2500HD Code U0101 Service Stabiltak light / Transmission in limp mode

Cmcrice89

New member
Jul 4, 2020
3
0
1
Help please!
I have a 2009 2500HD with code U0101 and the services stabiltrax and engine light on with transmission in limp mode. I found leaking internal transmission wiring harness leaking. Replaced it and still have same. Spiral batteries were 9 years old, even though they showed to be still good I went ahead and replaced them. (Figured I can use those batteries in the boat.) Still the same. Tested ground cables from each battery to block ( tested to 0 ohms) cleaned each block location at ground contact, still the same problem. Added additional ground from cab to block, still same problem. I don't have a schematic of the TCM but tested plug at TCM found 2 good constant batteries, and found 2- good ignition batteries. Have not tested to plug at internal harness, does anyone know what pin configuration I should look for at the transmission and can anyone tell me if I need to see more batteries at the TCM? Also how many grounds should i see at the TCM and where in the pin location would they be? Kinda getting to a loss here, any help would be greatly appreciated!!
 

Ron Nielson

Active member
Oct 11, 2009
773
147
43
Berryton, KS
Go to GMUPFITTER.COM, look in the body builder section, then look for your year/model, then look for the electrical manual for your year/model. Not every part of every circuit is there, but most are.
 

Attachments

  • U100.pdf
    163.6 KB · Views: 4

Cmcrice89

New member
Jul 4, 2020
3
0
1
Thanks Ron, all really great information, unfortunately no details for the TCM, or at least not that i could find.