Here is a question for y’all. I have been having a strange problem with my 2005 GMC Yukon XL (yes I know it’s not a Suburban). I have owned it for about a month now. The issue is the courtesy lights. When I open any of the four doors the courtesy lights come on as they should. However, the truck seems to think the doors close a couple seconds after they are open and the courtesy lights dim out then turn off (like they should if the vehicle is running and doors are closed) even though the doors are still wide open. This occurs even when the engine is off. I have even tried opening the driver door with engine off to see what happens. I get the courtesy lights and the door chime telling me keys are still in the ignition but again for only about 2 seconds then it stops dinging and the courtesy lights go off as if all is well. I do not have this issue with the rear lift gate or glass. The courtesy lights work there as they should. I have searched for a resolution but have only found issues with the courtesy lights/door ajar issue. That’s the opposite of my problem. I have shot the latches with WD-40 just as something to try but to no avail. Has anybody else had this issue? I can see one door sensor going bad causing this issue, but all four?

 

Did you ever figure this out. I am experiencing the same issue. Notice it occurs with the passenger front door and drivers rear door. Thinking probably the door lock modules.