Heating system has stopped functioning

[ackeller]

So maybe someone can give some pointers.
I have checked fuses and all is good so far, bit no heat coming throigh.
No messages
Just no heat.
Is it the hvac then?

I had the same issue yesterday. This morning, I turned off the iPhone bluetooth, went to the car and open it with the my Tesla card. The heat came back on? I leave my system in auto. Found this information on TMC.

 

[X.l.r.8]

Ahem, this is the roadster section. These mythical things you speak of sound great. My EAP is holding the steering with my knee while I wrestle my drink into the ONE cup holder. Leaving the system on auto for us is leaving the car unlocked and flipping the filler flap 12 times.

 

[#899]

I will try this today
Thanks

So I checked for amp change while turning the temp knob. No change.
Fans are running, but only blowing cold air still.
Any other hacks / ways to figure out if this is fixable without spending a small fortune at a SC?

 

[gregd]

Hmmm, ok. I assume that the "heating" indicator on the control panel is coming on when you get into the right-hand side, right? That tells me that the car thinks it's pushing power to the heater core (the lamp is computer driven, I believe, not hardwired), but the heater's not taking the juice. Assuming that a power supply failure would be caught by the car's own internal monitoring, I would conclude that either the heater core has failed (open circuit), or the wiring (connector?) is broken or disconnected.

I don't know where the heater core is located. It's a simple ceramic resistive element, theoretically pretty robust...

 

[backmost]

Are you sure all the fuses are good?

 

[CSPHD]

So here the other day I got no more heat from the system. I can only get cold air. The system works, but no heat.
Anyone who can give me pointers?

I have the same problem in my 2.5. The HVAC system has been the weakest link of my car. The HVAC has been replaced twice (the bit under the hood, not the interior control panel) because the AC quit cooling. The third failure was the heating subsystem exactly as you've described, blower runs but no heat. The AC is working fine.

SC said a sensor was malfunctioning and causing the heating control to think it was too hot, so no heating. Quoted me $2,100 to replace whole assembly so I just use the seat heaters now and dress warm.

No heat and crappy TPMS make me a little sad everytime I drive an otherwise exhilarating car.

 

[#899]

I

Are you sure all the fuses are good?

i believe I have tried all the fuses helping with the heating system. But will keep exploring.

 

[#899]

Hmmm, ok. I assume that the "heating" indicator on the control panel is coming on when you get into the right-hand side, right? That tells me that the car thinks it's pushing power to the heater core (the lamp is computer driven, I believe, not hardwired), but the heater's not taking the juice. Assuming that a power supply failure would be caught by the car's own internal monitoring, I would conclude that either the heater core has failed (open circuit), or the wiring (connector?) is broken or disconnected.

I don't know where the heater core is located. It's a simple ceramic resistive element, theoretically pretty robust...

Hi
Heating indicator lifghts up when I turn the knob.
I had to pull the vds cables ( I believe it was called) a while back to reset the system. As the car shut down on me.
Heating worked fine after that but could there be a connection?
And where would I look for lose connections?
Than you for grest input.

 

[JohnGarziglia]

Hi
Heating indicator lifghts up when I turn the knob.
I had to pull the vds cables ( I believe it was called) a while back to reset the system. As the car shut down on me.
Heating worked fine after that but could there be a connection?
And where would I look for lose connections?
Than you for grest input.

I recall looking into as much as I could to learn about the heating elements in the Roadster back when I had a similar issue. My recollection is that there is a fuse link or a similar type of temperature control shutoff at the bottom of the heating assembly that could fail. I briefly considered trying to take the assembly out of the car to see if it was something that was easily repairable once the assembly was out of the car but the removal of the assembly looked to be too much work for me to do on my own so I did not. You might do a comprehensive search on this forum as I recall learning about this assembly somewhere from an early post here years ago.

