ECT over OBD?

Nitori

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I’m fairly certain all analog ECT gauges have heavily damped middle ranges to the point where you basically get 3 readings from them: “cold”, “anywhere between 160 and 225”, and “lol warped deck”

I mean, this has been happening since before OBDII was even used. Many cars are notorious for not reporting accurate ECTs with their analog gauges.

People would constantly be asking why their ECTs were moving around so much if it was an actual readout. It ramps out the initial drop in ECT when the thermostat opens, and sitting in traffic on a hot day you would see it creep up until the fan kicks on and then drop, over and over.


Anyways, Honda decided they wanted to be special snowflakes and ECT is not polled via the OBD standard. You have to read some other value on the CAN bus I believe. Haven’t looked into it recently but that should at least get you pointed in the right direction.
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REBELXSi

REBELXSi

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I’m fairly certain all analog ECT gauges have heavily damped middle ranges to the point where you basically get 3 readings from them: “cold”, “anywhere between 160 and 225”, and “lol warped deck”

I mean, this has been happening since before OBDII was even used. Many cars are notorious for not reporting accurate ECTs with their analog gauges.

People would constantly be asking why their ECTs were moving around so much if it was an actual readout. It ramps out the initial drop in ECT when the thermostat opens, and sitting in traffic on a hot day you would see it creep up until the fan kicks on and then drop, over and over.


Anyways, Honda decided they wanted to be special snowflakes and ECT is not polled via the OBD standard. You have to read some other value on the CAN bus I believe. Haven’t looked into it recently but that should at least get you pointed in the right direction.
Look at that, an intelligent response lol.
 

Maroco

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What's really unbelievable here is how thick headed you're being. Show me on the gauge where the temperature is displayed and I'll paypal you my bank balance. It ain't much but it'll help, i'm sure.
I’m fairly certain all analog ECT gauges have heavily damped middle ranges to the point where you basically get 3 readings from them: “cold”, “anywhere between 160 and 225”, and “lol warped deck”

I mean, this has been happening since before OBDII was even used. Many cars are notorious for not reporting accurate ECTs with their analog gauges.

People would constantly be asking why their ECTs were moving around so much if it was an actual readout. It ramps out the initial drop in ECT when the thermostat opens, and sitting in traffic on a hot day you would see it creep up until the fan kicks on and then drop, over and over.


Anyways, Honda decided they wanted to be special snowflakes and ECT is not polled via the OBD standard. You have to read some other value on the CAN bus I believe. Haven’t looked into it recently but that should at least get you pointed in the right direction.
This is good to know, thanks!
 

FlexRex

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@REBELXSi Read it there.

I dont know about other poster alleging inaccuracies. My gauge is spot on and every notch represents a specific coolant temp in F. Maybe my wrx is more advanced in analog accuracy.

As i said, you could use something to help you find out what each notch is in terms of F degrees.

Honda Civic 10th gen ECT over OBD? B1952BDC-C2C9-4779-AAC6-0C6079518117


People would constantly be asking why their ECTs were moving around so much if it was an actual readout. It ramps out the initial drop in ECT when the thermostat opens, and sitting in traffic on a hot day you would see it creep up until the fan kicks on and then drop, over and over.
That means its working properly and reading out accurate temps. Sounds like a faulty thermostat too.
 
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REBELXSi

REBELXSi

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@REBELXSi Read it there.

As i said, you could use something to help you find out what each notch is in terms of F degrees.

B1952BDC-C2C9-4779-AAC6-0C6079518117.jpeg
I could use something like a digital gauge?
 


fabrizzio71

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I have the Blue Driver scan tool. It is about $100 bucks and connects via bluetooth. You read the info via the app on a smartphone. The live data can show almost anything if there is a sensor for it and it’s supported. It will give you engine coolant temperature.
 

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Now that we're all on the same page, lol.
I have the Blue Driver scan tool. It is about $100 bucks and connects via bluetooth. You read the info via the app on a smartphone. The live data can show almost anything if there is a sensor for it and it’s supported. It will give you engine coolant temperature.
Oooo so maybe Bluetooth connection is key! You may have cracked the code! :bow:
 

FlexRex

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I could use something like a digital gauge?
You totally could. Since its digital it adds 2whp and 5pts cool factor effect. The digital coolant gauge you already have is just for show, it doesnt really represent coolant temps.

