P0599 Thermostat Circuit High. Anyone else have multiple t/stat failures?

[Ponchoguy]

We had two hot days in NYC this past week and I turned the AC on for the first time this season let's say towards the end of the trip. I have the P0599 code which is probably going to be a t/stat replacement. This is the second time this has happened. About a year ago, the t/stat was replaced by the dealer.

I do all the maintenance on the car myself and fortunately, after much complaining to GM, I have a comprehensive coverage letter on file that covers virtually everything for 10 years/110.5k miles/through 2021, so on a flatbed it will go and back to the dealer for repairs.

Anyone else go through the P0599 rodeo more than once? This is a 2012 LT sedan, 1.8L auto with about 53k miles on it.

The Sonic is not a bad little car, but I must say this was not GM's best effort or foot forward.......

 

[Aftermath86]

I've had my '12 lt sedan for 154k miles. It's odd that the thermostat housing would fail twice (!!!) during a third of that period. We have the same setup as most lux German brands (Audi, Mercedes, BMW) and they don't fail easy. Do you know if the dealer did a ground/open wire/loose connection check before they changed out the whole stat housing? Personally I would look at the switch in the first box, the wiring going to the housing from the ECU and the physical connections themselves for looseness or corrosion.

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[Ponchoguy]

I've had my '12 lt sedan for 154k miles. It's odd that the thermostat housing would fail twice (!!!) during a third of that period. We have the same setup as most lux German brands (Audi, Mercedes, BMW) and they don't fail easy. Do you know if the dealer did a ground/open wire/loose connection check before they changed out the whole stat housing? Personally I would look at the switch in the first box, the wiring going to the housing from the ECU and the physical connections themselves for looseness or corrosion.

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I'm not sure what they did the last time other than change the t/stat, but the CEL went off (and stayed off) since the last t/stat replacement. I consider it their problem as it's under warranty. I just do the maintenance on my own, let them handle the rest, since it's covered .

 

[Aftermath86]

I'll drink to that! As long as Chevy wants to remain responsible for it, let them. Good luck!

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[Ponchoguy]

I'll drink to that! As long as Chevy wants to remain responsible for it, let them. Good luck!

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Thanks, we'll see!

 

[Smartdave]

I have 145k on the clock of my 2012 1.8 m/t.

I am on my second t-stat. First one went around 80k and I just replaced it last weekend. I get them for about $50 and they take 10 mins to change.

So they do go bad.




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[Ponchoguy]

2nd T/stat in 53k miles

This would be the 2nd t/stat in 53k miles. Dealer just called to confirm a few minutes ago.......got it back today and it was indeed (according to them) a thermostat.