Click to expand...

I tried some changes today, let the engine get to operating temperature then drove. Still didn't lock. Trans was below 100 degrees the whole time, this past weekend I ran the highway for 150 miles it built heat till 180 degrees and still never locked.


I personally don't have anyway to track it, I should*** have access to serveral different snapon modus scanners. But before I borrow somebodies 10K$ machine I want to know exactly what to look at and for.
 
Is the brake switch staying open after applying brakes?
 
Did the tuner do a trans segment swap? Or are you using the 4L60E trans segment?

If the PCM is programmed with the 4L60E segment, then the TCC PWM signal cannot be used to drive the TCC PWM solenoid in the 4L80E... you have to use the TCC On/Off signal instead.

There is also a RPM setting to go along with MPH, so adjusting MPH for what you think is accurate does not work with high stall convertors. In EFI Live there is a sanity check built in as you place the cursor over a cell containing MPH, the bottom of the tunetool window shows rpms, look at the rpm for the gear of the table you're in.
 
eagle mark said:
Did the tuner do a trans segment swap? Or are you using the 4L60E trans segment?

If the PCM is programmed with the 4L60E segment, then the TCC PWM signal cannot be used to drive the TCC PWM solenoid in the 4L80E... you have to use the TCC On/Off signal instead.

There is also a RPM setting to go along with MPH, so adjusting MPH for what you think is accurate does not work with high stall convertors. In EFI Live there is a sanity check built in as you place the cursor over a cell containing MPH, the bottom of the tunetool window shows rpms, look at the rpm for the gear of the table you're in.
Click to expand...

He was supposed to have re-flashed it for a 4L80, previously it was flashed for a 4speed.

Interesting part about the RPM/MPH setting, again I don't know and won't know until I get with him again.
 
Lockup command is probably based on RPM, MPH, MAP, tranny and/or engine temp and possibly TPS. One of those conditions must be set wrong for lockup enable. Make sure you know what units they are in.
 
eagle mark said:
Did the tuner do a trans segment swap? Or are you using the 4L60E trans segment?

If the PCM is programmed with the 4L60E segment, then the TCC PWM signal cannot be used to drive the TCC PWM solenoid in the 4L80E... you have to use the TCC On/Off signal instead.

There is also a RPM setting to go along with MPH, so adjusting MPH for what you think is accurate does not work with high stall convertors. In EFI Live there is a sanity check built in as you place the cursor over a cell containing MPH, the bottom of the tunetool window shows rpms, look at the rpm for the gear of the table you're in.
Click to expand...

Is the harness set up for a 4l80? the 4l60 uses a slightly different pinout for TCC and could cause what you are experiencing.
 
Yeah, when I had my harness built I specifically told the gentleman for a 4L80. Upon picking it up he went over the whole harness and showed me the differences between the 60/80 harness.

I just got my HP tuners in last night, I plan to read ALOT then start trying to look into what's going on.
 
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