Lucky you your speedo/rpm are digital (numbered) already.
 
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REBELXSi

REBELXSi

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You totally could. Since its digital it adds 2whp and 5pts cool factor effect. The digital coolant gauge you already have is just for show, it doesnt really represent coolant temps.

Lucky you your speedo/rpm are digital (numbered) already.
Do analog speedos have numbers or do they too just represent a useless scale?
 

Nitori

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@REBELXSi

That means its working properly and reading out accurate temps. Sounds like a faulty thermostat too.
You literally just confirmed the reason manufacturers smooth out temp readings. A drop in ECT on warmup is completely normal but service writers since at least the early 90's are sick of writing "cust states tstat is faulty" :lol:

When your engine is cold, there are 2 separate "loops" of coolant. One is in the radiator, the other is in the block. When the block "loop" gets up to temperature the thermostat slowly opens. Suddenly, coolant that is in the radiator "loop" starts rushing in, pulled by the water pump. Since the coolant that was in the radiator hasn't been inside of an engine, it is much cooler.

I'm not as familiar with WRXes as I sold my 2011 back in 2016, but that's cool if they actually report proper ECTs on their gauges. I'd have wagered that they were damped as well.

Anyways, suffice it to say that gauge damping is a thing has been such a pain in the ass for "enthusiasts" that people even go so far as to modify their gauges, the Mazda Miata being a great example:

Honda Civic 10th gen ECT over OBD? MTGLP-BothSweeps


160 to 220 being straight up and down on the needle is absurd, but again this is to keep people from bringing their cars in to dealer service departments panicking about "overheating" and "faulty thermostats"

On a similar note this is partially why hardly any manufacturer puts oil pressure gauges in cars anymore, they were sick of answering idiotic questions about it moving around all crazy-like and dropping once the car warms up because that must mean something is wrong.:crazy:
 


xcivicx

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Don't quote me but I think you need to do something to torque to get the coolant temperature. Finding what the can ? Code is or something.
 

FlexRex

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@Nitori my coolant gauge in my2018 wrx moves according to the actual ect temp. I monitored through my accessport as i did with many other temps, like oil temp. The coolant temp chases the oil temps by 15-20f.

Observing the actual accessport ect readout and comparing it at the actual analog dial made it clear that the notches represented certain temps, and the dial doesnt move until ~130f. That also means my oil is 150ish.

Its what i suggested @REBELXSi to do with his digital notched gauge. If he has ktuner or hondata he can monitor ect and see when the notches start appearing and what temp it is. His is even easier cuz its digital (mine is analog but not only cold and hot only like miatas) so he can check if its accurate and repeatable. Mine is.

As a general rule i try not to boost until the coolant needle starts moving, so 130f+ ect or 150f+ engine oil. See my coolant gauge in attached photo. Each notch is roughly 10f. Edit: The first small red notch is 130f.

Honda Civic 10th gen ECT over OBD? 1ADFD22D-4E12-4952-AEA0-131190EDA324
 
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Oddwayne

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The nicer obd2 Scanner’s can get ect temps along with many other meters. The cheap ones typically only read and clear codes
 

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You need to manually add the PID in Torque.
Go to Settings->Manage custom OBD2 PIDs and use code 0167 for Engine Coolant Temp. I also have Intake air temp configured, which is PID 0168.
Then you'll have these in the list of sensors that you configure as usual.
 

FlexRex

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@Nitori ..there may be truth to what you said about dampening. I monitored my ap and my gauge. What I said before was correct but once it settles at the 190f mark, even when ect temps got to 197 on my ap, the needle did not seem to move past 190F notch/mark. Short of overheating me car I cannot confirm if they indeed dampen the signal from say 190f on. But it does look like it has a hard time moving past 190f notch.

And also it’s the oil that chases coolant temps (from cold start) until warmed up then is surpasses the ect at 190f and reaches 200f+.
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