First time poster! 2016 technology model with sunroof. Our vehicle has had the headliner repaired under the tsb bulletin in 2020 and the problem persists with the windows fogging up whenever below 0 c. No water on mats We are not recirculating the air. We have used silicon gel bags to no avail. Any suggestions? Thanks
I'm going to suggest that you might not be having enough heat coming out to get rid of the condensation, only a possibility mind you, and you would come under the TSB problem. Notice the third possibility for the TSB to be needed, Poor heater performance: https://attachments.priuschat.com/attachment-files/2021/11/215475_Coolant_Leak.pdf
Thanks very much, I will definitely bring this up with the new dealer I am taking it to this week. My wife suggested she thought the circulation may be the issue and this seems to cover this.
Have you checked the air filter? Maybe the filter is clogged so there’s not enough air flow. It’s behind the glovebox.
Fog on windshield has always been a problem on all my cars, during the winter. I try to keep the cabin dry but, it's almost impossible to not have at least a small amount of snow on floor mats. Fortunately, I found a small trick to reduce the amount of fog. You have to keep the windows clean. I wash them with Invisible Glass every 3-4 weeks. It make sense, condensation need a sticky surface to cling to. A clean and smooth window doesn't provide a good enough surface for it to stick.
Interesting, I will try the window clean technique also, thanks. I have owned multiple cars and have never had the amount of condensation that this car has, there is something seriously wrong and I am thinking it has to do with the sunroof that as I understand it is not common in the Prius. When we bought it this version with the sunroof , heated seats , etc was only available to dealers in Toronto, Montreal and Vancouver in Canada in 2016. We live in Ottawa so bought from a Toronto dealer.
I read here at PC about a year ago that Power Mode doesn't cycle the heat. I've switched to Power Mode whenever I run the heater and I haven't had nearly as much fogging and the frost on the lower windshield from using the Primes heat pump to heat the car in EV mode and than after sitting all night - is gone completely. I'm not sure that is going to make much sense unless you've seen frost on the bottom of the windshield inside just above the defroster outlets in your Prius..
Will try that and see if it makes a difference for us. it has become much milder in the last day so probably won’t have any condensation now until fall kicks in.
Update : Dealer has told me that the pump that is supposed to bring fresh air in was broken so the inside air was constantly recirculating . This he feels is the main cause of the condensation. Ordered a new pump and it will be installed . He also noted that the sun roof was not sitting perfectly flush and allowing “more water to enter” then the norm. This will be adjusted also. Thanks for the all the helpful suggestions, it was useful .
