Most likely this is going to be the dash harness, but can you let me know which module you are unplugging this from? I am not sure what the park ECU is so do you have a part number or a little more detail as to what this is?
As for this issue, I would suggest we start with checking the codes and finding out what is there.
https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing
The fact that the power steering is operating when the light is not on sounds like a control module issue, but we should have some codes that will point us in the right direction.
Just unplugging this module does not mean that this harness or module is the issue so let's start with this info and we can go from there.
Thanks
Monday, April 4th, 2022 AT 6:42 PM