Toyota Yaris Forums - Ultimate Yaris Enthusiast Site
 

 


 
Go Back   Toyota Yaris Forums - Ultimate Yaris Enthusiast Site > Members Area > Off-topic / Other Cars / Everything else Discussions
  The Tire Rack

Reply
 
Thread Tools Display Modes
Old 10-16-2017, 09:11 PM   #1
CB900F2
 
Drives: 08 Sedan
Join Date: Oct 2008
Location: Toronto
Posts: 301
2017 Hyundai Elantra 2.0L - ECT operational theory

Hi All...

I own now a 2017 Elantra with their new 2.0L engine(I still own my 08 Yaris, just gave it to my son) and wanted to throw this question at your guys since I have found a lot of members on this forum are pretty knowledgeable.

My Elantra uses a ECT(Electronic Control Thermostat) which is basically a normal thermostat with a heater element integrated into the expansion wax assembly of ECT to which will allow premature opening of the thermostat by the heater heating up the expansion wax to open the thermostat.

I have been pulling live data off the PCM with my Bluedriver OBDII and I have found what I think to be very very odd coolant temperature readings..

I have posted three data readings. The one data reading that is showing the very linear rise in coolant temp and then in steady state its also linear, this is my 2006 Honda Odyssey and it has a non ECT thermostat.

The other two that you see are of the Elantra, and for the life of me, I do not see the logic in both the non linear rise in temperature to normal operating temp. The normal operating temp for the Elantra is 100DegC. and then once it finally hits approx 100DegC, the constant up and down swings in temp +- 10Deg C..

I know very little on the concept of the ECT and its part of the engine design in trying to maximize efficiency based on engine load and cooling the engine down during heavy loads and increasing the temp under normal loads but this constant swing makes no sense to me.

The graphs only show the cars speed, but I am also capturing the following data and I can post a link to a Onedrive folder if you wanna see the full data.

- Engine Load %
- Throttle Position
- Engine RPM
- Incoming air temp (throttle body)

One key data point I am not capturing is the "ECT Heater voltage the PCM is sending to the ECT" I spoke with Bluedriver and they are not able to grab this info as Hyundai uses some special codes that they can not read for this data point.

Again.. the algorithm the PCM is using to me makes no sense, and the live data readings are all from when I drive home>>work, and then back from work>>home. I take the same route every day, and drive conditions are pretty much the same except for the daily temperature outside. Even with the other data I am capturing, my laymen understanding, I do not see from the other data point why the need for this constant swing..

If anyone can make some sense of this temperature swing, please let me know.. My only concern is longevity of my car and engine...

I have asked on other Hyundai/Elantra forums if anyone who has a obdii reader that can capture live data on a 2017+ (2.0L) and post it, but no luck so far to compare.

Thanks all!!
Attached Images
File Type: jpg Elanrta_ Temp 19 DegC_.JPG (91.5 KB, 25 views)
File Type: jpg Elanrta_ Temp 24 DegC_.JPG (125.0 KB, 25 views)
File Type: jpg Odyssey _ Temp 30 DegC_.JPG (110.0 KB, 25 views)
CB900F2 is offline   Reply With Quote
Old 10-18-2017, 05:51 PM   #2
Lux
 
Lux's Avatar
 
Drives: NCP91
Join Date: Jul 2012
Location: Markham, Ontario, Canada
Posts: 114
I was a Hyundai automotive service technician until last year, so I will chime in.

A technical service bulletin is presently live (since 2016 August) for certain 2017 Hyundai Elantra models . I know, with certainty, that the the campaign affects Hyundai Elantra AD frame code. The GD frame code for Elantra GT models are not likely affected. I can't remember.

The campaign addresses erratic or unresponsive behaviour of the newly equipped electronically controlled thermostat. The ensuing symptom is excessively prolonged or delayed engine warm up, sometimes producing the diagnostic trouble code P0128. The repair is a new thermostat and housing complete assembly covered under warranty. The cost of coolant is not covered; technicians are expected to recover lost coolant from the engine during the operation and refill the cooling system with it. Common sense would oppose that... New coolant can be requested at the customer's expense.

Electronically control thermostats are employed to confer computer control over thermostat activity. By moving away from mechanical thermostats, engine emissions can be more tightly controlled by influencing combustion temperature by water temperature. Electronic control failure from the in-built thermostat heater element will regress it to mechanical control, anyway. So, there is no risk of catastrophic engine damage from runaway water temperature.

Your undulating waveform in water temperature is normal for this type of system. The engine ECU must observe changes in water temperature in accordance with cyclic duty of the thermostat heater to verify its operation. This is a self-monitoring, self-diagnosis strategy.

Comfortably speaking, until now, the ensuing overheating caused by conventional thermostat failure may not always be caught in time. So this new feature could be seen as a blessing with regards to self-preservation.
Lux is offline   Reply With Quote
Old 10-18-2017, 08:16 PM   #3
CB900F2
 
Drives: 08 Sedan
Join Date: Oct 2008
Location: Toronto
Posts: 301
Hi Lux.. Thank you very much for you feedback...

