[BYEBYEAMG]

I know this exact issue has been discussed extensively over the years but can anyone synthesize all the opinions and possible fixes as to what is the actual root cause of this very common problem w/ the 2006 model year?

My 2006 STS-V has started to give this warning lately.......even upon starting up cold first thing in the morning.

 

[baller95]

Bad thermostat. It's a cheap fix, should be no more than $50.

 

[Berger 93]

The thermostat gets stuck open . . . the temperature difference between the sensors fore and aft of the thermostat does not change per operating parameters, so the car senses something incorrect and throws a code, unfortunately the system by default thinks it is overheating.

 

[lamrith]

It is Thermostat, seems counter intuitive given the error on the dash, but the car will actually be running cold. The Therm in these cars fail in the open position, so then the car does not come up to temp properly. The ECU sees the car not come to running temp in a certain time frame and thows that error out.

You can get a new Thermostat them for as little as $15 from Schucks/Napa. Tight squeeze, but if you are mechanically inclined you can do it yourself in your driveway, just takes time.

 

[CMNTMXR57]

I was gonna say, bad t-stat. Simple summation.

 

[TimmyC]

The tstat doesn't actually fail in the open position; pieces of the gasket on the plunger get lodged in the seat and prevent the it from closing all the way. I posted pictures of it on here somewhere.

 

[Robert Kimball]

I had the same problem with my 08'. Replaced the tstat and problem went away!!

 

[BYEBYEAMG]

Happy to report that a new Tstat + 160$ f/ my mechanic made the problem go away.

My LC3 also seems to be running a bit warmer in the 190's rather than the 180's under the same highway conditions

Thanx f/ the help