U0101 issues

[Sethdavis09]

Have an 05 lly, had wires on the grey (c2) tcm plug with 4 wires rubbed through. Patched it up and still same issue. No tcm communication, no speedo, hard shift into d/r, stuck in 3rd, no gear indicator.

Have power and ground to tcm, plugged another in and no difference. Unplugged all trans harness and engine bale connectors to no help.

Am I over looking a simple fuse or something that got shorted?

Have communication with ecm but not much else.

 

[Ron Nielson]

DTC U0101 00: Lost Communication With TCM

This can be very hard to find where the problem is, but usually easy to fix the problem, ie broken wire, bent pin, etc

 

[Chevy2005]

you might check the IGN 0 fuse in the engine bay fuse pannel