I should have noted, I have already had the TSB done to which they replaced the ECT... And the reason why they replaced it was based on feedback I sent to my dealership and the service manager forwarded my symptom to Hyundai Tech and they said its the ECT.

Here is what I told the dealership:
------------------------------------------
In regards to my 2017 Elantra, I would like to get your feedback if the coolant temperature rise from a cold start is a linear rise in temperature up to the motors normal operating temperature regardless of the outside(ambient) temperature

The reason I am asking this is that several owners including myself of the 2017 Elantra with the 2.0L have been experiencing a temperature reading based on the dashboards needle and it will bounce up and down until the coolant hits normal temp, and even then the temperature needle will sometimes still bounce up and down, and then after approx. 15-20km in driving in my case, it will then hit and stay at the normal operating temperature, the bouncing temp is generally only during the first 15km

Here is an example of what I have experienced and I posted this on a Hyundai/Elantra forum where many other owners are having this issue.

I have been watching the behavior of the funky coolant temp and I noticed there seems to be a outside temperature pattern to the coolant needle behavior. The temperature has been bouncing around +5C down to -4C in the past few weeks.. and I noticed the following...


- If the temp is +2C or >, from an overnight cold start, the coolant temp will rise linear and in about 5km or so and it will hit the normal temp setting and not change from there.

- If the temp is +1C to 0C, from an overnight cold start, the coolant temp will do its dance but only in small changes, and it will take about 8 to 10Km to get to normal operating temp and when it hits the norm operating temp, it stays there.


If the temp is -1C or <, from an overnight cold start, the coolant temp will do its dance and much bigger swings in the needle, and it will constantly take about 10 to 13km to get to its normal operating temp, and then its stays there...

Very odd.. I am thinking of getting a wireless OBDII reader (to have one also), and a app for my phone to read and log the data as I am very interested to see what is the temp the ECU is seeing during these different conditions.
Today the outside temp was -11deg C and the temp needle would not stop going up and down the scale... I would get to a stop light and the needle was at the normal operating temperature position (almost half) and then as soon as I pulled away, it would drop two points and then start to go back up and then drop down ..

I am aware that the 17 Elantra has had a recall for the electronic thermostat, but my car is not in that range.

Many other owners have been taking their car into Hyundai and they have tried several different repair action to not avail.

- They tried to change the coolant and bleed the system of air – Did not fix
- They tried to replace the thermostat even ones not in the recall – Did not fix

Here are some forum threadsyou can read of many folks with this issue.

http://www.hyundai-forums.com/ad-201...mp-issues.html
http://www.hyundai-forums.com/ad-201...at-recall.html


Like I said, the issue is mainly when the outside temperature is 5 DEG C or less, for the late spring to now (summer) the needle will have a linear rise with no change and once it hits normal operating temperature , it will stay there.

I do not believe there is any air in my coolant system as the over flow coolant bottle will rise and fall during the heating and cooling of the coolant (very normal). The coolant level in the bottle is with in specification (above MIN at cold.)

Have you seen this issue, is there any service bulletin(s), campaign , or any other technical information you have that notes this issue and or a fix?

Do you think this is a hardware issue or a possible software issue?..

Is the fluctuating temperature reading in these colder months normal? If so, how is this considered normal from an engine design and operation perspective?
--------------------------------------------------

The tempature outside has been generally above 5DegC, but there has been a few days where it was below 5DegC, and I again experience during the cold to normal operating temp the temp and coolant will drop during the coolant temp rise to normal operating temp, so replacement the ECT really didnt help in this regards to which leads me to my question for you Lux..

If this coolant temp wave form is considered normal. I am experiencing and seeing with my live data, during the warm up process from cold start to normal operating temp, the coolant temp will drop a few degrees and then start to rise again and this may happen once with in this period, or a hafl a dozen as it random. Would this be considered normal for this design? and if so, why as I would think this would be a potential emission issue as the engine has not reached it normal operating temp for max fuel efficiency and minimal emission output.

Would you happen to know what is considered normal rise time (warmup) for this motor from cold start?.. I found that if the outside temperature is less than 20DegC, it takes an average of 20min to get to around 90-100degC... above 20degC, it will be 10min to 15min...

Thanks LUX!!!!



Quote:
Originally Posted by Lux View Post
I was a Hyundai automotive service technician until last year, so I will chime in.

A technical service bulletin is presently live (since 2016 August) for certain 2017 Hyundai Elantra models . I know, with certainty, that the the campaign affects Hyundai Elantra AD frame code. The GD frame code for Elantra GT models are not likely affected. I can't remember.

The campaign addresses erratic or unresponsive behaviour of the newly equipped electronically controlled thermostat. The ensuing symptom is excessively prolonged or delayed engine warm up, sometimes producing the diagnostic trouble code P0128. The repair is a new thermostat and housing complete assembly covered under warranty. The cost of coolant is not covered; technicians are expected to recover lost coolant from the engine during the operation and refill the cooling system with it. Common sense would oppose that... New coolant can be requested at the customer's expense.

