Impala08

I have a 2008 Impala LTZ got the same message on display. After reading the threads here I started with the thermostat, o-ring and new coolant. After I removed the thermostat I noticed a rubber seal pinched in the spring of the thermostat. I haven't had the code come back yet and it's been 2 weeks.

Vince6ft5

I would not dance the happy dance yet. Sometimes it will go 600 to 800 miles before it comes back up.

Impala08

Hey Vince6ft5 only happy dance I'm doing is I can get the car out of Park. Wires pulled loose under console had to buy new "updated" plug. Holding my breathe every day on the thermostat replacement, average 76 miles round trip to work & back.

Impala09SF

I just got this error today as I hit the highway for a long drive from canada to the US. I have a 2009 Impala LS with 3.5 flex engine, car has over 422,000km on it and has been awesome. Still purrs like a kitten, just replaced all 4 strut/spring assemblies, put 4 new drilled and slotted rotors, new premium disc pads (stops on a dime!), 4 new snow tires, turn signal switch (high beams would come on by itself), trunk support strut. It still has original exhaust and engine and tranny has never been opened up. Synthetic oil only and self maintained. Replaced water pump, idler pulley and serpentine belt as a precaution @ 320,000km and loaded new antifreeze. I was debating thermostat, wish now I had done that as well.

Thanks to all for posting info, I think my issue is the thermostat and here is why: when the DIC displayed "engine hot A/C off" I noticed the temp gauge was on "C". I tried the heater (cool morning) and realized it was not blowing very hot air (lukewarm) which indicates either thermostat stuck open or low coolant. I pulled off the interstate and realized my cooling fans were racing away. Checked coolant levels ok. Felt radiator hoses, nothing real hot even after driving 75mph on the highway.

Decided it was ok to drive and continued the rest of the 200 miles to my destination. Just found all this good info, thanks again! When I get home next week I will replace the thermostat and report back. If it gets too warm and I need the AC I will try the reset code bandaid in the interim.

Impala08

If your code comes up you might want to pull over and disconnect your battery for 2 mins. then reconnect. This will clear the code and the fans will turn off. Better to do this than burn those fans up.

Impala09SF

Unfortunately I did not have tools in my car when this happened. I was several hours away from home on a trip.

To update, the next morning I noticed I was getting heat again. I borrowed tools and disconnected the battery, error is gone and all back to normal and has stayed that way for 3 days. I am now home again and purchased a thermostat and will replace it this weekend when I get time.

Chrisimpala35ls

I had a 2007 impala LS, periodically this message would appear and I would lose my ac, and temp Guage would read cold and radiator fans would turn on and stay running as long as that message was displayed but however the engine was NOT running hot. To get my ac up and running again I would pull the negative cable off the battery and let it sit for 2 mins, just enough to reset the computer. Of course this worked especially
On days it was very warm and you need to run the ac, gets very hot here in Florida even during winter season during the day. What would trigger this error or defect was during very cool mornings I would try to run the heat and this problem would occur. I did a lot of researching on the Internet and found that the coolant temperature sensor was the culprit....now to be honest there's actually another culprit involved here also but you will have to determine which one. The thermostat can be the problem also if the temp sensor is working. 2 things happen here when the thermostat is faulty it start getting stuck in the open position position too long OR the thermostat opens to early before the engine is ready to cycle it's temperature for optimum performance or if you try to run some heat in the car. I replaced the thermostat when I did my tune up for the impala so I figured it had to be the temp sensor. Went to auto zone, bought the sensor I think for $20. Located the sensor beneath the throttle body screwed into the block. Disconnected the battery, then the temp sensors pigtail electrical clip, took a metric bolt and ratchet to the sensor unscrewed it and put the new one in, connected the battery. Started the car up and ran all the temperature functions hot and cold. Problem fixed! This is a common issue in the 2006 to 2014 body impala in all engines. 3.5L, 3.9L, and the V8 5.3L.... haven't noticed any issues arise in the 2012 to 2014 LT, LTZ 3.6L V6...... there are a lot of threads on this topic not saying mine is the best but for those of you who have the 06 to 14 body style impala this is the solution and I even included the get by solution which is to disconnect the negative battery cable for 2 mins to get rid of the message and get your climate controls back temperarily. Hope this helps.

Kathilin

I would like to get help with this issue as well. Obviously, it is a problem with the Impalas. When something it a defect in manufacturing, contractually we should not have to pay for the repairs.

Impala08

Mine was the thermostat needed replacing easy fix but may not be everyones problem. Done a lot of research and started there.

Chrisimpala35ls

I'm just adding to the topic once more, ive answered this thread a while ago which you can find if you scroll down all the way and look for my user name Chrisimpala35ls but none the less I answered this thread ( I'm #67 ) when I had the car along with many others before me (07 impala LS V6 3.5) ...here's what's up with that. When you get that message engine hot ac off...here's what's going on either the temperature sensor is not working or the thermostat is stuck in the closed or open position for too long tripping this message. When this happens you lose your climate controls. To get your climate controls back temperarily you must disconnect the negative battery cable from your battery for 2 mins and then reconnect it. The error message will disappear but however this is only works for those cars where the thermostat is stuck in the open position or opens to early before the engines temperature is ready to regulate. I responded once more to this thread because I got an email. Hope this helps. I bought the new 2015 impala and that car is the ****, I absolutely love it.