I have a 2010 Pontiac G6 GT Flex Fuel 4-door sedan. The temp gauge in the dash does not work simultaneously, along with the air conditioner is not blowing cold air. I just started this about a month ago. One day they didn't work; the car was turned off and on several times that day. The next morning they work right away. They continued to work fine for about a week or so. All of a sudden, again, one day, they didn't work. It seems to mostly do this when I start my car; however, one day, while driving, the air & temp gauge started working. Usually, though, it happens to work or does not work when I start the car. I just had a new thermostat put on within this past week, thinking it would solve the problem, but it didn't because this morning, both the temp gauge & air conditioner would not work. I would greatly appreciate any suggestions. Thanks!
Sounds like an intermittent ECT sensor (or possibly its circuit). If a scan tool reports the coolant temp to be -36F(IIRC), then the sensor signal has dropped out & the ECM/PCM is substituted with this non-sensical value. Are you getting any codes?
Sounds like an intermittent ECT sensor (or possibly it's circuit). If a scan tool reports the coolant temp to be -36F(IIRC), then the sensor signal has dropped out & the ECM/PCM substituted with this non-sensical value. Are you getting any codes?
Thank you very much for your response, greenman. Yes, I do believe the mechanic said the car gave a code, but I don't recall what. My fiance and I took the car to the shop just last week. Mechanic had faced a similar problem with a pick-up (but not a Pontiac) so I guess figured it could have been the thermostat. Guess the mechanic was wrong though. I am going to let the mechanic know today that it is still messed up. I was just hoping to get some ideas of what to tell him to look for. You sound very knowledgeable; I will be sure to share your input!
The code is critical info to know. It could have been the thermostat stuck open but his scan tool would tell the tale (what the ECT is reporting to the ECM) & he shouldn't be just throwing parts at it.
Thanks, again. I'll let you know the outcome. Hopefully no one else is having this problem, but if so I will be sure to post the outcome for their sake as well!
Hi Greenman ~ So the mechanic put a sensor on my car for the temp gauge and so far all is working well. This was only 5 days ago, but I pray that is all it takes. Sure wish we would have tried this first because the sensor at $38 sure beats what I paid for the new thermostat at $120.00. Thanks again for your help! (now my shift linkage has went out so i'm dealing with that!)
That issue goes back to the 04 Malibu I had with the 3.5. Temp gauge went to zero, code PO116, replaced temp sensor under warranty, came back again and ignored.
Someone posted on another forum that it was a issue with module connection, can't recall.
No, I don't know the exact code, but I do recall him saying something about it being a code that was from back in the winter. I have about 66,000 miles on the car.
We got the shift linkage problem fixed, too, now. Whew - hope nothing else goes wrong!!
i'm having what i believe to be the same problem, about 3 days ago, the temp guage just went to 0 while i was driving, later that night after i got off work, the air didnt work, only 50k on this car, the air worked fine the day before, i already had a check engine light on but hadnt pulled the codes yet, was planning on doin that this afternoon, the thermostat is good i believe as the heater puts out pretty hot air, and even if i rev the car to 3k and hold it there for a while the temp gauge never moves. my question is, where is this sensor(s) located, how would i go about testing it? and is there a separate sensor for the computer and one for the gauge, is is it one sensor for all, i'm trying to help my buddy out, hes loaning me his car for 4 weeks while hes out of town and would be cool if he could come back to a fixed car as hes not charging me to use it, any help would be appreciated.
Hey all. I just wanted to add my experience with this issue. A couple of days ago the check engine light came on, the air conditioner stopped blowing cold air (but still would blow hot air) and the coolant temperature gauge would not rise. The OBD2 scanner threw a P0116 code "Engine Coolant Temperature Circuit Range/Performance Problem". Also if the engine ever warmed up and I tried to start it hot it would have a hard time starting up. I assume that is because it registered the engine as being cold and was therefore was causing it to be too rich? After researching on this site (especially this thread) I decided to replace the engine coolant temperature sensor (was only about $10 and took 15 minutes to replace). That did the trick. I have attached a couple pictures indicating where the sensor is located on my 2008 3.5L. After removing the sensor clip I used a 3/4 inch deep well socket to remove it. I quickly replaced it as coolant started to leak out a little.
So if suddenly you CEL comes on, your temp gauge stops working and your AC stops working you, I would suggest you replace the ECT sensor.
Hey all. I just wanted to add my experience with this issue. A couple of days ago the check engine light came on, the air conditioner stopped blowing cold air (but still would blow hot air) and the coolant temperature gauge would not rise. The OBD2 scanner threw a P0116 code "Engine Coolant Temperature Circuit Range/Performance Problem". Also if the engine ever warmed up and I tried to start it hot it would have a hard time starting up. I assume that is because it registered the engine as being cold and was therefore was causing it to be too rich? After researching on this site (especially this thread) I decided to replace the engine coolant temperature sensor (was only about $10 and took 15 minutes to replace). That did the trick. I have attached a couple pictures indicating where the sensor is located on my 2008 3.5L. After removing the sensor clip I used a 3/4 inch deep well socket to remove it. I quickly replaced it as coolant started to leak out a little.
