no worries.
i've currently driven approx 500 miles since replacing the thermostat.... no DIC warnings or pending ODB error codes.

EinST, was the first to spell it out for me.
Address the ODB code first ( in my case, P0128). fix that and the "ENGINE HOT.." message will go away.
the message on the dash is a bit of a 'red herring'
in fact, we would all be better served if the message just said something like
"SOMETHING IS WRONG, PAY ATTENTION"

there is no particular reason, why replacing the thermostat would be the soluton for everyone but the list of suspects should be short and logical.
-sensor
-connectors and wiring
-thermostat
-coolant level
-control module
-maybe a few others, but no voodoo.

regards,
-bill

 

I called the dealer and the thermostat is covered on the 100,000 mile warranty, so I guess I will let them take care of it on there dollar. It doesn't make sense that they would give a code of P0128 that has an explanation of "engine temp always too cool", and then send the message "engine hot". Leave it to software engineers to confuse that issue.

 

Just wondering if anyone else is hearing a squeaking...like a bad belt when all of the other things with the temp. gauge....and the engine hot notice is going on? Im having the same problems as all of you with the addition of the terrible whining. It sounds like its either the belt or a pulley. Changed the belt but it didnt help.

 

Bought the vehicle....didnt even make it home when this started! Ouch!!!

 

When this happens the auxiliary fan starts up which only runs when the computer thinks there is a high engine temperature. You may have an additional problem of a bad bearing in the auxiliary fan. You will see two fans facing the radiator. The drivers side fan is the auxiliary fan.

 

Just happened on my 2008 4.3 liter work truck which has no A/C. Code read A/C turned off engine hot, and temp guage was not working.....No other warning lights on, and cooling fans were on......Engine ran fine, and did not seem hot, but I shut it down for 5 hours. Same code came on when I started it later, but after driving for 5miles, temp guage started working and message of A/C etc was gone. Truck has only 43k on it, and other than speakers going out, been good truck. Will be talking with dealer, as truck was bought 4yrs and 10 months ago, so warranty may cover bad thermostat.

 

Took Truck to GMC dealer I trust, and there was 12 days left on 5 year warranty. Dealer replaced thermostat. Truck now runs at 210 temp like when new, instead of the 200 temp in last year before problem ocurred. No problems now, and all work was paid by warranty with NO HASSLE!

 

Changing the thermostat fixed it for me

 

...Got the same prob. sure appreciate hearing all your reports! Thanks! Very Much! I'M definitely going to try,' the replacing the Thermostat.' It seems to work from the way it sounds. Man what a great site!
Chevy's rule!

 

Apachegeorge Welcome to the forum

Please do follow up with what you find... works or not as you may save someone else some headaches...