Question

2003 Cadillac CTS with code U2105, what is the problem with the code?

Answer 1

U2105 Can bus error ECM

U2105 will be set if the TCM has lost communication with the ECM, Each of these modules send information high , low  pulse with each other over a can bus line, If the TCM has not received ECM data for a specific amount of time DTC 2105 will set, Loss of communication can be from the can bus line being open, short to voltage, to a faulty ground on either module

Answer 2

U2105 Cadillac Code - Lost Communications with Engine Control Module
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