Arduino Coolant Sensor | Thermistor

Today I walk through how to interface a standard automotive coolant sensor with an Arduino. They are a simple thermistor in an industrial style casing and output a resistance with changing temperature. In order to read it with an arduino you must use a voltage divider and then use the steinhart equation after calculating the resistance to find temperatures at varying resistances along the sensors value curve.

Code and excel sheet linked below. If you have any questions please comment below or e-mail me below.

Stay tuned for more videos!

Tyler,
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Code and Excel Sheet Link:

[mdevidograndpacificlumbera]

Dude thank you so much for sharing what you know, it helps immeasurably, I want to build a custom instrument cluster for my 7.3 obs... You have taken all the leg work out for me. God bless

[redeye]

What size wire for wiring sensors? Building one for a cummins, exactly what I needed !

[Mtutoz]

Thanks for sharing your knowledge, i'm engineering student from Mexico and your video will help me and my team to finish a project that we have, this video must have millions of views, Thanks one more time!

[qzorn]

nice, would be a great esp32 Bluetooth project. 🧐 thanks. 🥳

[TJ.Outdoor]

you link "Intake Air Temperature Sensor Control & Pigtail Harness For GM IAT/MAT/ACT" which its not same as the one in this video, in video has closed sensor, and in the link its open. is it same or

[joshcroudace]

i know its a an old video but its precicly what im trying to achive on my truck, but if your still around i have a question about your temperature sender is it just a standard 12/24volt sensor? its all i can find in that form factor and am i safe to assume sending 5 volts to it it should work just fine as ill still be plotting just the resistance change even though the sensor is rated for 12volts?

[jetmech]

You're a legend! I was working my through my arduino code, thinking I was spot on. Had a mostly curve fit Ln() curve and everything, but I was missing the whole voltage divider concept. Thanks man.

[randorfja]

Thanks for this video. A glass of water with ice is 0C, a great reference point.

[ARA]

Your Amazon link is incorrect, It is showing an air temp sensor not coolant

[jms]

Great stuff bro. How can I add a code to control a relay that turns on/off the rad fan within certain temperature range and limits?

[stevecarlisle]

Have you ever considered interfacing all your sensors to a MCU with CANBUS output, producing PID, s compatible with TORQUE PRO.

[connorwhite]

Can’t wait to see how you integrate a display! Thanks for making these

[Car.los.Moreira]

Goddamn, dude. Thank you so much. Got me out of a tight one. I was trying to make a simple custom cluster for my bike and couldn't figure out how. Would've never thought about any Steinhart-Hart equation or average sampling... Absolutely brilliant job.
All the best to you.

[GizmodoMN]

Any chance you have the link to the coolant sensor used? The provided link is for the intake air temperature sensor.

[muzguz]

So very well done and thought out, you must be pretty proud of yourself. Thankyou & thanks for sharing.

[xvryan]

Hey mate, your little series inspired me to start my own project, but I have never worked with electronics before..
If you don't mind me asking, why didn't you got with waterproof ds18b20's?
According to my research coolant temp starts to get critical at around 115°c. Bc these sensors go up to 125° this is what I'm planning to go with.

[mehmeh]

Interesting stuff but it raises two questions by tapping the oem sensor like this, firstly is there an increase in resistance in the circuit by adding the extra cabling that can cause incorrect readings sent to the ECU and secondly what kind of voltage/overload protection measures do you have in place to contain an arduino failure so as not to fry the ECU which is extremely sensitive to voltage spikes?

[strones]

Thankf for the information, from this code how can i add other lines of code that controls an alarm whereby an alarm goes off when a certain temperature is reached.
Thanks

[jonathanmatney]

Dang Brother! Thank you for taking the time to do that! Seriously thanks! How do you get it to show Fahrenheit ? I tried playing with the code but came to nothing. Again thank you!

[dustinc]

Thanks! This works for my Auger engine gauges im building ( little Kubota diesel) got it within 1C thanks to your spreadsheet!