Heating system has stopped functioning

[#899]

My roadster 2,5 decided to go cold on me.
That one morning you really need the heater to work is of course when «Murphy’s law» decides it should stop working.
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.
Could it be a blown fuse?
Anyone who can give me pointers?
It has worked very well up until now.

 

[Oricle]

Are you getting any VDS error or debug codes?

 

[#899]

Are you getting any VDS error or debug codes?

Nope
Just cold air

 

[petergrub]

Could it be a blown fuse?
Anyone who can give me pointers?

I had another gentleman contact me with the exact same issue. I'm figuring it's likely a problem in the HVAC Controller because that's where the high voltage for the PTC heater is controlled.

Since you aren't getting any error codes on the VDS, is your alert text in end user mode or debug mode? There are some HVAC errors that only appear in debug mode. Then again, I'm looking at the HVAC error list and I'm not seeing an error for the PTC.

 

[pschubert61]

My Model S had aircon and heat problems that were in extreme heat and cold fixed by using phone app to start the heat and A/C. Once the extreme heat (usually when it happened) passed it was fine. The heat same thing. I'm waiting for the deep freeze to hit to see if it returns.

 

[X.l.r.8]

There you go, use the phone app to start the heat. Problem solved










Where is the phone app ?

 

[gregd]

Where is the phone app ?

Same place my phone is. At the end of my arm.

 

[#899]

I had another gentleman contact me with the exact same issue. I'm figuring it's likely a problem in the HVAC Controller because that's where the high voltage for the PTC heater is controlled.

Since you aren't getting any error codes on the VDS, is your alert text in end user mode or debug mode? There are some HVAC errors that only appear in debug mode. Then again, I'm looking at the HVAC error list and I'm not seeing an error for the PTC.

Everything seens ok except for lack of hot air. Will change a few fuses today and see what happens.

 

[supersnoop]

My Model S had aircon and heat problems that were in extreme heat and cold fixed by using phone app to start the heat and A/C. Once the extreme heat (usually when it happened) passed it was fine. The heat same thing. I'm waiting for the deep freeze to hit to see if it returns.

Same place my phone is. At the end of my arm.

We’re in the Roadster forum here, so there’s no phone app (unless you’ve purchased and installed OVMS), and there’s no way to remotely trigger the HVAC in this car.

 

[gregd]

We’re in the Roadster forum here, so there’s no phone app (unless you’ve purchased and installed OVMS), and there’s no way to remotely trigger the HVAC in this car.

Exactly. At the end of my arm are my fingers. They work great on the knobs on the car's instrument cluster.

But this does bring up a question... Does the fan knob physically control current to the ventilation motor (as in an ICE), or does it tell the car's computer to turn on the fan? If the later, we should be able to control this via the OVMS, no?

 

[petergrub]

But this does bring up a question... Does the fan knob physically control current to the ventilation motor (as in an ICE), or does it tell the car's computer to turn on the fan?

Nope, the HVAC controller measures the rotary position of the knobs and commands the system accordingly. Theoretically, the HVAC could be commanded via the CAN bus.

 

[gregd]

Nope, the HVAC controller measures the rotary position of the knobs and commands the system accordingly. Theoretically, the HVAC could be commanded via the CAN bus.

Ah, excellent... Do you (anyone?) perchance happen to know what those CAN messages are? Also, which CAN bus? The OVMSv3 now has access to the others, and I hear the C compiler calling me...

Further wonder... Could said control work while charging? It would be really nice to have some environmental control (heat and/or cool) running during long charging stops, or was that not allowed for a reason?

 

[petergrub]

Do you (anyone?) perchance happen to know what those CAN messages are? Also, which CAN bus? The OVMSv3 now has access to the others, and I hear the C compiler calling me...

Perchance. The HVAC resides on the ESS CAN bus. Also, I enjoyed writing in C over Java back in college. Lately I've been playing with C# in windows forms. If you start a project in Git, I'll contribute where I can.

