i-Miev Cabin Heater stop heating

[Andreb1160]

Hi, the cabin heater of my i-Miev stop heating after a few minutes. The fan does not stop, it continues blowing colder air. If I stop the car and turn it OFF, then turn it back ON the heater will always continue heating for a few minutes but will stop heating after a while. My guess is that when the liquid is hot the heater turns OFF and never turn ON again when the liquid is colder. If I reset it by turning the car OFF and ON it will heat again until the liquid is hot then it will turn OFF and never turn ON again.

Does anyone has experience this problem or know what needs to be changed?

Thanks,
André

 

[MickeyS70]

Hi André
Sorry to hear about your troubles, you mentioned one possibility but there are a few others, therefore before pulling everything apart it might be a good idea to get yourself an OBD dongle and app to pinpoint the problem.

OBDZero for example will show a lot of info about the state of the heating system (temperature sensors, heater power, blower settings etc)

Mickey

 

[Andreb1160]

Thanks Mickey, I will buy an OBD dongle and see what information I can get from OBDZero.

Is OBDZero compatible with any dongle?
Any suggestion for an OBD dongle?

 

[MickeyS70]

Thanks Mickey, I will buy an OBD dongle and see what information I can get from OBDZero.

Is OBDZero compatible with any dongle?
Any suggestion for an OBD dongle?

I use an OBDLink LX, it’s rather expensive these days but works reliably with all dedicated triplet apps and other EVs, see user manual for alternatives:

https://github.com/DavidCecil50/OBDZero

 

[TobyGadd]

Is there enough fluid? Is the pump working properly? Just pop the hood and watch the reservoir: there should be a lot of swirling throughout the cycle, If you have an IR thermometer, you can point it at the reservoir to see how hot the fluid is getting, which should help determine if one of the temperature sensors is failing.

 

[Andreb1160]

Is there enough fluid? Is the pump working properly? Just pop the hood and watch the reservoir: there should be a lot of swirling throughout the cycle, If you have an IR thermometer, you can point it at the reservoir to see how hot the fluid is getting, which should help determine if one of the temperature sensors is failing.

Yes the liquid reservoir is full.
Yes the pump is working, I can see a lot of swirling in the reservoir
I measured the temperature of the liquid with an IR thermometer and the temperature is between 60 C and 62 C
BUT
When it stops heating the pump stops too, no more swirling in the reservoir
Then if I turn OFF the car and back ON, the pump and the heater start working right away.

The time it takes to stop heating seems random for now, I am trying to find a setup, a sequence to make it stop heating easily.
I will have an OBD dongle to get more information in a couple of days.

 

[TobyGadd]

Seems like you've covered the basics. Hopefully the error codes will help you make a solid diagnosis.

 

[Fisher]

I have the same problem with my Peugeot Ion.
It randomly stops heating with the same simptoma.
I have OBD dongle and OBD Zero too.
But, unfortunately, i couldn`t find any temperature sensors, connected to the heater in OBD Zero.
Only information available is the heater power consumption. When the pump stops, heater power consumption decreases to minimum, but it still works.
Now need to find out why the pump stops.

And another important note: it happens only on the road, in motion. Today I`ve tested it in parking mode, everything worked OK for about an hour.
So, I think, something switches off the heater pump only when the car rides.

 

[Andreb1160]

I have the same problem with my Peugeot Ion.
It randomly stops heating with the same simptoma.
I have OBD dongle and OBD Zero too.
But, unfortunately, i couldn`t find any temperature sensors, connected to the heater in OBD Zero.
Only information available is the heater power consumption. When the pump stops, heater power consumption decreases to minimum, but it still works.
Now need to find out why the pump stops.

And another important note: it happens only on the road, in motion. Today I`ve tested it in parking mode, everything worked OK for about an hour.
So, I think, something switches off the heater pump only when the car rides.

Me too it is very difficult to reproduce the problem when the car is parked and warm but it happened.
My car is parked in a heated garage. and I noticed that when the car is warm the heater pump almost never stop even when I go out and drive, but if I leave the car outside (sub 0C) for a while, it does not take long before the pump stop while driving. I will try when the car is parked and cold to see how long it takes before the pump stop without driving.

So my observation is the more the car is cold the less it takes before the pump stops, which is very inconvenient because when it is very cold that's when I need more heat. I am in Canada so winter is sometimes very cold here.

 

[MickeyS70]

I have OBD dongle and OBD Zero too.
But, unfortunately, i couldn`t find any temperature sensors, connected to the heater in OBD Zero.
Only information available is the heater power consumption. When the pump stops, heater power consumption decreases to minimum, but it still works.
Now need to find out why the pump stops.

