4l80e issues
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
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
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.





