# Engine Cooling Fan Constantly Running???



## Avnwarrior (Mar 13, 2014)

Every single time I have started my car today, the cooling fan has kicked on immediately. Even when the gauge reads 3 little tick marks above cold. Any ideas? It's never done that to me before. 2011 Cruze 1LT 50,477mi


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## Aussie (Sep 16, 2012)

Is the a/c on or in defrost mode?


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## titan2782 (Nov 4, 2011)

What year/model? My 2011 Eco had the same issue and they resolved it with an ECM update. Seems dumb though since it happened around 40k miles. It would turn on full blast when I turned the car on, and stay on unless I turned the car off and restarted it, then it went back to normal. This was the same time I had the weird idle issue, too. Is your cruze having any other issues?


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## Avnwarrior (Mar 13, 2014)

A/C is not on and yes I have a small coolant leak from the overflow hose connection at the water outlet. I put more coolant in it at lunch. It won't ever kick the fan off though, no matter how cool the engine is


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## Robby (Mar 1, 2013)

There is a reflash for this.

Rob


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## Chevy Customer Care (Oct 29, 2011)

Avnwarrior said:


> Every single time I have started my car today, the cooling fan has kicked on immediately. Even when the gauge reads 3 little tick marks above cold. Any ideas? It's never done that to me before. 2011 Cruze 1LT 50,477mi


We definitely recognize these concerns involving the cooling fan running, and I would be happy to look into this further and contact the dealership on your behalf. Feel free to send me a private message! 

Patsy G
Chevrolet Customer Care


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## usspapaw (Dec 11, 2014)

Having the same problem.
I have a 2012 cruze, fan runs all the time and it is loud..
I have 40,000 miles,.
Does anyone know if this will be covered or what it is that is
causing it..

Thanks, papaw


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## AutumnCruzeRS (Sep 10, 2012)

To add to this I recently added some driving lights running the power source straight from the battery. Im not sure what its called but it didnt like the negative ground wire directly to the battery. Has to be thru the loop all the other negative cables go thru. My fan ran constantly on high while the - wire was directly wired to battery.


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## Robby (Mar 1, 2013)

usspapaw said:


> Having the same problem.
> I have a 2012 cruze, fan runs all the time and it is loud..
> I have 40,000 miles,.
> Does anyone know if this will be covered or what it is that is
> ...


The dealer will have to diagnose for the cause of your specific problem.....may or may not be powertrain related.
Currently I'm leaning towards not but you may be pleasantly surprised.

Rob


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## ChevyGuy (Dec 13, 2014)

AutumnCruzeRS said:


> To add to this I recently added some driving lights running the power source straight from the battery. Im not sure what its called but it didnt like the negative ground wire directly to the battery. Has to be thru the loop all the other negative cables go thru. My fan ran constantly on high while the - wire was directly wired to battery.


The "loop" is a current sensor. It's supposed to sense how much charging current the battery is getting. If you bypass that loop, the car gets very confused about how much current is going into the battery. 

I thought I saw a guide from Chevy about installing 2-way radios into the car. Of course, now that I'm looking for it, I can't find it. But from what I remember, it said to NOT connect directly to the battery, but to the ground point where the battery connects.


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## pL2014 (Dec 29, 2013)

When I installed my upgraded headlight wiring, I had the same problem. Disconnecting the battery for a few minutes and making sure the new harness was grounded via a ground point fixed the fan issue. No problems since.


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## cruze999 (Feb 2, 2013)

Is that ECM update a PI?


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## Iraitt (Jul 24, 2015)

I am having a similar problem with my 2011 Cruze. When I run the a/c the fan comes on at high speed every ten seconds or so. I talked to a few mechanics and they said it was normal, I don't buy this since it only started doing this recently. I called my local GM dealer and spoke to someone in service and he had no idea what I was talking about.

No longer sure what to do about this problem, I'm not using my a/c for the time being but would like to resolve the issue.


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## jblackburn (Apr 14, 2012)

Iraitt said:


> I am having a similar problem with my 2011 Cruze. When I run the a/c the fan comes on at high speed every ten seconds or so. I talked to a few mechanics and they said it was normal, I don't buy this since it only started doing this recently. I called my local GM dealer and spoke to someone in service and he had no idea what I was talking about.
> 
> No longer sure what to do about this problem, I'm not using my a/c for the time being but would like to resolve the issue.


If it's running off-high-off, the fan needs to be replaced. The low and medium-speed relay has gone bad, and I think it's all integrated into the whole thing on a Cruze. High speed bypasses the relay and gives full voltage as commanded by the ECU.


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## Aussie (Sep 16, 2012)

My Cruze has 2 fans on the radiator, is this normal for all Cruzes, or only on the diesel? I thought the a/c fan only may be faulty?