Apologies, I have used various available apps/dongles and got confused what does what, you are right OBDZero displays heater power but only CanIon (or Diagbox) will show you a heater temp history. It plots the values of the water temp sensors (in/out) that are located inside the PTC heater.

There is a very detailed discussion about the heating circuit below (use google translate) that may give you some pointers.
https://www.goingelectric.de/forum/viewtopic.php?t=37949

Mickey

 

[Andreb1160]

Yesterday it was cold, less than 0C, I drove the car to a place where I left it outside so the car cooled down to the outside temperature. Then I drove a few km and noticed the heated stopped while I was driving. I stopped and turned off the car then back on, surprisingly, for the first time, the heater did not heat at all, I cycled the car ON and OFF many times and the heater never heated again. Back home I connected the car to the charging station and started the heater with the remote control. The heater started heating right away and was heating correctly non-stop.

today I did the following test, I parked the car outside at -1C for 2 hours. Then I started the car and the heater. The heater was heating but it stopped after less than 4 minutes. Turned OFF the car then back ON. The heater was heating again for less then 4 minutes. I did this 3 times and the time it takes for the heater to stop heating is the same.

 

[MickeyS70]

Turned OFF the car then back ON. The heater was heating again for less than 4 minutes. I did this 3 times and the time it takes for the heater to stop heating is the same.

Now that’s exactly the behaviour as mentioned on the German forum, if the car thinks there is something wrong with the heating circuit it does an emergency shutdown after about 4min, only way to reset that timer is turning the car off/on again.

You should be able to observe a relevant DTC after the heat turns off with your OBD dongle. It’s suspected that this is caused by a fault in PCT heater control circuit as replacing the heater itself didn’t fix the problem.
Mickey

 

[Andreb1160]

I have OBD dongle and OBD Zero too.
But, unfortunately, i couldn`t find any temperature sensors, connected to the heater in OBD Zero.
Only information available is the heater power consumption. When the pump stops, heater power consumption decreases to minimum, but it still works.
Now need to find out why the pump stops.

Apologies, I have used various available apps/dongles and got confused what does what, you are right OBDZero displays heater power but only CanIon (or Diagbox) will show you a heater temp history. It plots the values of the water temp sensors (in/out) that are located inside the PTC heater.

There is a very detailed discussion about the heating circuit below (use google translate) that may give you some pointers.
https://www.goingelectric.de/forum/viewtopic.php?t=37949

Mickey

I cannot find CaniOn on Gloogle Pay Store, is this App still available somewhere?
Which app should I use if CaniOn is not available anymore?
Thanks

 

[MickeyS70]

I cannot find CaniOn on Gloogle Pay Store, is this App still available somewhere?
Which app should I use if CaniOn is not available anymore?
Thanks

You’re right again, it’s gone from the Play Store but if you search “CanIon APK” you should be able to download the latest version (152, I think). The app is fussy when it comes to OBD dongles and doesn’t display DTCs but it’s the only one I know to plot heater water temperatures.

Use “Car Scanner” or similar to read/clear fault codes.

See below for further info
https://myimiev.com/forum/viewtopic.php?t=4936

 

[Andreb1160]

Ok, I have got my dongle and bought car scanner Pro so I can graph inlet and outlet liquid temperatures and heater power.

First of all, it seems that there is an offset of 20 degrees between the temperatures I am reading with car scanner and the real temperature. The car has been at 17C for the whole night and the measured temperatures are 37C in the morning. And the higher temperature of the liquid measured with my IR thermometer was around 60C and my max reading with car scanner is about 80C.

Here is an example of my readings:
https://drive.google.com/file/d/1yYg9XLiC9caNgPog20VXpNKkxNsp9oPb/view?usp=drive_link

Here is what happened during this test:

I plugged the car on the charger and pre-heated it. Then I went out for a drive, outside temperature about -6C.

In the first 15 minutes I was driving in town at less than 50 km/h. The heater was between 3000W and 5000W and the liquid temperature was quite stable just below 80C (or 60C in real).

Then I went on the highway, driving at 100 km/h. As you can see the heater was still heating with 5000W but the liquid temperature was rapidly decreasing. The heater was unable to keep the liquid temperature around 80C. Then after a certain time the heater has been shut down to around 1100W (I noticed later that when the heater is shut down the pump is stopped too).

In the German discussion you gave me as a reference, he was talking about a 3 degrees offset between the inlet and the outlet liquid temperature. I observed this 3 degrees offset and as long as the heater can maintain this 3 degrees offset the shutdown does not seems to happen. In my other tests each time the shutdown was happening this 3 degrees offset was absent for more than 3 minutes.

