What to do about code u0100

Question

U0100 code. Whet do I check. Have good connections

Answer 1

U0100 Loss communication with ECM / TCM

This depends on where this code is from , if U0100 is in the TCM you will go into default gears, If this code is in the ECM you will have a CK ENG LT. Any U code that set may have just set for a variety of reasons, and eventually erase themselves. You need to use a scan tool that will report what module is reporting this code. What ever module store this code , that is the working module , what ever moduel does not report it , that is the faulty module, You do not replace module that report the U codes. Be careful with this code U0100 it may not even need any repair especially if its in the history