My wife has been driving her HHR for about 18 monthes now and has started having a problem off and on with her AC. Normally, it cools fine but twice now it has stoped cooling. She still has air blowing out the vent but not cold air. Both times we have noticed that the coolant temperature guage and display have no reading. Acts like it looses the coolant temperature signal. If you let the car sit a couple of hours the AC and temp display come back. The last time we took to the dealer they could not find anything but a service note to apply a software patch to the computer software. Is there some sort of interlock that keeps the AC compressor from running if there is no coolant signal to prevent overheating?

 

Are you saying there's something that adjusts the temp of the A/C based on the outside temp? I've never seen that on my HHR. I often turn the A/C temp down because the outside temp has cooled a little. It never happens automatically.

What's her antifreeze look like? Is it low?

 

No, I was wondering if the computer has and interlock that would kill the AC if the engine coolant temperature sensors failed. I have found several other postings since my original posting indicating that the problem might be related to a wiring issue. The other postings are indicating that similar problems are being reported as being caused by a wire rubbing near the rear of the engine block. The first time the coolant seemed a little low but the second time it looked fine. Looks like a trip to the dealer.

 

I have now lost 2 temp sensors and when they go out you lose the A/C and sometimes the traction control. When first went out it took out dash cluster with it. This one today just replaced sensor and reset computer and its fine now. Only prob with mine so far.