4L80E Limp Mode possible causes?
This is what I have checked
Power from ECU to trans plug
Power from trans plug to solenoids
Varified Solenoid A and B are working and TCC is getting power
Hp tuners shows "correct 4L80E segment swap" no way for me to varify.
EFI connections harness is correct Pin to ECU
NO DTC's reported even when trans plug and Speed sensors unplugged

Trans worked prior to LS1 ECU (TCI box), trans fail from a few feet snapping a small piece of the bellhousing when swapping to a PY3600, which was an easy fix and VERY doubtfoul it hurt any internals.
I verified in my hp tuners scan that the trans stays in second gear constantly (limp mode) I don't know what else to check. ANY HELP IS APPRECIATED.
BTW I called and talked to Gilbert at ACE transmissions (vendor here) and even though he doesn't know me from Adam he helped me and that speaks volumes about him. If I need work on this thing in the future he may be the one I call.
I haven't tried to command shifts in the hp tuners software, but when I attempt to manually put it into a gear still nothing, just 2nd.
I appreciate your response.
So technically I haven't tested ECU to trans connector but since the trans wires have power I would think there good?
I emailed Hp tuners support, but they are on Vaction till the beginning of the year. I hope to have someon look at my 4L80E segment swap to make sure its find tomarrow. I have heard the 4L80E can be run on a 4L60E segment, but I don't know the pros/cons.
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I really thought this would fix the problems, any more ideas from anyone.
Could a faulty PCS (force motor) cause this second gear only mode??
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I really thought this would fix the problems, any more ideas from anyone.
Could a faulty PCS (force motor) cause this second gear only mode??
You aren't going to show anything but 2nd until you have pressure.
Last edited by T/A KID; Jan 9, 2012 at 06:30 PM.
Cam I will do a compare with yours and setup my Trans DTC's to be the same as yours.
EDIT or change them to mil on first error (thats how my SD tune is setup to fail MAF) thanks Slow
EDIT: Something that I discovered was my performance option was set to "Class 2" which is initially for trucks tow/haul (my segment swap was from a 4X4) I just switched this to "NO Switch" (f-body). Doubt this would an issue, but getting up early to see if anything changes.
Last edited by T/A KID; Jan 9, 2012 at 09:19 PM.
Really? This is interesting to me, when you say first gear was yours really stuck in 2nd gear limp mode?
EDIT: Something that I discovered was my performance option was set to "Class 2" which is initially for trucks tow/haul (my segment swap was from a 4X4) I just switched this to "NO Switch" (f-body). Doubt this would an issue, but getting up early to see if anything changes.