Further wonder... Could said control work while charging? It would be really nice to have some environmental control (heat and/or cool) running during long charging stops, or was that not allowed for a reason?

I don't believe so because the battery commands control of the HVAC system to thermally manage it's heat production during charging.

 

[JohnGarziglia]

My roadster 2,5 decided to go cold on me.
That one morning you really need the heater to work is of course when «Murphy’s law» decides it should stop working.
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.
Could it be a blown fuse?
Anyone who can give me pointers?
It has worked very well up until now.

Had the same issue a year or so ago but it was intermittent in that if I stopped the car and turned it off, and then turned it back on, the heat resumed. It was the High Voltage Controller needed to be replaced. The cost of the part then was $1374.48 with an additional $140 labor charge. It was Tesla Part No. "1014547-01-A - ASY, CTRLR, HVAC, PTC 400V, LHD"

 

[#899]

Had the same issue a year or so ago but it was intermittent in that if I stopped the car and turned it off, and then turned it back on, the heat resumed. It was the High Voltage Controller needed to be replaced. The cost of the part then was $1374.48 with an additional $140 labor charge. It was Tesla Part No. "1014547-01-A - ASY, CTRLR, HVAC, PTC 400V, LHD"

Thank you

 

[gregd]

Perchance. The HVAC resides on the ESS CAN bus. Also, I enjoyed writing in C over Java back in college. Lately I've been playing with C# in windows forms. If you start a project in Git, I'll contribute where I can.

No new project necessary. I was thinking of the existing OVMv3 project; it's already on Github. That said, I'd rather not write to the ESS CAN bus, given its critical role in keeping the car running safely. Monitoring, sure; controlling, probably not.

I don't believe so because the battery commands control of the HVAC system to thermally manage it's heat production during charging.

Yeah, I was thinking the same. But then the HVAC system also cools the battery in the summer when driving hard, so it appears to have the capacity. And in the winter, it would be turning on the heat while charging, and that's two different systems, assuming one can get power to the heating unit while pushing electrons into the battery.

I believe this all works on the newer cars, so there must have been a reason not to do it on the Roadster, either for electrical plumbing or capacity reasons. It's just annoying, given the longer charging times, that we can't sit in the car and be comfortable.

 

[petergrub]

Yeah, I was thinking the same. But then the HVAC system also cools the battery in the summer when driving hard, so it appears to have the capacity.

Anecdotally from dad driving his Roadster in the middle of Phoenix summers, he used to complain about the battery taking the HVAC system from him when the battery needed it more than him. The A/C would cut out and he would get a warning about the power being reduced. It would appear the battery hogs the HVAC system during charging and driving in extreme temperatures.

And in the winter, it would be turning on the heat while charging, and that's two different systems, assuming one can get power to the heating unit while pushing electrons into the battery.

True. The PTC heater is powered by the high voltage HVAC controller, while the battery coolant heater is 12V. I don't know if there's any reason the Roadster was programmed to disable the HVAC controller while charging the battery. I will investigate.

 

[#899]

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?

 

[gregd]

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?

No, the heat in a Roadster is a simple ceramic resistive element. No moving parts except the fan, which you said was working. Either the heater element is not getting power, or it has opened up and is not working.

When you turn on the heat to high (crank the knob all the way to the right), does the amps display change? Mine can pull 10A when it first starts up. If it does, then it may be the baffle is stuck. Change the cabin air flow control (foot vents, top vents, defrost) knob back and forth and see if it un-sticks. That happened once to me, if I recall.

 

[#899]

No, the heat in a Roadster is a simple ceramic resistive element. No moving parts except the fan, which you said was working. Either the heater element is not getting power, or it has opened up and is not working.

When you turn on the heat to high (crank the knob all the way to the right), does the amps display change? Mine can pull 10A when it first starts up. If it does, then it may be the baffle is stuck. Change the cabin air flow control (foot vents, top vents, defrost) knob back and forth and see if it un-sticks. That happened once to me, if I recall.

I will try this today
Thanks