[Randalledelphia]

Hello all, my 2014 will be at normal operating temperature and occasionally the temperature gauge will drop to the bottom of the scale and the fans turn on, and then the AC will stop blowing cold air. If I shut it off for 30 seconds or so. It will then go back to normal once I restart it. Then it’ll happen again a short time later. The codes that are being set are P0118 and P0119. My guess is the ECT sensor is the culprit but maybe it’s something else? One other thing I have noticed is the lower radiator hose at the thermostat housing will be cool to the touch when the fans are running like the thermostat is stuck closed not allowing the coolant to circulate. I changed the thermostat, but that did not solve the problem.

 

[Collibt]

Did you find out what the issue was? My wife’s is doing the exact same thing.

 

[sjames]

Any Luck?

Oddly enough, my wife's 2014 Acadia started doing this exact thing this week. Went left the house and within a block the a/c died. Came back home, shut off the engine and the fans were on full blast after the engine shut down. We gave it a few seconds, started it back up, and everything worked.

A few days later she called me and said her a/c died again and that her temp gauge was at the bottom (this was after about 30 mins of driving). When she got home, I put in a new thermostat. Drove it around for about 10 mins and the car stayed at 210 on the gauge (as it should) and the a/c worked fine. This lasted for 2 days and then it went back to dropping the water temp, killing the a/c.

My thoughts are of course electrical. The temp gauge can't fluctuate that drastically without it being some sort of circuit/relay/sensor issue. I think something is throwing a bad voltage, confusing the car and it is dropping the a/c; just like it does when the car gets too hot, except this isn't a 'too hot' issue.

Let me know if anyone has found out anything, I plan to call the dealership today. We purchased this new in 2014.

-Steven

 

[Clock97]

Any updates on this issue? We are having the same problem

 

[Rbank]

My 2014 Acadia has the same problem. I am going to change the coolant temp sensor out this morning and will let you know if this fixes the problem.

 

[Rbank]

Yes, my 2014 Acadia was doing the same thing, when temp gauge would drop the a/c would quit.
after ready a couple online post on how the system operates, this is what I see. when the temp gauge drops the controller does not know what temp the engine is so it goes into protective mode. It turns the a/c off in case the outside temp is below freezing to protect the compressor from damage. It also turns on both cooling fans in case the engine is overheating. This is why the fan turns on and may run after the car is turned off. With the temp sender being the possible cause I decided to replace it. The sender is located on the front side off the front head between the #2 and #4 cylinders, under a silver protective cover. When changing the sender out I did not want to have to drain the coolant, so in removed the filter and dumped the dirt out of my shop vac. and placed the hose over the radiator fill neck on radiator and held a vacume while i replaced the sender. this did suc about 1/2 gal of coolant out which I topped off with new coolant. I took the car for a test drive and the temp gauge worked like it was supose to and the a/c cool again!!!

 

[Acadia77000]

Anybody figure it out

My 2014 GMC Acadia Just started do the same exact thing!! Temp gauge drops to straight down, Fan blowing full and loud, A/C still Blows but Not cold and the recirculation button flashes. Kind of odd that it is the 2014's that have started doing this. Another way for GMC to make up spend money.

Hope someone figures it out and it is an easy fix. Please Share if you do!!

 

[BillyMck]

My wifes 2019 Acadia just did this today. Going to check the sender and see if thats the fix on this model as well

 

[dcampa]

Yes, my 2014 Acadia was doing the same thing, when temp gauge would drop the a/c would quit.
after ready a couple online post on how the system operates, this is what I see. when the temp gauge drops the controller does not know what temp the engine is so it goes into protective mode. It turns the a/c off in case the outside temp is below freezing to protect the compressor from damage. It also turns on both cooling fans in case the engine is overheating. This is why the fan turns on and may run after the car is turned off. With the temp sender being the possible cause I decided to replace it. The sender is located on the front side off the front head between the #2 and #4 cylinders, under a silver protective cover. When changing the sender out I did not want to have to drain the coolant, so in removed the filter and dumped the dirt out of my shop vac. and placed the hose over the radiator fill neck on radiator and held a vacume while i replaced the sender. this did suc about 1/2 gal of coolant out which I topped off with new coolant. I took the car for a test drive and the temp gauge worked like it was supose to and the a/c cool again!!!

