l83 with 8l90 swap not shifting

[honda64]

im new to the swap/tunning community i am currently doing a l83 with 8l90e running a stage 2 tsp cam little head work done. got the motor to fire up goes in prnd but will not shift out of first gear the guy that sold me the motor gave the ecm for a 18 chevy 1500 so i had to find another at the junk yard off a 2014 chevy 1500 not sure if it had the 6 speed or 8 speed in that truck. from what i can tell the t87 tcm is right ive got tach and speedometer trans oil temps seems okay. im wondering if the ecm was configured for a 6 speed and the ecm just needs a tune or is there something else im missing. any info will help thanks
2014 chevy 1500 version 3.hpt

[5FDP]

The 8 speed was not offered until 2015 in the half ton trucks.

That is going to be a 6 speed computer. You need to have that computer flashed with a 8 speed file. You also need to make sure that the calibration that gets flashed to it works with the engine you have. There is a 4 wire high pressure fuel pump on the 14-16's and in 2017 it switched to a 3 wire if I remember right. So from the sounds of it you need a 2015-2016 file for the 5.3/8L90e.

Both the PCM and TCM will want to be flashed at the same time so have everything hooked up when you do that.

[honda64]

ill try that should i obtain a file from tis programming?

[5FDP]

If that is something available to you, that is a way to do it. I guess you'd just need to pick a VIN/OS that would use the file you want and have it flashed into the computer.