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Help! Air Conditioning problems - Road Trip in Progress!

Discussion in 'Model S: User Interface' started by kruecab, Aug 10, 2015.

  1. kruecab

    kruecab Member

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    Hi there fellow Tesla drivers!

    We are on an epic road trip from our home in San Diego, CA to Vancouver, BC using our 2012 Tesla Model S P85. We are currently on the northbound leg at the Corning Supercharger. Between Vacaville and Corning, we noticed the vehicle seemed to be getting hot and the A/C was not helping. San Diego can get toasty and in 2 years of ownership, the A/C has always done a good job set to 65-67 its stayed nice and cool. Setting it to LO was rare and had to be turned back up after a few minutes because it got so chilly.

    Here are our observations:
    - Started having problems after annual service done at Tesla Service San Diego about 1 month ago. Was hard to tell there was a problem though as it has been fairly cool, but I noticed it wasn't quite as cold as normal.
    - Took it back within a week and they said everything looked good, but adjusted the refrigerant level as it was just slightly off spec.
    - Things have seemed okay since, but its noticeably hot in the car now. Not sure if this is because its hotter now (90F) than it has been or if the problem has gotten worse.
    - Vents are very cold so I think A/C is working.
    - Fan sounds like it's blowing hard
    - But not a lot of air coming out... I suspect some kind of blockage or an internal vent/baffle/air filter is jammed or clogged.
    - Have also seen other threads mentioning a problem with recent software... we are up-to-date (6.2.something) with a update last week. This seems like more than just auto-fan speed though as even with manual controls its really hot in the car.

    Here's what we've tried:
    - Recirculate setting seems to work slightly better than fresh air setting, but not by much.
    - Fan at 11. Still not much air movement. Definitely not like it usually is.
    - Set all combinations of air coming forward, downward, and windshield. Doesn't seem to change much.
    - Tried cycling the Comfort system, no difference.
    - Tried to setup appointment with Portland service for 8/13... They are very busy and will try to fit us in, but it didn't sound encouraging.

    Will try when done Supercharging:
    - Reboot console

    Any other ideas or tips from the community to save our Roadtrip? We are at capacity with myself navigating, the wife driving (I know! but this really plays to our strengths), our foreign exchange student and our two kids.

    Also, any experience with differences between Portland and Seattle Service? We've only used San Diego and they have been okay so for.
     
  2. Cyclone

    Cyclone Active Member

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    Sadly beyond the reboot I have no advice, but it almost sounds like the louvers are stuck closed. So while the fans are blowing like crazy, the air is essentially just leaking around a door into the car, preventing much from getting into the cabin. Good luck! Wish I had some actual advice.
     
  3. Benjamin Brooks

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    Just to confirm (since you didn't mention it), you have range mode off, right? Otherwise HVAC will be severely power limited & poor performing with range mode on.

     
  4. kruecab

    kruecab Member

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    Okay, so after a full charge at Corning (about 1 hr stop), we rebooted dash and console, set to LO and now its blowing hard like normal. Had to turn it up to 66F after about 10 minutes as we had Penguins pecking on the windows to get in! :)

    My concern is that this without determining Root Cause, this is gonna happen again. (IT background showing)

    Cyclone: That is exactly what it felt like. Fan sounded like full speed but just a little air, like it was seeping around the louvers. The fact its blowing now makes me wonder if it was a control issue (not sending proper louvre control commands) or a mechanical one (command received, louvers inoperative). Seems more like the first if it is working now, unless its an intermittent mechanical issue.

    Benjamin: Yes, we checked it was not in Eco/Range mode. I didn't think to try toggling it again as it was in that mode earlier today when it was cool out. I will try that if it happens again.

    Thanks everyone for your help. We'll check in over the next couple days if we have any more observations.

    #VancouverOrBust
     
  5. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    No doubt, but probably not for awhile. I always reboot before any critical mission, as there appears to be memory fragmentation that affects various items (usually maps).
     
  6. ddimit

    ddimit Member

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    If his blowers is going to 11 he's not in range mode, I learned that the hard way. Range mode will limit blower speed to 7 or 8 as i recall.
     
  7. Ingineer

    Ingineer Electrical Engineer

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    It could be that the dampers simply got out of sync and the reboot homes them. I was going to suggest pulling and replacing the HVAC control fuse until I saw the reboot fixed it. I've had this happen in my LEAF on several occasions.

    I wouldn't worry about it. Hopefully Tesla will keep improving the software/firmware in all the systems and fix some of these little bugs.

    Just like I reboot my computer and my phone at least once a week, the Model S is no different, after all it's closer to a PC than a normal embedded system. When in doubt, reboot!
     
  8. Tdriver

    Tdriver Member

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    Electronics (anything using processors) can just become stupid for no reason. A reboot almost always fixes the problem.
     
  9. kruecab

    kruecab Member

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    Thanks for all the replies! I sort of feel silly for making such a big post, but it was REALLY HOT approaching Corning. The rest of our journey today was uneventful and we arrived in Ashland after a top up at Mt. Shasta with no further A/C problems.

