I've run into the same problem. Temp gauge not working with needle staying all the way cold, also message that says "heat hot/ac off".

Took it to autozone to get the check engine code read and said it could be:
Low coolant
Bad thermostat
Bad coolant sensor

Since it wasnt over heating, and I was getting heat, and the coolant level was fine I got a new sensor and replaced it. Unplugged the battery to reset the engine code and after turning on the car it seemed to be fixed. How ever after driving a few miles it threw the same error code again with the message. I cycled the battery again and it cleared and gauge worked. It again gave the error code/message after driving a few miles.

What can be causing this?

 

Welcome to the forum. They were able to sell you a ECT sensor and thus the AutoZone's free service wasn't free, was it? If the trouble code is P0128, you'll probably need a new thermostat. This assumes there's no other possible diagnostic based on the freeze frame data. See the discussion in thread https://chevroletforum.com/forum/sil...t-light-40712/.

 

Thank you for the welcome. It was free, i didnt buy the the part till 2 days later, after searching the internet for possible solutions, and figured for 21$ it was worth a shot. I'll try replacing the thermostat tomorrow and see if it still throws the error code and shuts off the AC.

 

Also thanks for linking that post. Very informative indeed.

 

Had same problem. Thermostat was the fix

 

[QUOTE=JoeSkeeter;179823]The temp gauge on our Equinox does not register correct all of the time. Dealer says we have to replace the cluster at 700+. I was wondering if there was anywhere to get one re-built or buy a repaired one?

If the cluster uses stepper motors like all the trucks or 03-05 j-bodies it probably is the cluster.

The cluster's were so bad in the trucks that gm extended the warranty period to 10 years.

The gm tech can easily test the cluster; doing a cluster sweep with the scan tool.

Check on ebay for cluster repair services. They will know if parts are availible.

I bought and soldered in new stepper motors for my 05 cav for $30. There are u-tube video's for this and instructions come with the parts.

 

Common problem with these instrument clusters. We repair these and many other instrument clusters at a very reasonable price. Visit Mr. Whizard Technical Services for more information.

 

Had the same problem. Replaced theromostat and it did not fix. Then it started in my speedometer. It is the instrument cluster. Complained to GM about this issue and they said they hardly ever see this issue. I beg you all to complain to them! If enough people complain they may issue a recall like they did in 2006 for the trucks.

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I have the same problem with my 08 Chevy Equinox i changed the CTS and also the connector to the sensor and have coolant in my vehicle. Reset via disconnecting the battery and all seemed to be fine, but also driving a few miles the gauge stops working and i get the engine hot turn off A/C. What else could be the cause of the problem I am at my wits end??? Also already replaced the thremostat

 

Bought my vehicle in 2007 and is a Equinox LT 2007. I did not know that the temp guage should not be below the last mark of cold on the dash. As a result my head gaskget had to be replace only when the vehicle suddenly is telling me to turn off my vehicle and the dash is lighting up with everything flashing and loud alarms going off. The sensor was replaced three times in two weeks after the gasket was replaced and none of them have worked properly yet. The first one did not move at all, the second one would stick at cold and turn the engine off and then on and would go up to the red in hot. The coolant was checked and it was fine. The third one is doing the same thing and the Service Traction will not turn off and the codes will not come up. I am frustrated as I have spent over $2000 on this problem and it is still not fixed. Help and why is GM not recalling the sensor as I have gone through 3 and did not know it was not working when I bought my $46000 vehicle! Any suggestions?! Frustrated!!!