Electronically control thermostats are employed to confer computer control over thermostat activity. By moving away from mechanical thermostats, engine emissions can be more tightly controlled by influencing combustion temperature by water temperature. Electronic control failure from the in-built thermostat heater element will regress it to mechanical control, anyway. So, there is no risk of catastrophic engine damage from runaway water temperature.

Your undulating waveform in water temperature is normal for this type of system. The engine ECU must observe changes in water temperature in accordance with cyclic duty of the thermostat heater to verify its operation. This is a self-monitoring, self-diagnosis strategy.

Comfortably speaking, until now, the ensuing overheating caused by conventional thermostat failure may not always be caught in time. So this new feature could be seen as a blessing with regards to self-preservation.
CB900F2 is offline   Reply With Quote
Old 10-18-2017, 08:29 PM   #4
CB900F2
 
Drives: 08 Sedan
Join Date: Oct 2008
Location: Toronto
Posts: 301
HI Lux

Here is a graph after I had the ECT replaced, and you will see during the warm up from cold start, the drop in temperature before it gets close to 90-100DegC.. It was in Aug I had it done, and outside was still around 28Deg C, and it still took 17min to get to 90DegC...

But look at the drops in coolant temp at time 4.7m, and then 6m, 8m, and a big drop at 14min..
CB900F2 is offline   Reply With Quote
Old 10-18-2017, 09:40 PM   #5
Lux
 
Lux's Avatar
 
Drives: NCP91
Join Date: Jul 2012
Location: Markham, Ontario, Canada
Posts: 114
I'm looking at your new data capture and, from the waveform, I would say that it is normal-- or at least passable-- and I will explain why.

There are no expansive drops in the water temperature during warm up cycle. It is normal for many cars to have a rippling water temperature, at all heat ranges, due to: 1) coolant is not universally the same temperature as there will be hot and cool volumes passing through the sensor; 2) the water temperature sensor is a thermistor, but the ECU is programmed (sometimes poorly) with only a fixed ohms-per-degree map that can sometimes be coarse (3.8 to 3.7 ohms might specify as 2.6 centigrade); and 3) engine load and combustion are in constant flux, regardless of whether it is driven or idling, an imperfect system.

Even pinning the accelerator on a YF frame Sonata Turbo will provoke the same billowy water temperature waveform during warm up and I can confirm that is on known good engines using conventional thermostats. So, I would leave be the warm up behaviour for now.

Regarding the at-operating-temperature behaviour, I am more convinced that the undulations are either a normal self-diagnosis strategy or the intervention of the cooling fan. How and when else would the ECU know during normal vehicle operation that the thermostat and its heater are working? It looks normal because the undulations are mostly in phase (same y over same x), and this tells me that the ECU has commanded an action (cooling fan or thermostat). However, I would need different parameters on the graph to confirm that, which, perhaps, only a Hyundai GDS scan tool will congruently decode: water temperature, thermostat heater duty cycle, calculated engine load, and cooling fan state.

On the flipside, it could also be an ECU logic fault that Hyundai incorrectly addressed with a superceded thermostat assembly. It wouldn't be the first time, either. I had been on and off the phone for years with head office's technical support about an ECU cooling fan logic improvement on MD/UD Elantra that gave a contradictory outcome under certain conditions: fans didn't turn on at all due to a programming error and overheated the engine.

But, I'll err on the first suspicion: looks normal.

P.S.: 140 km/h in an Odyssey looks like a midnight dash on the 407.
Lux is offline   Reply With Quote
Old 10-18-2017, 10:34 PM   #6
CB900F2
 
Drives: 08 Sedan
Join Date: Oct 2008
Location: Toronto
Posts: 301
Thanks a lots lux!!!

Really appreciate your feedback!!

Very informative !!

Are you still working as a tech as you mention you were a Hyundai tech ?

I am in Vaughan. .. do you know of any Hyundai tech(s) that you would trust with your own car? Trying to find a tech that I can deal with that has the kind of insight and skill set like yourself ..

P.s. Our 06 Odyssey being the boat that it is , surprisilng it can getup and boggie if it needs too.. :)





Sent from my Lenovo TB-X103F using Tapatalk
CB900F2 is offline   Reply With Quote
Old 10-19-2017, 10:15 PM   #7
Lux
 
Lux's Avatar
 
Drives: NCP91
Join Date: Jul 2012
Location: Markham, Ontario, Canada
Posts: 114
I left Hyundai last year. A final-year Korean apprentice who worked under me moved to Burlington Hyundai shortly after, and he's the only person I'd give a recommendation for. He has the same desire as I to pursue sometimes frustrating electrical or logic faults.
Lux is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Consumer Reports First Look at 2011 Hyundai Elantra cdavidhess Off-topic / Other Cars / Everything else Discussions 0 12-22-2010 06:11 PM


All times are GMT -4. The time now is 11:27 AM.




YarisWorld
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.