 

[backmost]

I'll see if the service manual has any information

 

[gregd]

I had to pull the vds cables ( I believe it was called) a while back to reset the system. As the car shut down on me.
Heating worked fine after that but could there be a connection?

Probably not related. None of the high voltage / high current goes through those connectors, and because the heating indicator comes on, we know the computer knows what is going on.

I think JohnGarzigila is probably on the right track, unfortunately.

 

[dhrivnak]

My guess is you have a bad heater core or what Tesla calls a PCT. Hopefully you can see the attached PDF

 

[Logticom]

Same problem here I found out yesterday. System works, but only cold air.
I will try some things mentioned in this thread.

@#899 and @CSPHD (or anybody else):

Any luck with changing fuses or any thing else you did?
Are all the fuses to check under the dashboard?
And how can I find out which fuses to check for the HVAC / PTC components?

Thanks!

( I am lucky it is getter warmer outside here in The Netherlands...)

 

[petergrub]

Any luck with changing fuses or any thing else you did?
Are all the fuses to check under the dashboard?
And how can I find out which fuses to check for the HVAC / PTC components?

There's a 10A fuse inside the high voltage HVAC controller that provides power to the PTC heater.

The fuse in the dash for the high voltage HVAC controller is #12, 30A. The fuse diagram in the dash says radiator fans because the two radiator fans near the front receive their 12V power from the high voltage HVAC controller.

 

[Logticom]

@petergrub Thanks! Hereby an update. I checked fuse #12 and this fuse is ok. I also checked fuses 23 and 27 and those are also ok.

Is the HVAC controller what is shown on the picture that I have attached?
And is it easy to get to and open up?
(for example on a scale from 0 to 10?)

 

[petergrub]

Is the HVAC controller what is shown on the picture that I have attached?

No. The high voltage HVAC controller is the silver box above it. In the 1.5 Roadsters it is the size of a shoe box, while in the 2.X Roadsters it's much smaller.

To open the 2.X high voltage HVAC controller is about an 7 out of 10. It's not difficult, just tedious because you need to remove more screws than should be necessary to get the internal PCB to slide out.

 

[thefortunes]

Here in the great white north (Wisconsin) it has started to get cold. Turned on the heat last night and was greeted with A/C instead (well, not really, it was just blowing cold air).

Checked the fuses and they are ok. The Heat indicator lights up, but no change in amps drawn. No errors thrown (and I am in diagnostic mode).

As many of you know I'm about 100 miles away from the nearest service center and have no problem working on the car myself (have replaced the insulation, IGBTs, etc.. in the PEM) so looking to save myself a trip if someone can help me troubleshoot.

Thanks!

 

[Logticom]

Hereby an update on my "heating not working issue".
(Everything worked fine on my Roadster, but only no heat when turning the knob to the right (red light did come on))

With thanks to @warden_clyffe we got the heating working after changing the 400v controller with another one.
So the problem was in the 400v controller.
We didn't find out yet what the problem is in the 400v controller...

It was worth the drive of 847 km in one day back and forth from Zwolle (The Netherlands) to Melsungen (Germany):

@warden_clyffe Thanks for helping us out with some "Roadster magic"

@Marius Thanks for sharing almost 2 years of JdeMo experience in one day

@AllEuropeanRoadsterOwners: If you need help with a Roadster problem, @warden_clyffe in Germany is a good place you can go to. After looking at him working on my Roadster, I think he can take a Roadster apart and back together without even using his eyes...

Hereby a picture of 2 Roadster JdeMo charging together in Germany:

 

[janchr]

mine does not work when cabin outlet temp is showing incorrect temperature, (shows about 80C sometime). I would check this first, because heating is obviously stopped when cabin outlet too high.

BTW anyone have idea how to replace cabin outlet heating sensor?

 

[warden_clyffe]

...I think he can take a Roadster apart and back together without even using his eyes...

...didn't you notice ? i kept my eyes close the whole time ;-)

nice having you folks here !