Here is another example, this time not driving, just parked outside at -6C.

https://drive.google.com/file/d/1LouvnFzF8h2sXU-WaPiVd1mI7uevmkx6/view?usp=drive_link
Just started the car when the liquid was colder. As you can see on the first graph the heater was unable to get the 3 deg difference in the first 3 minutes and it did shut down,

Restarted the car and was continuing the test on this second graph
https://drive.google.com/file/d/1Oi21t12qtnxwXw2RwnAA20Kx0P9-2Bzt/view?usp=drive_link
Here the heater can get the 3 degrees difference and do not shut down.

Here is a third example, just parked outside, not driving, but starting the test with a colder liquid temperature.

https://drive.google.com/file/d/1HfVeDQV1IKAD2xYJ_O2WjFU6PHZqXlYL/view?usp=drive_link
https://drive.google.com/file/d/1G4SrDjUJT_lijq8Wgkt9ZMLpMDllFkpk/view?usp=drive_link

As you can see, starting with a colder liquid temperature, the heater has a harder time to obtain the 3 degrees diff and keeps shutting down every three minutes. But if I continue restarting the car, the liquid is slowly getting warmer and warmer and finally get to a point where there is a 3 degrees difference and the shutdown stops happening;.

But this equilibrium is fragile. If I turn the air fan speed to its maximum, with the air coming from outside (very cold), then the heater can't keep up, liquid temperatures start moving down and heater shutdown start happening again.

The maximum heater power measured is 5880W. I don't know what is the maximum. Is my heater not heating enough?

I also read a DTC code for the heater #2 : B1108
I don't know what it exactly means. Found different meaning on internet.

I am thinking about calling a few dealers to see if they fixed this problem in the past. I don't want to bring my car there if they never fixed this problem. Because if they park the car in the workshop, the heater won't shutdown as it does not shut down when I test it in my garage.

André

 

[MickeyS70]

Excellent analysis, looks more and more like the issue our German colleague is describing, even down to the same fault code B1108, some troubleshooting hints below

https://myimiev.com/forum/viewtopic.php?t=5197

Faulty PTC heater (although replacement didn’t solve the problemfor our German friend) or AC control Unit would be my guess 50:50:80….

 

[kiev]

Good research and report, i had never heard about the 3 deg delta before, but it makes sense.

Some ideas to try:
Put some cardboard to block off the radiator and keep your heat from getting lost, especially when it is so cold outside (and if driving fast); also don't pull in outside air, use recirc; also use defrost instead of heat.

 

[MickeyS70]

Put some cardboard to block off the radiator and keep your heat from getting lost, especially when it is so cold outside (and if driving fast); also don't pull in outside air, use recirc; also use defrost instead of heat.

I always thought motor cooling and cabin heating are independent circuits, but Kiev is right (as usual), they meet in the HVAC module:
Cabin/outside air is blow trough (cold) evaporator before hitting the PTC heater

See diagram below
https://www.flickr.com/photos/siimos/6136950602

 

[Fisher]

Since I have the same problem as Andreb1160 with my Peugeot Ion, I`ve also tried to catch the moment when it happens.
On my opinion it is something that shuts off the heater pump. And since there is no circulation, heater also reduces power to minimum.
I`ve also noticed that initial temperature on the heater sensors is 20 degree higher than actual one.
It means that when i see 18 degree in the heater with HOB Drive, actual temperature outside is below 0, about -2 -5. Sibce the car stays outside, heater temperature should be close to outer one.
What I have done: first of all I changed the heater pump relay (just had one spare from Ford, but only 20A, not 30). It helped a little. Heater started to work a bit more stable in mid mode (about 4kw) - 3rd heat position. There were only 2-3 switch offs in this mode. But in high power mode and PUSH MAX mode nothing changed.
Next - I want to buy toyota or omron 30A relay. Hope it will help.

And the DTC code for the heater #2 : B1108 as I see is "Heating water circulation pump"

 

[MickeyS70]

And the DTC code for the heater #2 : B1108 as I see is "Heating water circulation pump"

Curious where you get the above from as I can only find this in the workshop manual:

“This code is set when the outlet temperature of the heater does not raise to a temperature higher than the inlet temperature by 3°C for more for 30 seconds or more.”

Did you plot inlet vs outlet temperature when your problem occurs?

Not sure what CAN codes generic apps use to display these temperatures, there may well be an offset that is only corrected using dedicated apps (CanIon, MUT3, Diagbox) but shouldn’t matter here as only relative values are used.