I have a 5.3 l83 with a 6l80 with 20 000km out of a 2014 GMC Sierra with factory ecm swapped into a 08 Jeep Wrangler. I'm using a swap kits from Motech which included a harness that blended Jeep and GMC together with there Mocan can-bus module.
Randomly the PRNDL gauge will sweep and also the i-Gauge i'm using will indicate it's going into neutral.
Also I do not have Rev lights.
I've been working with the manufacture of the kit but he's not a transmission guy. I've dropped the pan, changed the filter, PRNDL switch and fluid. The fluid was clean and so was the magnet consistant with something with only 20 000km. I've double checked all the grounds, and the 4 pins going into the Jeep ecm for the trans side. I did notice there is no accessory power to the 6l80 TCM code p2537 but being told I do not need it and to delete the code. I've pulled the tcm connector and it holds in rev and 3rd so I think mechanically all is good.
How can I test to see if this is being caused by the TCM, ECM or the Mocan module. The can-bus voltage and omhs are good. It feels like it's being told to go into neutral for a second or two then goes back into gear.