    We should have rebooted earlier but we're just playing things a bit cautiously.

    Happy travels!!
     
  10. scot

    scot Member

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    If you hear the blower spinning away, but no air coming out, try to manually change the output (top/middle/bottom) to see if one of the doors directing air is stuck. The car might think the flap is open, when it is not.

    It could also be a blockage on the air intake (if not in recirc mode) or it could be something that was sucked in and is blocking the air filter.

    Just a word of warning, if this keeps happening (low airflow but with fans turned up) you should not continue using your AC. The evaporator coils will stay too cold and could cause the humidity in the air to freeze on the coils. This could cause damage to the coils and would need major repairs as the refrigerant leaked out. I would also be a bit worried about them adding refrigerant as stated in the initial message. The systems are sealed, so any time the system is low, there IS a leak, unless it was low from the factory.
     
  11. mknox

    mknox Well-Known Member

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    This has raised a bit of a flag for me. I had my 50,000 mile service done recently, and one of the things they did was to completely evacuate and re-charge the a/c system. I'm not sure why, because it had been performing very well. In fact, it used to blow the coldest air that I've seen in any of my previous cars. After the service, I could swear it doesn't blow as cold. It still works and cools the car down.
     
  12. scot

    scot Member

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    Ask them why. This isn't a regular service item, though the specs on the total amount of refrigerant in the system may have changed at some point during the products lifespan. If so, the proper way to change the amount would be to evacuate, verify that there is no leakage, then replace it. Either adding or removing the required amount to meet the new specifications for the system.

    Check with the service manager, I'm sure they could give you an answer.

    BTW, as the system gets "low" it can actually seem to get colder. Any number of reasons for it, but it won't be able to cool as much total heat. They could have just found that a slightly higher amount of refrigerant had overall better values, getting lots of air cold while maintaining optimal efficiency.
     
  13. mknox

    mknox Well-Known Member

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    It was on the paperwork as a recommended activity at that interval. They also flushed and refilled the coolant and flushed and re-filled the brake fluid.
     
  14. Ingineer

    Ingineer Electrical Engineer

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    They evacuate the system to replace the desiccant bag located in the condenser. You can't get at it without discharging the system, so that's why. Once the replace the desiccant, they put the refrigerant back in.
     
    • Like x 1
  15. mknox

    mknox Well-Known Member

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    That's exactly what they did. I wonder why, though? I've never had or needed that service on any prior car.
     
  16. Ingineer

    Ingineer Electrical Engineer

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    Mknox, I posted this little anecdote in the autopilot thread, but it may explain why your air doesn't seem as cold:
    Likewise, anytime someone directs our attention to something we tend to over-scrutinize it. Not saying this is the case with your A/C, but it might be.

    - - - Updated - - -

    The A/C in the Model S also cools the batteries so it has more refrigerant and is more complex, and in addition the refrigerant is in contact with 400V high-voltage in the compressor where it cools the motor and it's drive inverter. I suppose they don't want to chance any moisture in there causing problems, as it's not just a bunch of hot grumpy passengers if it fails.
     
  17. mknox

    mknox Well-Known Member

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    Yeah, I get that and honestly wondered if I was just imagining it myself in the first place. Bottom line is that it's working and it could have just been a whole different day with different temperature and humidity levels affecting my perception.

    Good point, and I was aware that it was needed for cooling the battery. I often subscribe to the "if it ain't broke..." philosophy, but maybe "better safe than sorry" applies here.
     
  18. Ingineer

    Ingineer Electrical Engineer

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    Yeah, most A/C system engineers simply design enough desiccant in the system to last it's projected life. Maybe Tesla didn't do this, or found it inadequate after it was put in service. In theory a feature could be added to the HVAC controller firmware to detect ice in the expansion valves and set a DTC.

    Personally I think they should re-engineer the system to add in controllable expansion valves and the reversing valve so the system can function as a heat pump which would drastically cut down on winter power consumption.
     
  19. mknox

    mknox Well-Known Member

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    That would be ideal, and in fact it was originally speculated that this is how they were going to implement it.

    One thing they do is utilize the coolant loop through the battery, motor and inverter to extract heat in the winter. A resistance heater supplements this. I have found on long winter road trips, my consumption is barely off summer levels. It spikes at first, but tapers off as this closed loop gets warmed up by everything running. On short trips, when the car has had a chance to cold-soak, my consumption is off the charts (literally, it goes beyond the scale of the energy graph).
     
  20. Khatsalano

    Khatsalano Member

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    Hey, have a good trip! We just did this and wrote it up here with pictures:

    Tesla West Coast Road Trip (2,000+ miles, 3 ferry rides, $0 in gas) Pictures

    Are you sure your vent louvers are not closed? They are sometimes very hard to visually identify because all-the-way left or right = closed, but they will still look open if you're used to a regular vent from any other car manufacturer. Separately, you can always book an appointment for service in Vancouver and explain you're on a road trip to see if they can fit you into the schedule. Good luck.

    - K
     

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