JX35 Cooling Crisis: Fan Failure or Control Unit Issues?

I had a similar issue with my 2016 Infiniti QX60 Hybrid last summer. The symptoms were exactly the same A/C wasn't cooling properly and engine temp would rise, especially in traffic. Turned out it was indeed the electric fan control unit that was failing. Got it fixed at my local dealer after my regular mechanic couldn't properly diagnose it. The fan would either not kick in when needed or run continuously. It wasn't just an inconvenience if left unfixed, it could've led to engine overheating and serious damage. The repair involved replacing the entire fan control module. In my case, the problem never came back after the fix. Just a heads-up: this isn't a quick repair, as they need to access components behind the radiator, but it's definitely worth getting it done properly. I'd recommend having a dealership look at it since they have the right diagnostic tools for these hybrid-specific issues.

Thanks for sharing your experience! It's really helpful to know I'm not alone with this issue. Mine sounds exactly like what you went through. How much did you end up paying for the fan control module replacement at the dealer? Also, curious if you've had any other cooling-related problems since getting it fixed?

Hey there! Just wanted to follow up on your questions about the repair costs. After getting my QX60's fan control unit fixed at the dealer, I ended up paying 480€ for the whole job. And I've got some good news since getting it sorted, the cooling system has been working like a charm! No more temperature spikes or A/C issues at all. It's actually been such a relief because, like yours, my fan was acting really wonky before the fix sometimes running non-stop, other times not kicking in when it should. The dealer's diagnostic equipment really pinpointed the problem with the control unit straight away. Looking back, it was definitely worth every penny to get it properly fixed rather than letting it potentially cause more expensive engine damage. Just to put your mind at ease I've put quite a few miles on the car since then, and everything's still running perfectly. The A/C blows nice and cold, and the engine temp stays exactly where it should be, even in heavy traffic on hot days. Hope this helps with your decision!

Thanks so much for the detailed follow-up! I finally bit the bullet and took my JX to the dealer yesterday. You were spot on it was the fan control unit. Got it replaced and the total came to about 520€, which wasn't as bad as I feared. The whole experience was actually pretty smooth. Dropped it off in the morning, and they called me by afternoon with the diagnosis. The mechanic showed me the old unit and explained how it was failing. They had the part in stock, so everything was done by the next day. Just picked it up this morning, and what a difference! The A/C is blowing ice cold again, and the temperature gauge is staying perfectly steady. Such a relief to have it fixed properly. Really glad I followed your advice about going to the dealer instead of trying to save a few bucks at my regular mechanic. Thanks again for helping me make the right call. Time to enjoy my properly functioning car again!