Is the temperature sender the same thing as the temperature sensor?

 

[speleos]

Is the temperature sender the same thing as the temperature sensor?

Seems to be an ECT problem. I believe this is what is discussed in the member's reply:

Remember, 2014 Acadia and Traverse use the same engine type.

 

[Ilimaz_1]

Seems to be an ECT problem. I believe this is what is discussed in the member's reply:

Remember, 2014 Acadia and Traverse use the same engine type.

Hi, did this fix the problem? Mine doing the same thing.

 

[IAmBazookaJoe]

I had the same problem. Temp gauge stops working and A/C stops too. With a little searching on google and right here found the Coolant Sensor to be the solution. I think it was a $30 part from Oriley's. It took less than an hour to change only because I took the plastic cover off to check the radiator level and to get the wire harness out of the way. I like a clear path when working on my car. Bungee to hold the wire harness out of the way (not under much tension!)

A 19mm deep well fit right over

Remember there is a plastic tab that must be removed or pulled back to actually unplug the sensor (I broke it 😩) hope it doesn't wiggle loose. I did apply a small amount of dielectric grease to the plug, which i usually do with electric connections.

View from the top. The silver boot is covering the sensor right next to the oil dipstick

I hope this helps anyone who runs into the same problem. Super easy fix.

 

[R Dean Roden]

Crazy. My 2017 Acadia started doing it last week while on vacation in Florida. Did it on our way back. Drove from Ft Walton Beach to like 5 miles to Kentucky and needle dropped all the way down. Pulled over at the Kentucky welcome center rest stop to shut the car off. Popped the hood, everything was cool to the touch after like 9 hours of driving. Went to restart it and the engine was revving up like my foot was on the gas. Turned it off again. Waited 5 min. Wouldn’t start or turn over, waited 5 more, same thing. Waited about 10-15 minutes then it started.
How does an ongoing issue from 2014 - 2019 continue to happen!?

 

[genesmachines]

Crazy. My 2017 Acadia started doing it last week while on vacation in Florida. Did it on our way back. Drove from Ft Walton Beach to like 5 miles to Kentucky and needle dropped all the way down. Pulled over at the Kentucky welcome center rest stop to shut the car off. Popped the hood, everything was cool to the touch after like 9 hours of driving. Went to restart it and the engine was revving up like my foot was on the gas. Turned it off again. Waited 5 min. Wouldn’t start or turn over, waited 5 more, same thing. Waited about 10-15 minutes then it started.
How does an ongoing issue from 2014 - 2019 continue to happen!?

So, it looks like you guys have nailed it on the 2014 Acadias ---- Engine Coolant Sensor needs replacing. I am helping a neighbor with a 2017 that appears to have the same issues ---- dash temp gauge reading cold, radiator fan running continuously from start-up and air conditioning running warm. Also have a warning on the dash saying "Steering Assist is Reduced" and a P0128 check engine code that says "Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temp). I suspect this is still part of the same issue, because they all showed up at the same time. GMC must've made a major engine change around 2016-17 because the engine compartment looks completely different than what I'm seeing on your enclosed videos. And I can't seem to find any videos or chats on the 2017s. So, my main question is "Where is the engine coolant sensor located on these newer engines?" I hope no one else is having this problem on their 2017 through 2019, but I hope someone knows where to start looking for this sensor. I don't really care to go ripping off all kinds of engine covers just to find it.
Thanks,
Gene

 

[speleos]

... So, my main question is "Where is the engine coolant sensor located on these newer engines?" ...

