Infiniti Q's AC Failure: Temperature Sensor Mystery

Hey there! I had a similar issue with my 2017 Infiniti QX30 last summer. I've got some experience working on cars, but when it comes to AC systems, I prefer leaving it to the pros. The symptoms were exactly like yours AC blowing warm air and being unreliable. Turned out it was a faulty connection in the ambient temp sensor wiring. My trusted mechanic found a damaged cable and connector that was causing incorrect readings. Total repair was around 95€ mainly labor costs since they had to access some tight spots to replace the connection. Quick fix, but definitely needed professional tools and expertise. Been working perfectly since then! What's your car's mileage? And have you noticed if it happens more during specific conditions (like after the car sits in the sun)? This info might help pinpoint if we're dealing with the same issue.

Thanks for sharing that experience! Mine's got 36997 KM on the clock and had its last service about 2 months ago. Actually, I've noticed it happens more frequently after the car's been sitting in the sun for a while, but sometimes even on cooler days. Your repair cost sounds pretty reasonable I was worried it might be something more serious like the compressor. Think I'll take it to my local Infiniti dealer first to get it properly diagnosed. Just hoping it's a similar simple fix like yours! Did your mechanic mention how long the repair took? Planning to get this sorted before summer really kicks in.

Hey again! Yeah, I can totally relate to wanting to get it fixed before the heat hits that's exactly why I rushed to get mine looked at last year. To answer your question about repair time: in my case, the whole thing took about 2.5 hours. My mechanic had to remove some panels to access the wiring harness near the sensor you know how these modern Infinitis are packed tight! But since your symptoms sound identical to what I experienced (especially that bit about it acting up after sitting in the sun), I'm pretty confident you're dealing with the same issue. Just a heads up though while the dealer might charge more than what I paid at my local shop, they'll have the specific diagnostic tools for Infiniti models. Since my repair, I've had zero issues with the AC, even during those scorching days when my QX30's been baking in the parking lot all day. Would be great if you could update us once you get it checked out. Always helpful to know if these issues are becoming a pattern in our models!

Thanks so much for all that detail! It's really reassuring to hear that your fix was relatively quick and has held up well. You're right about the dealer probably charging more, but I think I'll still start there just to be safe. The 2.5-hour repair time doesn't sound too bad either at least I won't be without my car for days! I'll definitely post an update once I get it checked out next week. Really hoping it's just the sensor connection like yours. You've been super helpful with all this info, and it's put my mind at ease about the whole situation. Thanks again for taking the time to share your experience this is exactly why I love asking our Infiniti community for advice!