AC Blowing Hot Air

AC Blowing Hot Air

Sorry if this has been posted and answered before...I have a brand new (less than 4k miles S90D) and today my AC stopped blowing cold air, even tough it worked perfectly all day. Was not overly warm here today , about 84 degrees. Made 1 stop and when I returned to my car and started driving, it was only blowing warm air. Any help would be greatly appreciated. | April 28, 2017

Better than all the hot air we get from politicians :)

Ok, I'd first try a reboot (hold both scroll wheel in for about 15 seconds until the main screen goes black. Reboot takes about 60 seconds, and may take another 20 seconds for HVAC to come back online.

RKMCD66 | April 28, 2017

Thanks TeslaTap...tried that to no avail.

murphyS90D | April 28, 2017

Is it a very humid day? The evaporator coils my have frosted over and only outside air is getting through. The cure is to turn it off to let the frost melt.

lilbean | April 28, 2017

I had an S loaner that did this and it turned out the AC setting switched to off.

steveg1701 | April 28, 2017

I had this problem a month or so ago, in addition to a reboot (no help) I tried checking the manual settings, and even turning off auto and cranking it down to max. Wound up going to SvC, they ordered some sort of temperature sensor while further diagnosing, then said it was a firmware problem and fixed it with an update. If you're a distance from SvC you might try calling them and asking if they can research and remote you the updated firmware?

revrev4ruach | April 28, 2017

Same thing happened to me about a month after taking delivery. I called the SvC who made an appointment for me to take it in the next day, but after sitting overnight, the problem resolved itself. It hasn't blown hot air again in the six months I've had it. No explanation from the SvC other than the software (or A/C temp sensor) can reset after the car sits for awhile.

Sleepydoc1 | April 28, 2017

My X last summer had AC stopped blowing cold air also. The coolant pipe was kinked in O ring and had a leak. They fixed it and has been ok since.

vp09 | April 28, 2017

lilbean | April 28, 2017 wrote: "I had an S loaner that did this and it turned out the AC setting switched to off."

That happened to me in my car a couple weeks ago.

Bill_75D | April 29, 2017

RKMCD66 - I have had two separate instances of this with my car. Both times the A/C failed to work when I first started the car. It had been working fine previously. Rebooting the car did not help either time. The issue solved itself the first time by parking and shutting the car down and then restarting. The second time it happened on a long road trip and repeated stopping and starting didn't work. Magically after parking overnight it worked fine the next morning.The service center guy thought it was probably a software bug and manually loaded 17.14.35 and so far it has been working fine.

RKMCD66 | April 29, 2017

Was back to working as normal this morning, so nothing mechanical. Also, soft reboot did not work last night. Some bug obviously. Emailed Tesla and they still haven't responded 24 hour later | April 29, 2017

@RKMCD66 - sounds more like a freeze up (that melted after a while) than a bug. A few others have seen this, but it's never happened to me.

rdr1rx | April 29, 2017

This is normal operation. If hot/humid outside, AC can divert from interior circulation to the traction battery to keep it running at optimum temperature. (This is mentioned in the Owner's Manual). I have noticed this occurrence (rarely) when it's > 90F with AC on LO to 67F. It's analogous to an ICE where the electric radiator fan(s) switch on to keep the block from overheating when airflow through the front bumper is minimal at best (like in traffic).

tes-s | April 29, 2017

I don't think I've experienced that diversion - thought there were separate cooling systems for the cabin and battery.

Guess we got lucky going through Death Valley - cabin was nice and comfortable when it was a cool 118F outside.

WATTGAS | April 29, 2017

RKMCD66 - I had the exact same issue about 2 months ago. Stopped working during the day, reboots didn't help, parked the car for 2 hours and then it worked fine. SvC checked the logs and then replaced the electric chiller in my car (Dec 2016 delivery S90D). Good luck, be sure to get the SvC to look at it.

jgardner | April 29, 2017

I had this same issue on a Dec 2016 S 90D. Had to replace the battery chiller. It has been fine since the replacement. I live in FL so you definitely notice when the AC is out.

RKMCD66 | April 30, 2017

Tesla finally answered my email, and their first question was "Did you have temp on low and fan on 11?" Which I actually this must be a known issue.

Bill_75D | April 30, 2017

My temperature was on 72 and fan on 7 both times, and the outside temperature was 93° the first time and upper 80's the second time. I doubt I had a freeze-up. If so, I'm screwed with the Phoenix summer coming. | April 30, 2017

@Bill_75D - Yep, hard to imagine a freeze up in Phoenix. Plenty of S cars in Phoenix and I don't remember others reporting an issue. I'd keep a close look on it and talk to service if it happens again.

@tes-s "thought there were separate cooling systems for the cabin and battery"

Not exactly. There is one HVAC system (compressor, radiator, etc.) and valves control the direction of the cooling to the battery, cabin or both. It can also heat one while cooling the other. That said, the battery takes priority. I in four years, I noticed it once seemed reduce cabin cooling on a hot day on a long hill climb at 70 mph. So if the battery needs extra cooling, it may temporarily reduce cabin cooling - but this is usually minutes, not for an entire trip.