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I hope this is the right way/place to post first timer here.
i have a 5.3 4l80e(all stock) swapped 1964 galaxie wagon with psi conversion harness . Everything from the swap was from the same matching 04 yukon except the 80e it was in a running/driving 03 van. I had the ecu tune done local. The issue I'm having is the trans will shift 1-2-3 and over driver very early causing jerking,lugging of the engine then won't shift down threw the gears when I come to a stop almost stalling. Codes that come up are p0650,p0740,p0785,p0856,p1689,p0856
had the tune re checked and he said it's fine must be in harness. Psi checked harness and is saying it's in the tune a few of the codes it has thrown shouldn't even be there for a 80e swap. Any info or tips to solve this issue would help a lot problem has been going on 3 months now
has the local tuner successfully tuned a 80 swap before? did he do a proper segment swap and not just select 4l80e in the drop down menu? you probably cant but if you could post the tune would help.
the only reason i can think of at the moment for it shifting through all the gears that fast would be having the wrong reluctor count for the trans. without having the tune though its gonna be hard to tell what is wrong
the tuner is a well known tuner in sc and says he has done 80e segment swaps. but he did send me a picture of his lap top screan with just a drop down menu that said 4l80e. that being said that may be the case if there is more to it. psi conversion said some of the codes i have should have been deleted and not showing up for and 80e and i need to buy there ecu for 200 bucks which would be fine if i knew that would fix the issue but i do not trust a sales person.
well let me ask you this? how did the tuner successfully tune the 4l80e with all those codes? and if it is indeed in the wiring harness how was he able to tune it? see my point here. i cant see him being able to tune it if the wiring was wrong on the harness. the 5.3 setup you had had a 4l60e behind it and if that specific ecm did not have the programming for a 4l80e then a segment swap was needed.
and yes a tci stand alone controller would probably solve any issues with wiring or tuning from the ecm. it is not hard to trace the wires and see where they go. I have a diagrahm for a 411 ecu that tells you what wires go to what pins on the ecu and you can follow that and do a continuity test to see if there right.
I see your 4 hours away from me. If u are interested I could tune it. Ive done plenty of 80e swaps without issues. Are u using a 4 prong tcc brake switch with your swap? 1 or 2 of those codes are nothing serious and should have been disabled completly
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4l80e issues 
