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have done a ls3(24x) with a 4l60e to 4l80e swap,shows code po740 and po785.wont shift into first or od,shifts too quick into 3rd. converter locks up all the time. segment swap has been done and double checked as ok. any one have tips? or advice? Thanks in advance. Wiring in trans and pcm plugs has been done,will be installing new 4 prong brk light switch soon.
Do you have a brake switch wired in the vehicle now for the TCC? Have you double checked the harness rework? Is it possible the harness has been damaged during the installation of the swap?
Was a 4L60E to 4L80E conversion harness used? If so which one? ohm every wire and make sure that they go to the correct pins. I had a conversion harness and several wires were not pinned correctly.
have done a ls3(24x) with a 4l60e to 4l80e swap,shows code po740 and po785.wont shift into first or od,shifts too quick into 3rd. converter locks up all the time. segment swap has been done and double checked as ok. any one have tips? or advice? Thanks in advance. Wiring in trans and pcm plugs has been done,will be installing new 4 prong brk light switch soon.
Both P0740 & P0785 are 4L60E specific codes. P0740 is a TCC Solenoid fault, P0785 is 3-2 solenoid fault. Both are circuit faults.
The 4L80E does not have either of these solenoids!!! I have not done a 4L60E to a 4L80E segment swap personally, I have only been involved in a few jobs that required that process. What I have been told is that when looking at the tune file with HPtuners editor. select edit, then calibration details and you should see 2 controllers.
I have downloaded 2 files to my computer and I will build a segment swap file to look at.
Upload your tune file and i will compare it with the one I am building now.
the screen shots provided to don't give enough data to look at, because you are looking in the wrong drop down menu..
Here are the 2 files I used to create a segment swap file. This will allow you to look at both using the compare file menu.
If you have your tune file handy, you could compare either file to your file. This should help you get to the bottom of it.
I had a 89 Astro van that I put a motor in, the fuel pump went out after about three months. I put a new ACDelco pump in it. Problem solved... about 6 months later it died going down the highway, I put it in neutral, reached over turned the key and it fired right up. Ran for a few months, then died again. Same thing hit the key fired right up. So I started putting ignition parts in it. It kept dying sporadically, I kept putting in more ignition parts, some were under warranty because I replaced cap rotor & wires with the motor. Keep in mind this is the current mom mobile and she is getting frustrated with the van. She's driving around with a loose console & engine cover too. Finally tell her to drive it until it won't restart and Ill come check it. Finally about 18 months after this all started, I get the call. I go and hit the key, sure enough it won't start. I grabbed a spark tester and it has spark!!! Damn it!!! I reached over took the cap off the fuel line and push the valve and I don't have fuel pressure. I towed it to the shop I worked at and ordered a new AcDelco pump. the next day I got ready to push the van in and decide to hit the key. Bang it fired right up and I drove it into the garage. Hour later new pumps in and wife's very happy that I finally found It.. The new ACDelco pump had a burn mark on the side of it.
Moral of the story. Never say it can't be that!! they bite you every time.
So further research into a tune file with a 4L80E segment swap. When looking at code reporting on both files I uploaded. The P0740 & P0785 are still present & checked to report on the second error. I would uncheck the SES enable box and use the dropdown box to make it say "no error report".
in a 4L60E code P0740 inhibits TCC, It does should not force TCC all the time, but who knows when plugged to a 4L80E.
Either way that shouldn't have much effect on the shift solenoids. The shift solenoid pattern for a 4L80E is:
1-2 2-3
1st ON OFF
2nd OFF OFF
3rd OFF ON
4th ON ON
Check your commanded gear and see if they match up. +12v is supplied to pin "E" (to all solenoids except the EPC) & the computer supplies the grounds to the solenoids. Your no 1st & 4th implies that your 1-2 shift solenoid is bad or not getting a proper ground.(keep in mind that a 4L60E solenoid pattern is flipped 4=1,3=2,2=3 & 1=4)
This is where a stand alone shift box comes in handy...
delayed due to sickness in family ,will be installing new brk light switch and go from there. Tuner did say trans would not respond to commands electronically tho. I am new to this and not sure how to send tune.
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4l60e to 4l80e swap problems 
