Sunroof Inoperable when Hot Temperatures Outside

[HookEmUT25]

Hi Guys,

I have combed through the various threads here and had no luck in identifying a fix for my current issues with my 2015 LTZ Tahoe Sunroof. As of a month or so (when Summer temps crept up), my sunroof will not open when temperatures are around or over the mid 80's. It functions fine in the morning when still cool but by midday it refuses to open at all.

I'm not sure if this is a weakened motor, lubrication issue, or an alignment issue where some sort of swelling takes place in the heat (it wont budge when I apply upward pressure on the window to try and shift things around to catch a proper alignment). I know the electrical switch is functioning 100% properly and I have located the motor replacement on ebay for $100 but I'm not sure if that will fix the issue.

If I do have to replace the motor is anyone aware of its location or can provide a diagram/schematic for replacing? I believe it is between the homelink buttons and sunroof cutout but not sure how to access and can't find any youtube videos or instructions on the web.

Thanks for any input on this... it's been insult to injury to not have sunroof airflow as my AC condenser has been cracked since April and I still remain on the infamous backorder list for that part. I'm hoping the new condenser has a design improvement so I don't run into this debacle again.

**Mods please move to Interior thread if that is a better fit for this question** TY!

 

[David Smith]

Maybe it is a convenience feature. Your car is telling you that it is hot as crap outside, you don't want that thing open! haha

But seriously, does it seem to make an attempt to open at all? Any movement? Noises? Creaking? Can you see the voltmeter on the dash drop a little bit when you're trying to open it?

 

[HookEmUT25]

Maybe it is a convenience feature. Your car is telling you that it is hot as crap outside, you don't want that thing open! haha

But seriously, does it seem to make an attempt to open at all? Any movement? Noises? Creaking? Can you see the voltmeter on the dash drop a little bit when you're trying to open it?

Haha I agree about it telling me to wise up before trying to open the window in the blistering heat but currently having no AC blows that logic out of the water!

I hear the electrical "tick" sound upon pushing the open button so I know that the signal is being sent to the motor (and like I said it works every time the car is cooled down with no problem at all). When the sunroof functions during cooler times I hear no pops, groaning, struggle, etc on the glass moving along the track and the speed at which it moves is the normal pace. It's as if the motor doesn't have the "umph" or desire to really initiate the glass moving. The motor makes no noise as if it is even trying to begin pushing the glass back when hot outside. Perhaps some sort of safety triggering that interrupts the motor functionality to prevent further perceived damage? I should also say I get identical results whether using the slide OR tilt button (works in cool, not heat).

For $100 I'm tempted to just change out the motor but not sure how big a job that is if it requires stripping headliner, etc. That's why I was hoping someone knew the steps required. At this point I've only pulled down the overhead console to check the wiring but everything is good there and all of the other overhead buttons work fine. Perhaps the motor is just a bit further out of sight but I shutter at the thought of tearing apart the entire roof lining to get to it.

 

[David Smith]

Haha I agree about it telling me to wise up before trying to open the window in the blistering heat but currently having no AC blows that logic out of the water!

I hear the electrical "tick" sound upon pushing the open button so I know that the signal is being sent to the motor (and like I said it works every time the car is cooled down with no problem at all). When the sunroof functions during cooler times I hear no pops, groaning, struggle, etc on the glass moving along the track and the speed at which it moves is the normal pace. It's as if the motor doesn't have the "umph" or desire to really initiate the glass moving. The motor makes no noise as if it is even trying to begin pushing the glass back when hot outside. Perhaps some sort of safety triggering that interrupts the motor functionality to prevent further perceived damage? I should also say I get identical results whether using the slide OR tilt button (works in cool, not heat).

For $100 I'm tempted to just change out the motor but not sure how big a job that is if it requires stripping headliner, etc. That's why I was hoping someone knew the steps required. At this point I've only pulled down the overhead console to check the wiring but everything is good there and all of the other overhead buttons work fine. Perhaps the motor is just a bit further out of sight but I shutter at the thought of tearing apart the entire roof lining to get to it.

I wish I could tell you how to replace the motor, but I have no clue. It just does not seem to me that it would be bad if it works just fine in cooler weather.

Hopefully you get it fixed soon. Still have a few hot months left. Keep us posted!

 

[2011SSVHOE]

check the fuse, I worked at a chevy dealer 30 years ago. had a new corvette towed in multiple times for a no start issue, lots of parts replaced. customer mad as hell. Turned out it was the fuse, It was heat related It was one of them blade fuses had a crack in it that would expand in the heat. crazy but true

 

[HookEmUT25]

check the fuse, I worked at a chevy dealer 30 years ago. had a new corvette towed in multiple times for a no start issue, lots of parts replaced. customer mad as hell. Turned out it was the fuse, It was heat related It was one of them blade fuses had a crack in it that would expand in the heat. crazy but true

I appreciate the input... man that would be great if that was the case! I will give it a shot when I get home and follow-up with the results. Fingers-crossed.