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## jblackburn (Apr 14, 2012)

Aussie said:


> My Cruze has 2 fans on the radiator, is this normal for all Cruzes, or only on the diesel? I thought the a/c fan only may be faulty?


Only one fan on US gas models. Don't know about the diesel.


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## ChevyGuy (Dec 13, 2014)

jblackburn said:


> If it's running off-high-off, the fan needs to be replaced. The low and medium-speed relay has gone bad, and I think it's all integrated into the whole thing on a Cruze. High speed bypasses the relay and gives full voltage as commanded by the ECU.


It's the resistor, not the relay. But same deal - you have to replace the fan as it's not sold separately.


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## Iraitt (Jul 24, 2015)

So is it the rad fan motor that needs to be replaced or the rad fan module?



jblackburn said:


> If it's running off-high-off, the fan needs to be replaced. The low and medium-speed relay has gone bad, and I think it's all integrated into the whole thing on a Cruze. High speed bypasses the relay and gives full voltage as commanded by the ECU.


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## jblackburn (Apr 14, 2012)

Iraitt said:


> So is it the rad fan motor that needs to be replaced or the rad fan module?


The whole thing is sold as one assembly


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## Rivergoer (Mar 30, 2017)

jblackburn said:


> Only one fan on US gas models. Don't know about the diesel.


Just checked my Gen 1 CTD, only one fan on the US diesel as well.


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## NickD (Dec 10, 2011)

Cooling fan is misleading, all fans cool, either the radiator fan or the MVAC blower motor fan.

If we are talking about the radiator fan, a brush type permanent magnet armature, one of three wires feed it, direct, small resistor, large resistor that each is connected to a point contact relay giving three speed, high, medium, and low.

These relays are mounted in the underhood fuse relay box, if you pull the cover and flip it over, shows the location of each one. if you pull all three, the fan will not work at all, possible one of the three has a sticking contact or weak or broken return spring, or even dirty contact. That will produce erratic operation. And are plug in type relays for easy replacement.

Voltage for the solenoids of these relays comes from yet another contact from the ignition relay, also identified. ECM controls the ground side of each relay solenoid. If the relays are good, possible ECM problems, really not that hard to diagnose if you know what you are doing.

Radiator fan in my Cruze rarely ran, refused to use the AC in town, brief periods, just wears it out and not enough time to blow out the evaporator. On the highway with that large radiator and a good 55-70 wind, sufficient enough for radiator cooling with the fans. Also keeping your condenser clean reduces bug restriction, yes we have bugs up here. 

Voltage for those three relays contacts is always hot, so the fan will run with the ignition off if a relay contact is welded shut, you will wake up to a dead battery.


Blower motor is all electronic, controlled by the BCM, this gets a bit more complicated.


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## Aussie (Sep 16, 2012)

jblackburn said:


> Only one fan on US gas models. Don't know about the diesel.


Hard to photograph, but this is what the 2 fan setup looks like.

View attachment 235314


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## ChevyGuy (Dec 13, 2014)

Aussie said:


> Hard to photograph, but this is what the 2 fan setup looks like.
> 
> View attachment 235314


Given the way the ECM outputs the fan signal, that makes sense. I'll bet one fan is "low", the other is "medium", both are "high". Because that's the way the ECM outputs the fan signal. Just two relays to run two fans. 

On the US Cruze, they have a collection of 5 relays to convert that signal to a drive a larger 3-speed fan.


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## Aussie (Sep 16, 2012)

Not sure on the Cruze, but on my previous Commodore, one fan ran when the a/c was on and both turned on when the set temperature was reached, even if the a/c was off.


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## jblackburn (Apr 14, 2012)

Aussie said:


> Not sure on the Cruze, but on my previous Commodore, one fan ran when the a/c was on and both turned on when the set temperature was reached, even if the a/c was off.


My Saab 900 was the same setup.


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## ashleyautumn (Feb 21, 2018)

Avnwarrior said:


> Every single time I have started my car today, the cooling fan has kicked on immediately. Even when the gauge reads 3 little tick marks above cold. Any ideas? It's never done that to me before. 2011 Cruze 1LT 50,477mi


Did you ever get this figured out? If so, how much was the repair? The exact same problem started occurring with me yesterday... I am not sure how costly this is going to be...


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## Asavedra (Oct 30, 2018)

What is a reflash? My car is having this same issue, and the fan stays on until it drains my battery


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## Tigrig (May 29, 2018)

My fan just started running high speed today and won't kick down. No CEL. What is the issue? Any idea


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## Aussie (Sep 16, 2012)

Tigrig said:


> My fan just started running high speed today and won't kick down. No CEL. What is the issue? Any idea


 That happens on my 2012 Cruze diesel if the engine is doing a regen when I turn it off, but it turns off after a couple of minutes. As there are 2 fans it really roars for that couple of minutes.


