4L80E dropping into limp mode

[6872xtc]

Well that's not good, but I wouldn't call it toast yet.
Actual diagnosis would be good, however I don't have many ideas past plugging into it with a good scan tool that can do do pressure testing while a gauge is hooked up.
Or maybe drive it with the gauge hooked up to see if it loses pressure when it acts up. I believe that selecting the different gear positions could influence the readings on the gauge. I didn't have to do any diagnosis on mine AND it's been more than a week since I went into mine.

 

[1-ton]

Well that's not good, but I wouldn't call it toast yet.
Actual diagnosis would be good, however I don't have many ideas past plugging into it with a good scan tool that can do do pressure testing while a gauge is hooked up.
Or maybe drive it with the gauge hooked up to see if it loses pressure when it acts up. I believe that selecting the different gear positions could influence the readings on the gauge. I didn't have to do any diagnosis on mine AND it's been more than a week since I went into mine.

This is what I was thinking. Throwing a bunch of parts at it is no gaurantee of fixing it.

 

[TerryD]

Well, it hasn't acted up since I've been home. I've put nearly 100 miles on it test driving both with and without the trailer (empty) and the only thing I can see is excessive TCC slip. It doesn't feel like it slips in any gear.

So I was looking at putting in some parts to help with known deficiencies (TCC valve and the other valve) as well as the reprogramming kit to improve that performance since it looks like I'll have to pull the valve body anyways.

That's my line of thinking.

 

[TerryD]

Is there any good manuals or reading to do for diagnosing these transmissions?

I don't have a full function scanner and there are a lot of parameters I can't seem to access on Torque so what do I need to look for tool wise?

I don't like parts shotgunning but this is new territory for me.

 

[6872xtc]

I have basically no help in scanner suggestions. I have only seen snap-on ones in use a couple of times for trans diag.
It did allow for triggering the pressure control somehow for gauge readings.

And I won't ever say that I haven't had to use parts swapping occasionally. Sometimes the best educated parts swap can help or solve a problem. Could still be cheaper tuition than paying someone else, never know.

 

[Wes Harden]

Yeah what's current price on snap on modus? 10 grand?
I'm just learning my hp tuners equipment but I was lookinging at pids the other day, and the trans pressure pids were there.
I have Amazon Chinese scan tool has some bi direction abilities but I can't recommend it.