Hey guy's, first post on here, thanks for letting me join.

I have actually looked around the www and lt1swap for hours and haven't found much for help with my situation.

1994 gmc Sierra z71 obs
2004 gmc Sierra 2500hd engine/pcm/harness *!!FROM 2WD TRUCK!!*
2003 gmc Sierra 2500hd manual shift driver side drop t-case and 4l80e

I swapped a 2004 gmc 6.0/4l80e into my half a million km 94 gmc z71. I used dirty dingo mounts and it went in and fit very well physically. Fired up first try after deleting vats. The transmission will not shift out of second though, I am generally good with wiring but have triple checked that already anyway. The pcm tuner rarely does anything with gas engines but does alot of diesel emissions stuff, so him not knowing what he's doing may very well be part of the issue. He was busy and only said the tcc doesn't work and it threw a few transmission codes. But when i drove it before i took it in i could be going along at 20km and pull it down to 1st on the column, it felt like something was very slightly happening like a downshift or tcc lockup. Can someone please tell me what all needs to be turned off and changed on hptuner so i can pass the info on to the "tuner" and maybe get the problem fixed. I don't have hptuner to use to find out for myself and i don't want him to change something he shouldn't. I will post the dtc's when i can go get them from the truck later today.


-I have power at transmission fuse and the plug at transmission
-Speedo appears to work fine
-Neutral safety is a ground signal and is hooked up to the switch on the column and no trans mounted prndl switch is present
-pcm model #E36
-Fluid is fresh and at the correct level
-pcs ground is @ green #8
-pcs signal is @ green #6
-sol b is @ green #47
-sol a is @ green #48
-power is @ fuse box w/15A fuse
-temp sense ground is @ blue #53
-temp sense signal is @ green #51
-press sw a is @ green #63
-press sw c is @ blue #18
-press sw b is @ blue #17
-tcc pwm is @ green #2

Does the aluminum backing plate on the tac module need to be grounded?

I greatly appreciate any help and will e-transfer some $$$$!! to the person that gives the winning answer/help. I need to get back to work!!