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## Tigrig (May 29, 2018)

Mine isn't a diesel. It's a 1.4t. The temp gauge is reading normal a/c is off. Could the thermostat be getting stuck open intermittently and not showing a change on the guage?


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## ChevyGuy (Dec 13, 2014)

Tigrig said:


> My fan just started running high speed today and won't kick down. No CEL. What is the issue? Any idea


What do you mean by "won't kick down"? The Cruze is supposed to have a 3-speed fan, but when the resistor pack dies, it transforms from low-medium-high to off-off-high. The resistor pack is not sold separately, so the fix is to replace fan assembly. 

If it's going to high and staying on high, then it's something else. Possibly an A/C problem.


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## Tigrig (May 29, 2018)

I went or today and started my car. Utter now says a/c off due to high engine temp. The engine didn't even have time to get warm. The fan is still running after shutting it off. I think it might be one of the temp sensors.....any feedback. How can I tell which sensor if so?


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## ChevyGuy (Dec 13, 2014)

See if you can scan it for codes.


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## njesse124 (Jun 17, 2019)

*Chevy Cruze Fan Issue*

This issue is pretty common with the fan on most models in this year range, I'd first check the relays to make sure they are clicking and working properly, then if they are check the connector going from the fuse box to the fan (It should be a huge plug that's plugged into the fan, you'll know it when you see it). The cooling fan runs on a HIGH, MID, LOW circuit, and when one circuit doesn't work properly, it automatically reverts to the highest voltage circuit (HIGH), thinking that the car is over heating (Even if its not) to refrain from high temp damage. If there are burn marks or corrosion on the massive plug in the fan then that is most likely your issue, if not then I'd take it to a dealer or get a diagnostic tool (There could be issues with the ECM) Other wise, a new plug would be the best bet. Also, here's a video going over all of this in this paragraph, Hope I could help, good luck! 

VIDEO ONE: https://www.youtube.com/watch?v=xHZVvHIbs9s&list=LLknoh9vzFyaqgWxm0yaUJfg&index=3&t=0s
VIDEO TWO: https://www.youtube.com/watch?v=vezjDh2I2kc&list=LLknoh9vzFyaqgWxm0yaUJfg&index=2&t=0s


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## njesse124 (Jun 17, 2019)

TigRig, Check thermostat?


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## bobby dewey (Oct 20, 2018)

Avnwarrior said:


> Every single time I have started my car today, the cooling fan has kicked on immediately. Even when the gauge reads 3 little tick marks above cold. Any ideas? It's never done that to me before. 2011 Cruze 1LT 50,477mi


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## bobby dewey (Oct 20, 2018)

Check thermostat it was mine that cause the fan to run


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## Ardneat (Apr 30, 2020)

I am having the same issue with the fan, it turns on and runs high just a few minutes after starting car in the morning - no a/c or defrost on. Just had thermostat changed out two months ago, I changed out the coolant temp sensor that sits just under the coolant overflow. I have no coolant leaks and a pressure test on the coolant system has been done. I have had nearly the entire coolant system changed out in this thing over the past few months. I expect better from GM than to be having these issues, even with a 2011. I keep my vehicle maintained and do not drive my card overly hard by racing and revving it. Poor engineering, making everything from a material that turns brittle over time and use so it ends up nickel and dime-ing a person. I have always been a dedicated GM consumer, it may be time to do some research and give another manufacturer a go. This is too frustrating.


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## sheilatinch (Jun 4, 2021)

so have anyone found the answer to the problem


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## Blasirl (Mar 31, 2015)

sheilatinch said:


> so have anyone found the answer to the problem


Could be air in the system or maybe the second temp sensor is bad.

Burp the tank video

coolant bleeder

Loud Fan Noise


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## Kellt (Jul 28, 2021)

I just had this issue with my daughter's 2012 CHevy Cruze LT 1.4 Turbo. After completing an oil change and the boost pressure sensor coming completely off the intercoolant hose, we now had a check engine light on the car was blowing P0132, P0134, P0135, P0236, and P0237 codes and the fan was running on high speed as soon as we started the car. We took the advice of many people on this site as well multiple videos, we changed the MAF sensor, Coolant Temp sensor, swapped out the thermostat, and checked all relays as well as the coolant fan. None of these things worked, finally gave up and brought it to Chevy dealer and turns out the O2 sensor was completely fried ( per the mechanic working on it is was burnt) and the PCM was also fried.


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