My 2006 Chevy impala dash readout says Engine hot ac off. What does this mean Dealer fixed the thermostat and still is running the same?

Answer 1

This is a copy of my other posting.

This is what I found out. The engine is not overheating. What is happening is that the temperature sensor is not reporting the information correctly, which cause the computer to assume that the sensor is not working and go into default safe mode. Check the temperature gage. It is probably reading zero. In order to prevent overheating, it shuts off the AC and turn on the radiator fan full speed.

I had thermostat replaced which did nothing for the above reason. I don't even know why the dealership even tried to do that since when the temperature reading is zero, it is not the thermostat. Thermostat replacement should only be needed if the car is actually overheating. When I took it in next time, dealership was instructed by the GM tech center not do anything until the new computer calibration becomes available. What they explained to me is that when the sensor gets old, the data signal gets weaker. The new calibration is to be able to read the sensor, even if it starts to send weaker signals. After about a month, it became available. That was last week, the week of April 27th, 2008. There is, or will be a new service bulletin for this.

I got new calibration yesterday. I will be observing it for a while. I drive about 3K per month so I should have a fast longterm info. You should be able to get this done free of charge by the dealer.

I hope this actually solved the problem. Unfortunately, my problem was intermittent so it is hard to tell if this worked.