BookMark

I have a 2006 HHR LT with 13k miles. My temperature gage no longer registers and my AC stopped working at the same time. The check engine light came on at the same time. Diagnostic states a thermostat problem but I am not overheating. I suspect a fuse or relay problem, but no luck tracking that down. Any advice?

843de

to the forum BookMark!

You don't necessarily need to be overheating to have a thermostat problem, but more than likely what you have going on is a bad temperature sensor, when it goes the ECM/BCM lose that data stream. You gauge and DIC won't register a temperature and the A/C will not engage because there is no temp info being received by the modules.

Even though you only have 13k miles on your HHR, you are do for a coolant change since the DexCool is only good for five years, it would also pay you to change out the thermostat too.**

**Because getting any trapped air out of HHR cooling systems is such a bear, and trapped air can lead to overheating and blown head gaskets. I always recommend you have the cooling system serviced by your dealer or a competent radiator shop with the equipment to evacuate any entrained air in the system.

BookMark

Thank you so much for the information! Since my post, I discovered a battery and 50 amp fuse below the floor panels in the cargo area. I pulled the fuse, replaced it, and my problem seems to be solved for the moment. I will heed your advice and service the cooling system, but, my new question is: why do I have a battery in my trunk??!?

Breadfan

That's where the car battery lives on our HHRs, not under the hood.

843de

Yup, its back there for weight distribution and the plain lack of room up front.

It is a special externally vented battery, they are a bit salty come replacement time, 5-7 years is the average lifespan on one.

You'll know when it starts to go bad, HHR's just act weird with failing batteries or low battery voltage.

whopper

Thermostat is stuck in an open position causing a slow warm up. Pulling the fuse will reset the condition, as will disconnecting and reconnecting the battery. Eventually the DIC will throw a code, along with the blanked out temp display, and the a/c will be disaabled.

It will be an intermittant condition until the thermostat is replaced.

whopper

Check this for further information - https://www.chevyhhr.net/forums/how-tutorial-library-21/how-save-%24350-00-thermostat-replacement-2-4l-p0128-24493/

Oh, and what was the code you got earlier?