So if suddenly you CEL comes on, your temp gauge stops working and your AC stops working you, I would suggest you replace the ECT sensor.
So I've continued to struggle off and on with this issue. I ended up buying a new electrical connector and spliced it in, seems to throw the code less often, but still every once in a while. Checked with the OBD scanner and thew code P0128 so I'll replace the thermostat and hope that fixes it. So strange that this has been an issue off and on the past year and a half.
Problem just started up again.
101,000 miles
new temp sensor @70,000
new thermostat @70,000
checked wiring (ohm out the harness with and without stress on it)
Are these sensors $*%t or what?
Haven't put another one in yet.
Anyone ever found a permanent solution yet.
I never heard if the owner who got an ECM flash helped or not.
Y'all no the car I own hasn't been treated well by the previous.
But, I know how to take care of my own.
so to clarify: u were getting a 116 code 31K ago & now it's back?
did u use an oem sensor & was anything used on the threads during install? Have u tried cleaning the harness connector electrical contacts because a little invisible corrosion buildup will modify the resistance in the circuit & change the temp reading by the ecm.
Code 116 doesn't always throw. What happened then and now is temp Guage reading nothing, fans on high, then check engine flagged. Not sure if the code is my usual catalytic code that comes and goes, or if it's 116.
Pulled sensor and it reads resistance perfectly as it should.
I'm outta town for 3 weeks and wife was going to use it. I don't know now. This sucks.
Yes, I used contact cleaner on both ends,
Temp sensor was from Auto zone,
It had factory applied thread stuff. Which I cleaned off after checking it and put on Teflon tape.
Drove it out of town. Runs and drives fine
Temp sensor got replaced 4 days ago. Problem went away, but came back today. Check engine was already flagged (yesterday) for my catalytic conv. Wife has car. I don't think 116 is flagged. Sensors were from Autozone.
So you get all of these exact symptoms: temp gauge pegged at C, AC is disabled & both fans running on high. But you aren't getting any cooling codes. I've never run across that one & don't see how it's even possible. What is the cat code you're getting?
I'll have to run the codes to be sure. Wife has the car for a while. I know for a fact that P116 had come up before when the fans are high with needle@ 0 and ac disabled. Cat code says failed cat. Don't remember #. Exhaust is modified with the O2 wires extended. Due to header and aftermarket cat.
Forgot to add that if the battery is disconnected for about 5 minutes, when reconnected everything works fine for anywhere from a hour to a day or so.
expected since disconnecting the battery erases the codes so the pcm no longer sees any problem. once the test fails again & the cooling code resets, it's back to square one with the symptom set.
Pulled battery to reset computer. My wife drove for 30 minutes before the gauge dropped, an hour after temp gauge went to 0 the check engine light came on. That code should be my exhaust code. When I get home I'm going to replace the pigtail. I don't know what's up. This sucks
I have experienced multiple thermostat failures due to the internal rubber seal. It shifts and has locked the thermostat closed, causing my engine to overheat, and just again stuck open by twisted seal causing full temperature to NOT be reached. Which disallows AC usage and shows no reading on internal temperature guage. New thermostat is the same design.
The name on it is Motorad. Last night I stopped at OReilly, Autozone, and Bumper 2 bumper to look at the thermostats. Gates, Murray, and Duralast all are the same design. Only the AC DELCO has a different design. I'm going to get it and put it in when I can get back to working on the car. I don't have any faith in the other designs. No one here has a Stant one, can anyone post a picture of that? Has anyone seen another brand that is like the AC DELCO style?
I have a 2006 G6 GTP that today the temp gauge went out and then the AC wouldn't blow cold air... after looking on here and what everyone was posting, I changed the coolant temp sensor and it didn't work... then I looked on here again and someone said to check the Battery terminals to see if there was corrosion that the BCM wasn't getting enough volts to work properly. I cleaned the terminals that needed it badly and it worked. thank you to everyone that has posted knowledgeable info on here!!!
I have a 2006 G6 GTP that today the temp gauge went out and then the AC wouldn't blow cold air... after looking on here and what everyone was posting, I changed the coolant temp sensor and it didn't work... then I looked on here again and someone said to check the Battery terminals to see if there was corrosion that the BCM wasn't getting enough volts to work properly. I cleaned the terminals that needed it badly and it worked. thank you to everyone that has posted knowledgeable info on here!!!
I had the same issue. Did tons of research, took it to several shops with several different guesses and finally to GM. They told me it was the thermostat which I disagreed because it was mechanical and nothing from the thermostat is connected to the temp gauge. I could also make it work for a day or two by disconnecting the battery. Again, disconnecting the battery would have nothing to do with the thermostat so I was convinced that was not it. They explained it to me and it made perfect sense. If the thermostat is not working, the car will run too cold or too hot, too cold in my case. The computer is set for he car to run within a certain temperature range. If it does not, it will send a fault message, usually P0128 to the computer which will shut down the air conditions, set the temp gauge to C and make the fans run all the time. I had them change the thermostat and it fixed all the problems.
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