coolant temperature sensor location for replacement?

The cooling fan is controlled by the cylinder head temp sensor through the PCM, the PCM monitors the temp and turns on the low and high speed fans as required, i would first be looking at a stuck open relay, there are 3 relays in the battery junction box, left rear of the engine bay. Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

When the heat is on and I am idling, it acts as it is going to stall out. It does it three times in a row. Also, in the cold winter, as soon as I start the vehicle up the cooling fans turn on immediately and run the entire time. My temperature gauge does not read hot, in fact I am not sure it actually gets up to temperature, because the gauge sits just below half. Recently my engine light came on with an EVAP leak. I am thinking this is a temperature sensor?

I think you have a couple issues going on here. I think you are correct that the temperature sensor could be the reason the fans stay on. You have a cylinder head temp sensor shown in the attachment.

As for the EVAP code, what was the actual code?

Then the stalling could be related to the EVAP code so let's start with that but I attached a guide that runs through the stalling at idle. Give that a read and let me know what questions you have.

https://www.2carpros.com/articles/stall-at-idle

Kenny, thank you for replying. I did order a coolant temperature sensor, but it doesn't look anything like the cylinder temperature sensor. I did attach a photo of what I have. Which one should I replace? Honestly I hadn't been able to locate were the one I do have goes. I will read through the article as well and let you know my thoughts. I am not trying to be frugal, I just like to figure things out o n my own. Haha. As for the EVAP code, I was able to clear it so I will have to wait until it Pops on again. I know that it said very small leak, if that helps!?! Thank you so much for your help!!!

Okay. You said you have a 4 cylinder so is that the 2.5L? This is a common confusion. I have run into numerous people on this site that get a temperature sensor that they can't find and the CHT sensor is not the part that they ordered. Take a look at the attachment.

Also, the picture did not attach if you don't mind trying that again. Thanks

Yes, it is a 4 cylinder, 2.5 liter. I apologize the picture didn't attach. I tried again.

Okay. Is that the new sensor or the old one? I show the same type of sensor for replacement that I looked up on a parts website.

I also attached all the sensors on the engine. As you will see there is a cylinder head temp sensor and that is it.

Have you tried to install the sensor in the engine? Does it thread into the head and does the plug connect to it?

The physical appearance may be different but as long as it goes in and connects then you should be fine. If it doesn't fit then these are clearly not correct and we are having the same issue others have had.

At that point, provide me your VIN and I will reach out to one of my Ford dealers and have them get a part number for this sensor.

Hi Kenny, actually today I figured out from my Chilton book, that the part in my picture was for a V8. I did get the correct on and was successful at changing it. At first I thought it had fixed the problem, !u fans weren't running on start up!!!

I celebrated too soon. I started it later on in the day after it if fully cooled and the fans started going right after I started the vehicle. I did check the whip to make sure it is getting power, I also checked the relays and fuses and for any obvious cracks in hoses. I just don't know where to go from here...

Sorry V6 not V8, haha.

Okay. Are both fans coming on when starting during a cold start? If they are then the PCM is commanding them on and we need to monitor the PCM to see what the inputs are telling it to determine if the PCM is turning them on because of a sensor issue or it is the PCM itself.

Is there any chance you have a scan tool that can monitor the PCM data?

Unfortunately, without this we would be guessing because if you look at the wiring diagram the PCM controls the power to the fans. The wiring diagram also only shows the CHT sensor as the input to the fans but this is misleading because if the AC is on it turns both fans on as well.

Both fans are coming on. Now it is happening sometimes, instead of all the time. I do not have a scan tool to monitor the PCM unfortunately, but I would be glad to get one. is there one that you recommend? I only have a code reader right now. I did plug that in today to see if any codes were detectable, and it did come up with the code "P0456".

Okay. That is not related. I would hate for you to buy a scan tool just for this. However, if you are going to use it then I have found that most of the more basic tools that just read codes and live data are pretty good. Most of them are around $100 and google displays the most popular when you search for scan tools. I have seen a lot of DIY people use the Innova 5210 but clearly there are a lot of options.

The fact that you don't have codes and both fans are on high, I suspect the AC pressure is high causing the PCM to think it needs to have them on to try and lower the pressure so it cools better.

Take a look at the attachment. What is your voltage when you put your meter on the 5 volt supply and ground? Then what is the voltage when you put them on signal and ground? Clearly you do this when the engine is running and fans are on. Also, when the fans are on and the AC is on, does the compressor cycle? You don't need a scan tool to do any of this so only buy one if you want to at this point. If we get to the point when we need one, I will tell you. Thanks

Hey Kenny, sorry I have been busy due to the Corona virus (I'm a nurse). I went and got a reader... the only thing I could find related to PCM was the voltage, picture attached...

Good afternoon,

I thought I would throw my 2 cents in on this.

first, if the coolant temperature is not coming up to temp, I would replace the thermostat. If it is running cooler, the engine will run rich as the fuel mapping will still see cold engine.

Second, do you have automatic climate control? If you do, then the fans will come on as the A/C system will be working.

Roy

Hi Roy,

Thanks for your input! I hooked up my reader and the temp gets up to 95 Celsius and I do not have automatic climate control. The fans come on no matter if the A/C is running or not. And it happens intermittently. Some days when I turn the vehicle on the fans will come on right away and some days it wont. But it seems like once they are on, they are running constantly without shutting off.

Okay, thanks.

I had one like this a while ago and I found out the PCM was the issue commanding the fans on when they are not needed.

I replaced the PCM, had it programmed and that fixed it.

Just one real experience I had a few years back.

Roy