2019 Mazda CX-9 exhibiting overheating on hot days in stalled traffic. Certainly an abnormal condition an giving this alert ... "Excessive Engine Temperature: Engine Output will be Limited"

Any number of things could have failed - fan, thermostat, water pump, air pocket in coolant system, low coolant pressure, blown head gasket. The dealership wants $2,200 to repair with $1,200 in parts which includes the entire fan assembly. Intuitively, I suspect not all these parts have failed. Can anyone advise if fan parts can be purchased separately? I suspect only one part out of the entire assembly has failed. Any experience here?

 

The Stealership will do that, its probably one of those things listed above. Sounds like maybe the fan is comming on. Could be a bad ground wire, relay or fuse going to fan. Those are easy to check with a volt meter.

 

check out this thread about his fan not working.
https://www.mazdaforum.com/forum/maz...n-issue-50005/

 

Is the coolant level in the reservoir in normal range? If it is low, check the back of the engine for a leak from a crack in the cylinder head. If so, get to the dealership. Carry extra water on your way to the shop.

 

There is not much to really guess on from the information in your first post. But the one clue is stalls on hot days. This would suspect the fan operation. But without a little more detail and first checking the basic's we all could guess at the dozens of posibilities.

 

The coolant level would be the thing I would be most curious to find out. The last thing on the list would be the fan operation. I wouldn't waste your time going down that rabbit hole. If the dealer is giving you a quote I hope they know what parts they're going to load in the parts Cannon. Did you ask them how they confirm their diagnosis? I hope it's not too obvious I don't trust dealers. (Yes, you heard that right, ALL dealers) the only way my car is going to a dealer is for warranty work. Otherwise I'll find a reputable independent shop.