# P00B4 code and radiator fan running constantly on max



## Johnny B (Jun 4, 2019)

trevor267 said:


> replaced both coolant temp sensors


What were the part numbers and the vendor?


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## trevor267 (11 mo ago)

ACdelco Part # 213-4688


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## Johnny B (Jun 4, 2019)

Install this sensor in the "coolant outlet". And don't forget me on the Christmas card list.



More Information for ACDELCO 55591401


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## trevor267 (11 mo ago)

Thank you I will certainly try that. Now when you say coolant outlet you are talking about the one on the radiator right? And not the one on right side of the engine


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## Blasirl (Mar 31, 2015)

trevor267 said:


> Thank you I will certainly try that. Now when you say coolant outlet you are talking about the one on the radiator right? And not the one on right side of the engine


The water outlet is the one on the block.

Also make sure you have evacuated ALL of the air in the system


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## Johnny B (Jun 4, 2019)

trevor267 said:


> you are talking about the one on the radiator right?


NO, I am not. As Blasirl stated the coolant outlet is on the block. That is why I put coolant outlet in quotes, replace the "coolant outlet" sensor.


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## trevor267 (11 mo ago)

Alright sorry I'm not familiar with this car at all. I will replace the outlet with that part number. So does the one on the radiator take the part number that I provided? The guys at the parts store told me they were both the same but I sure wouldn't be surprised at them being wrong. Really appreciate the help guys


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## trevor267 (11 mo ago)

Local parts store says they will have ACDELCO 55591401 tomorrow by 4pm. Will come back and post results. Thanks again, but could you still clear up for me what part number coolant temp sensor should be on the radiator side?

Thanks


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## Johnny B (Jun 4, 2019)

trevor267 said:


> The guys at the parts store told me they were both the same


Make your choice, me or the geniuses at the parts store.



trevor267 said:


> what part number coolant temp sensor should be on the radiator side?


The part number you said was installed in the radiator is the correct one.

Listen dude, I'll give you a big freaking bone here. People come on this site constantly with the same problem because some parts guy told them same same BS you are being told.


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## trevor267 (11 mo ago)

just here with questions man never said anyone was right or wrong still appreciate the answers


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## Johnny B (Jun 4, 2019)

After this is all over, you should print this thread out and give to your parts guy.  I can tell you right now who is right. Unlike what is ultimately important to people, a car doesn't care about opinions.

I was waffling on whether to tell you this now or later. 
After you install the correct coolant outlet sensor the system still won't work right because the code needs to be cleared. After you clear the OBD codes, then the fan will operate normally again.


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## 559cloud (Aug 20, 2021)

first must say love cruzetalk my son's 2015 cruze lt 1 day temp sensor just stayed on cold and AC was off due to high engine temp and then BAM the Fan stayed on and blew on high all the time. what worked for him was changing the thermostat its been 3 weeks and all is well.


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## trevor267 (11 mo ago)

I may have to try the thermostat. I replaced the outlet sensor with the correct one, cleared the code but the fan still turned on immediately and the code came back shortly after. Any other ides?


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## trevor267 (11 mo ago)

Although I don't really think it is the thermostat because I can turn the a/c on it doesn't get cold because of a leak in the condenser but I'm still able to turn it on and blow hot air. Car never overheats and usually hangs around 190 due to the fan always being on


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## 559cloud (Aug 20, 2021)

Hello my sons car never overheated its a common thing i think AC of due to High Temp will show up on dash you can search it here. I have read on here that sometimes the pins go bad on the fan only allowing one speed to work wich is usally high.you can get lost looking at all the little things that can throw off the system with pvc leaks.All i know for my son in order to get the fan from blowing high all the time was the thermostat.


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## 2016CRUZ937 (Feb 23, 2021)

Johnny B said:


> Make your choice, me or the geniuses at the parts store.
> 
> 
> The part number you said was installed in the radiator is the correct one.
> ...


I had the same issue with my radiator fan always running even in 20° weather!! I just put in a new thermostat {replaced junk plastic thermostat with the upgraded aluminum one} now it works fine I tried to sensors and all that all I was doing was wasting money. Hope that helps! Good luck...


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## trevor267 (11 mo ago)

Alright I'll have to look into a thermostat then. Appreciate all the answers. Good community here


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## Ozzy1584 (10 mo ago)

So after replacing the 2 temp sensors mentioned here, and still getting the code I guess the thermostat is the next move?


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## 559cloud (Aug 20, 2021)

all i can say yhea i wish it was the two sensors but it took chaining the thermostat to stop the fan from running like a jet was coming down the street.


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## Ozzy1584 (10 mo ago)

Ok, thank you for the response I will try it. Don't know of a fan running issue in mine,but I know it does from time to time. Where is everyone getting the better aluminum thermostat, and housing?


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