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Drive Unit Failure after Road Trip

Discussion in 'Model S' started by nchristopher, Sep 2, 2017.

  1. nchristopher

    nchristopher Member

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    Location:
    nyc
    Had my first road trip in my model S (2015 P85D). Drove from NYC to Nashville and back to see the eclipse. The drive was great for the most part. Had some extra stops due to range anxiety. Used a blink charging station for the first time. Tried to use an extension cord to charge once which failed miserably. Ran down the battery to stated range of 6 miles once. Drove over 2000 miles in about 6 days.

    However, the main issue started on the return trip. The car started giving a warning "Car May Not Restart". Looked this up and though it could be 12V battery or DCDC charger problem. However, it gave this warning for 2 days in a row without any changes in driving or charging. Continued to use superchargers and trip was uneventful.

    The day after returning home, I brought the car to Tesla Service. As I parked the car in the lot, the PRND letters turned red. As if the car knew it was time to give up the ghost. Tesla looked over the car and declared that I needed a new drive unit. Fair enough. Not terribly worried. I had thought my drive unit made a little noise but never was worried about it.

    I got the car back 2 days ago and its driving fine. Slightly quieter than before. However, it seems like my wh/mi has gotten worse. My regular commute with AC on would previously net me about 350 (and it was hotter). Now, with the AC off I am getting about the same wh/mi.

    Should I be worried? I have not notified my SC yet. Want to get more data.
     
  2. BrokerDon

    BrokerDon Member

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    How many miles on your odometer when this occurred?

    Which drive unit did Tesla replace? (front or rear)

    Just curious since I also have a 2015 P85D that's running great... although the front drive unit does make a little whining noise which Tesla SC said was normal. I think the front drive unit is just whining because the back drive unit is so much larger. Unit size envy is real. LOL
     
  3. cwerdna

    cwerdna Active Member

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    Out of curiosity, when was your car built?
     
  4. nchristopher

    nchristopher Member

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    April 2015 build. Car had just over 20k miles.

    My front drive unit is also whining. They replaced the rear
     
    • Informative x 1
  5. BrokerDon

    BrokerDon Member

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    Not sure if you were asking me or nchristophoer. Our 2015 P85D was built in March 2015... and we took delivery in late July 2015
     
    • Informative x 1
  6. kort677

    kort677 Active Member

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    I am glad that you were able to make it home without any problems on the road but next time you ar anyone else sees a warning like that pop up call it in to tesla immediately because as you saw it could render the car inoperable at anytime without notice.
     
  7. ItsNotAboutTheMoney

    ItsNotAboutTheMoney Well-Known Member

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    Yes, you should be worried. You should be worried that your tire pressures are too low.
     
  8. Maxv

    Maxv Member

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    Location:
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    Depending on where you're reading that figure, it may refer to drive unit energy consumption only and neglect accessory consumption. And thus the numbers should be the same.
     
  9. mkjayakumar

    mkjayakumar Active Member

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    350 wh/mile is high even with AC on. You should get less than 300 atleast on the highways.
     
    • Like x 1
  10. kort677

    kort677 Active Member

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    At what speeds?
     
  11. mkjayakumar

    mkjayakumar Active Member

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    I get between 275 to 290 wh/mile or less consistently between 65 to 70mph on my S85
     
  12. bktiger86

    bktiger86 Member

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    I think his is P that is why it is taking more. I drove the P100D X and 100D X the P itself took around 350wh/mi very conservatively.
     
  13. nchristopher

    nchristopher Member

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    Forgot to mention my commute is mostly within NYC. About 5 miles of highway and the rest is stop and go.

    I have corrected the tire pressures. Thanks
     
  14. mkjayakumar

    mkjayakumar Active Member

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    Ha.. no wonder you are at 350 wh/mile.
     
  15. nchristopher

    nchristopher Member

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    I did call tesla and their response was to be prepared to stop at any time. They said I could stop and go to the nearest SC but it wasn't really an option with full car and nowhere to stay plus needing to be back at work. Thankfully the worst case of needing a tow did not happen.
     
  16. nchristopher

    nchristopher Member

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    Yes. I assumed that NYC was the cause of my baseline WH/MI being high. The main concern I have now is that the new drive unit (which should be more efficient with less milling - less friction) is seemingly less efficient.
     
  17. GTIceman

    GTIceman Member

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    I am constantly over 300 in my P90DL and I'm not mashing the pedal. On highway I can get 280. Tire pressure is 40 cold. She is a 2015 build V1 pack.

    Lucky that the OP made it back before the death of the unit.
     
  18. Skotty

    Skotty 2014 Model S P85

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    I have a 2014 P85, and tend to get between 290 and 325 on good days, and that can go up to over 400 in the winter.
     

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