According to this diagram from GMPartsDirect, the coolant temperature sensor (# 6) is located at the lower left (driver's) side of the radiator: Coolant Temp Sensor - GM (12650595)

 

[speleos]

... GMC must've made a major engine change around 2016-17 because the engine compartment looks completely different than what I'm seeing on your enclosed videos. ...

They have changed 3.6L engine variant from the LLT to the LGX. You'll find many differences between the two of them.

 

[genesmachines]

According to this diagram from GMPartsDirect, the coolant temperature sensor (# 6) is located at the lower left (driver's) side of the radiator: Coolant Temp Sensor - GM (12650595)

Thanks speleos, I'll be getting under the hood today
Gene

 

[paris289]

I actually have a 2017 Acadia Denali and mine started doing this exact same thing about 6 months ago, but a couple days later, everything went back to normal. I read on this forum that the Coolant Temp Sensor was the main problem on the older models, so I went to the GMC dealer and purchased a new sensor. I figured I would wait until it problems happen again, and then change the sensor. However, the Acadia ran great all summer, until last week, the temp gauge dropped to 0, the air blew warm, the rad fan was racing, and the "Steering Assist is Reduced " warning came on the dash. I drove the car the next day and in the middle of my drive, everything started working again. Then last weekend, I finally had time to replace the Coolant Temp Sensor. It is not in the same place as everyone says for the older models. It took me 3 hours to find it, but I finally did and replaced it. It is actually on the top of the engine, left side under the air intake cover. I thought everything would be fine, but then today, all my problems came back. Now I'm puzzled, what is wrong with these that this problem keeps coming back? Do you think its the thermostat?

 

[paris289]

If you wanted to know where the Sensor is on the 2017, its #54 in this diagram.

 

[genesmachines]

I actually have a 2017 Acadia Denali and mine started doing this exact same thing about 6 months ago, but a couple days later, everything went back to normal. I read on this forum that the Coolant Temp Sensor was the main problem on the older models, so I went to the GMC dealer and purchased a new sensor. I figured I would wait until it problems happen again, and then change the sensor. However, the Acadia ran great all summer, until last week, the temp gauge dropped to 0, the air blew warm, the rad fan was racing, and the "Steering Assist is Reduced " warning came on the dash. I drove the car the next day and in the middle of my drive, everything started working again. Then last weekend, I finally had time to replace the Coolant Temp Sensor. It is not in the same place as everyone says for the older models. It took me 3 hours to find it, but I finally did and replaced it. It is actually on the top of the engine, left side under the air intake cover. I thought everything would be fine, but then today, all my problems came back. Now I'm puzzled, what is wrong with these that this problem keeps coming back? Do you think its the thermostat?

You're right Paris289, the coolant sensor wasn't on the radiator. The parts breakdown that speleos send me was for a Denali and I was working on an SLT (sensor on top of the engine like you say). Thanks in any case speleos, it got me looking and thinking in the right direction. So, finally changed it out after pulling the intake manifold to get a better shot at it. Still had to use makeshift tools ---- I could get a socket on it but not an extension straight in ----- probably some kind of a special extension would have done it, but it wasn't in my toolbox. Got the job done, started the engine and still the same problems. I couldn't clear the trouble codes (P0118 Engine Coolant Temp Circuit High and P0128 Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temp)). I have two different code readers (one is a TOAD software on my laptop) neither one would clear the codes. So, I finally gave up and gave the vehicle back to the neighbor lady and told her to take it to a shop. She texted me the next morning that on her drive into town, everything went back to normal. When I got my code reader on it, all the codes had cleared. Magic? Now when I hear what you have to say Paris289, I wonder if it's really fixed. Still leery about the thermostat code, but I can't even see where that is ---- someplace low on the engine where it would be a bear to try to get at.
If anyone has some more input or experience with these vehicles, I'd be interested to hear your story. How long have temp sensors been on vehicles? 1920s, 1930s, the 40s for sure. And they very seldom failed. You would think that they would have figured out how to make them last more than 4 or 5 years by now. OK, I'm done with my rant. Someone else's turn!