I am having a problem with my a8 signal wire going to the aldl. For some reason it is sending 12volts when key is on. I believe it is suppose to be between 2-5 volts. Does anyone have an idea what causes this problem or how to fix it?

The check engine light will flash codes still but will not send data to a scanner. Keeps saying no signal or no activity. I have tried with and without 10k ohm resistor. I did swap from the old 870 85 ecm to the 165 ecm although everything runs great except for that signal issue.

Any help is appreciated. Thanks in advance.