I have a 2003 Sierra Duramax and the engine light came on and three codes p0700, u2104, u2105 I changed the nsbu and it went off and shifted really smooth for a day or 2 then the light came back on and shifts hard and shifts at higher rpms like it’s in tow mode. Has anybody had this problem or any suggestions? Thanks!
2003 LB7 P0700,u2104,u2105
- Thread starter Jkrug832
- Start date
1) That P0700 means you have more codes in the TCM. Need to find out what those are.
2) The U codes are class2 codes. You've got a communication issue on the can bus. Corroded wires, a bad module or something else.
2) The U codes are class2 codes. You've got a communication issue on the can bus. Corroded wires, a bad module or something else.
I would unplug the tcm bail connections there's two. And dialectical Greese them. Try that first. Use google on how to do that. The tcm is on the radiator shroud driver side