Hi guys,

My HHR just quit telling me the coolant temperature. The gauge is parked on the bottom and if I toggle the info panel (IDK the proper name) then I'm greeted with ---F. There is no check engine light so I assume there is no code but I will check this weekend. Car works fine otherwise. No other strange behavior. Is it just a dead sensor? Should it trigger a check engine light if it was?

Thanks in advance!
Krisz

 

You have to replace thermostat

 

From what I read in another post if the thermostat is bad you get a CEL. And even then shouldn't I get at least some sort of temperature reading? I always have the coolant temp on the display and I always had a temp reading after starting the car when the cluster started up.

BTW what is the normal coolant temp? Mine was fluctuating between 190 and 200 in stop and go traffic.

 

Normal temp , 180 degrees, and yes you need to change out the thermostat
Only use an AC Delco 131-158, trust us we know why.

 

The code may just be a current code not setting the CEL. P0128, might be hiding in there.

The other possibility is the temp sensor. That would be obvious if there is never a temp displayed.

The reason for the code is NOT warming up fast enough. It has absolutely nothing to do with overheating.

 

That's within range for stop and go. About 180-185 highway. Depends on outside air temp also.

 

see post #3 - https://www.chevyhhr.net/forums/prob...d-links-38985/

 

Thank you, all, for the help!!
My coworker had his OBD reader with him so i was able to take a look at it:
First I checked the #9 fuse which is not a fuse but a diode. It's working fine but A/C is not. No surprise there.
Checked for fault code -> There is none logged in the computer
Checked coolant temp -> OBD tool can see it so the sensor is working however it seems a bit slow to rise but i was only able to do one very slow lap on the lot so that doesn't necessarily mean something is wrong.
I also cleared the codes for good measure but there's still no temp shown on the cluster.
Question:
On my BMW the temp sensor actually has 2 sensors in it. One for the computer and one for the cluster. Is the GM one a single or a dual sensor?

I have 1 more hour to survive at work. I will pull the red fuse at the battery to clear the computer as someone said in the thread whopper suggested to read (Thanks!!!) and we'll see if that brings back the temp reading at least temporarily.

 

It's only going to set a code if it doesn't reach operating temp in the time the computer allots. This means if the coolant is even a little warm when you start the engine, it may not set the code. Restarts may not set the code. Perhaps warm southern California weather keeps the coolant warm enough when parked, so that it may not set the code.

 

But the computer clearly sees that there is a problem as it shut the A/C off and I have no temp reading on the cluster. So why it doesn't say something about it? (just a rhetorical question)
In my crystal ball I can see the thermostat coming out this weekend...

Wait for it.....

Wait for it.........

Crap! That's me pulling it out....... :-(