 

[HookEmUT25]

No luck with changing out fuses just now in the heat... still wouldn't open. Tested old fuse in power seat spot and it operated the chair fine. Any other ideas someone can come up with or additional info on sunroof layout/motor availability?

 

[PG01]

I think the rubber is expanding in the heat causing it to stick. next time its open wipe/coat rubber gasket with some silicone lube that comes in an aerosol can, just spray a rag and wipe the gasket and inner metal around roof opening... stop trying to open it the heat before you fix or youll burnnout motor for sure.. my 2 cts

 

[AngelXL]

I'm not sure how this one works but on a Camry. The sunroon got stuck on the open position and I took our the front covert to expose the more and it has an emergency manually key to open it or close it. Check if you can crack it open just little bit.

 

[Danny3737]

I think the rubber is expanding in the heat causing it to stick. next time its open wipe/coat rubber gasket with some silicone lube that comes in an aerosol can, just spray a rag and wipe the gasket and inner metal around roof opening... stop trying to open it the heat before you fix or youll burnnout motor for sure.. my 2 cts

It sure sounds like an expansion issue combined with a weak motor. Is the vehicle out in the sun when it's hot or in a garage? Try parking it in the shade or covered area when it's hot and see if it will open. I would first do what Galante recommended and lubricate the rubber seal with silicone and try that. It could be that the rubber seal is sticking to the glass when it gets hot. Good luck

 

[HookEmUT25]

It sure sounds like an expansion issue combined with a weak motor. Is the vehicle out in the sun when it's hot or in a garage? Try parking it in the shade or covered area when it's hot and see if it will open. I would first do what Galante recommended and lubricate the rubber seal with silicone and try that. It could be that the rubber seal is sticking to the glass when it gets hot. Good luck

Yes, out in the sun because it is sitting at my work parking lot... will give shade parking spot a chance but those are hard to come by around high noon when the temps start getting up there. I will plan to swing by an auto parts store or Home Depot and see if they have that silicone available. Any recommendations on brand / type?

As a side note, I opened the roof this morning and climbed up to see view from top down and see white lubricant in the tracks. Not sure if that's original or prior owner had done that but we've owned it for about 2 yrs now w/o having an issue up until now so it doesn't appear to be neglected or bone dry by any means. Still have no clue where the motor resides or how to access it.

 

[Danny3737]

Try to find a liquid type silicone oil if possible so it can ********* the gasket. Nothing petroleum based since it will eat up the rubber. The white grease is probably lithium grease from the factory.

 

[HiHoeSilver]

Any way that motor has thermal protection and the heat it disabling it? I know the seat motors will shut down for a few seconds under heavy load.

 

[Danny3737]

Any way that motor has thermal protection and the heat it disabling it? I know the seat motors will shut down for a few seconds under heavy load.

If that's the case, then the motor is going bad. That thermal overload should not be tripping when it's only 80 degrees and in sunlight unless there is some type of sliding resistance causing the motor to heat up. You would think that a fuse would blow before the thermal overload protector kicked in. You could always do a amp draw test at the fuse to see if that's the problem. My guess is still that the motor is going bad, but trying to rule out the easy stuff first. Sometimes those gaskets can get gummy and almost glue themselves to the glass.

 

[HookEmUT25]

Any way that motor has thermal protection and the heat it disabling it? I know the seat motors will shut down for a few seconds under heavy load.

This is along the lines with what I was originally thinking it to be but just like Danny said I'm down to try the $5 fixes first just in case. Planning to get the silicone today and give that a whirl. If that doesn't work then I guess I will take a swing at the motor replacement. Thanks to all that have weighed in so far... very much appreciated.

 

[AngelXL]

Motor would be at front by rear view mirror.

 

[Mattwth85]

headliner is time consuming, ned atleast two people to pull it down, another two to load it back in, min as well dyno mat the roof while you have it down, lol......i pulled my healdiner in my 2016 tahoe, make sure your friends have clean hands and get the baby wipes ready to clean grease spots from that headliner.....

 

[Mattwth85]

BTW, my sunroof has been broke for almost a year in mine now, i have no idea what is causing it, i guess i should look at it....i have a 155 db SPL bass build in mine, my brake booster also went out, and alot of random other do dads on my tahoe...brake booster is what is my issue now though, i need them brakes....

 

[Tahoe14]

You have a 2016 and it is not under warranty.

 

[swathdiver]

It's more than likely the sunroof control module. Something in the electronics goes wrong when it gets hot.