In some instances... having any Class 2 Network "Shorts to Ground" or "Shorts to Positive" happening INSIDE of certain Modules can stimulate the Network to "Wake Up" instead of staying asleep. The mere action of opening ANY Door can cause this to occur if the system has never actually gone completely "To Sleep" in the first place.
General Motors OBD2 Class 2 Networks function on what is called a "Star Topology" where ALL of the Modules are using
One Single Wire actuated by using Pulse Width Modulations that will vary between 0 and 7 Volts DC.
This the Weakness in the Single Network Wire Plan.
If any one or more of the Myriad Modules have broken or frayed wires that are being stimulated when they should NOT be Active... these kinds of phenomena can act like
"The Ghosts in The Machine" as they interact with each other and exhibit these strange behaviors...even to the point of bringing down the entire Network.
Spend some time observing the investigation procedures being followed below in this very worthwhile "Primer on Class 2 Network Diagnostics" and you should be able to use Will Robinson's
*** Approach in discovering exactly which Module is the one actually giving you the trouble.
Please note that even though it presently manifests with the Windshield Washer Motor Odd ACTION here, it does
NOT necessarily HAVE to be related directly with the Tailgate LGM Module... but it
MIGHT be if you DO manage to
PROVE it out in the following manner:
*** Will learned HOW to Solve This Problem courtesy the Instructions and the Training he received from Keith DeFazio from "New Level Auto".