GMC Savana Total Window Failure Needs Expert Diagnosis

Had a similar situation with my 2018 GMC Sierra last winter when all power windows stopped responding. Initial diagnostic also pointed to the window regulator but after thorough testing it turned out the main window control module was the culprit. The window regulator motor itself rarely fails on all windows simultaneously. When the main control module fails it affects the entire window control system at once. A proper automotive repair shop should test both the window regulators and the control module before replacing parts. In my case, moisture had damaged the main control module connections. The repair involved replacing the module and cleaning the window track mechanisms. Not a complicated fix but required specific diagnostic equipment to properly identify the issue. This is generally not a serious mechanical problem but needs proper diagnosis. Having a non-functioning window system can be problematic especially during weather changes or at drive-throughs. Getting it fixed at a certified shop that specializes in automotive electrical systems is recommended over general repair shops. The good news is GMC window systems are fairly standardized across models, so parts availability isnt usually an issue. Make sure they check the complete window control circuit before replacing any components.

Thanks for sharing your experience. I am facing exactly the same issue with my 2020 Savana. The window mechanism completely failed last month and I also initially thought it was the regulator motor. After testing, turned out the main control module had corroded, pretty much matching what you described. They had to remove the door panel to access and replace the module. The window track also needed some cleaning and lubrication while they were in there. Would you mind sharing what the total repair cost was in your case? Also curious if youve had any other electrical issues since getting it fixed? Always good to know what to watch out for with these window control systems.

Since having my Savana checked by the mechanic, the faulty window regulator issue was completely resolved. The power window switch replacement cost me 200 Euro, but it was worth every cent since all windows are now working flawlessly. The door panel work was straightforward once they identified the actual problem. Like most electrical repairs, the tricky part was proper diagnosis rather than the fix itself. The window mechanism has been running smoothly for months now with no other electrical problems showing up. For anyone facing similar issues, its really important to get a proper diagnosis of the entire window control system rather than just assuming its the regulator motor. A complete check of the power windows circuit can save both time and money in the long run. Good to hear your repair experience matched what I went through. These control module issues are more common than many realize, especially when moisture gets into the system.

Took my Savana to the shop last week and got everything sorted out. The total repair came to 450 Euro including labor, which seems fair considering they had to do a complete diagnosis of the window control system. The technician found corrosion in the main control module just like you mentioned. Since fixing it, all power windows are working perfectly. No other electrical issues have popped up so far. The automotive repair team also cleaned and lubricated all the window mechanisms while they had the door panels off. Really glad I asked here before letting them replace the regulator motor. Would have spent money on the wrong fix. The window control module was definitely the problem, just like in your case. Makes me feel better knowing this is a known issue and not just bad luck with my vehicle.