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Powertrain fault 972

Discussion in 'Roadster: Technical' started by dhrivnak, Sep 25, 2012.

  1. dhrivnak

    dhrivnak Active Member

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    #1 dhrivnak, Sep 25, 2012
    Last edited: Sep 25, 2012
    Sorry the title should have read Roadster Dead, Powertrain fault 972

    Has anyone heard of a power train fault 972? The roadster had been running great and took it to a car show Saturday and Plug_In day Sunday. But today after I charged in range mode to head out on a 500 mile road trip to the EVCCON (Electric Vehicle Conversion Convention) I got the fault. The car died about 12 times. I can restart but then can only drive from 200 yards to 1/2 mile when it faults and dies again.

    Just uploaded the logs to Tesla but they are not giving much hope of an easy fix.
     
  2. dhrivnak

    dhrivnak Active Member

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    It appears to be an accelerator pedal error. Tesla suggested a tighten a ground and it seems to be working. Actually they suggested sending a ranger but being 400 from tbe nearest center is not quick or easy.
     
  3. Doug_G

    Doug_G Lead Moderator

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    Okay that is reassuring. It detected the fault and prevented a potentially unsafe condition.

    FYI, the pedal has two potentiometers, one goes up in resistance when you press the pedal, and the other down. If they don't both translate to the same requested speed then it causes an error. It's a very safe system.
     
  4. dhrivnak

    dhrivnak Active Member

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    #4 dhrivnak, Sep 25, 2012
    Last edited: Sep 25, 2012
    Not really in my opinion as when it faults the motor shuts off. I got stuck in the middle of an intersection. Fortunately there was no traffic. But so far so good as I am 200 miles into my trip and charging for the night.

    I must give credit to Tesla for jumping on the logs and pointing me to tbe ground. The ground couriously enough is under the hood passinger side below the fat orange wires. I had to remove a shroud which was easy to reach the 13mm bolt. Will try to post picture when i return
     
  5. hcsharp

    hcsharp Active Member

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    Glad it didn't end your trip. Can you give us more info on how you fixed it? Where was the loose ground connection?
     
  6. dhrivnak

    dhrivnak Active Member

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    Wow i am quite impressed with Tesla's service. They called and texted me to see if all is OK. Fortunately it is and I have gone 310 miles and am charging at KFC where they have 3 level 2 chargers. Now for tbe last 190 miles.
     
  7. NigelM

    NigelM Recovering Member

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    Good to hear it was something simple and that you're on the road.

    When you get back, think about writing up a short post on your service experience over here: Actual-Service-Experiences-with-Tesla
     
  8. Jaff

    Jaff Active Member

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    I think Doug was referring to "safe" as in safe from runaway type events i.e. uncontrolled acceleration.
     
  9. Adm

    Adm Active Member

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    Maybe a better reaction of the car should be to limit power to a minimum so you can clear an intersection of get to a safe place when on a highway or freeway.
     
  10. Doug_G

    Doug_G Lead Moderator

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    I really don't think so. The car must be designed, and is designed, to prevent any possibility of runaway throttle. I'd far rather have the car stall out on me at a bad time than take any risk of the throttle being stuck at even partial power.

    Years ago in an old gasser I experienced a stuck throttle at freeway speeds and in fairly heavy traffic. In the time it took me to figure out what was happening and do something about it the car accelerated quite a bit. Luckily I spotted an empty off-ramp and dodged over to it through a hole in the traffic. It could easily have caused a serious accident.

    Now imagine doing that in a Roadster. Yikes!!! I'll take a stalled car any day!
     
  11. wycolo

    wycolo Active Member

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    #11 wycolo, Oct 1, 2012
    Last edited: Oct 1, 2012
    > stuck throttle [Doug_G]

    One of those crap Audis??

    > 13mm [dhrivnak]

    Ok, add 13mm combo wrench to toolkit.

    > The ground couriously enough is under the hood passenger side below the fat orange wires. [dhrivnak]

    Must be the trunk hood since there are no fat orange (400vdc) wires up front. Takes me back to the Rust Belt (Northern NY State) where if anything weird electrical happens you first dismember the ground connections, grind them bright, reattach & paint over.
    --
     
  12. W.Petefish

    W.Petefish Active Member

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    No. It is under the front hood. Under a shroud on the passenger side. (assuming NA cars, others may differ.)
     
  13. wycolo

    wycolo Active Member

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    > It is under the front hood. Under a shroud on the passenger side. [W.Petefish]

    Yes, there it is. Mine is covered with electrical putty of a brown/grey color. Hard to see before sunup. [Drill hole in shroud, insert 13mm socket on wobble extension. Tighten. Insert hole plug.] Finally, a reason to open the front hood. Been left for dead once already:wink:.
    --
     
  14. Doug_G

    Doug_G Lead Moderator

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    No, it was an early 80's vintage Honda Accord. The vanes in the carburetor stuck open. This is not something you want to experience!
     
  15. vfx

    vfx Well-Known Member

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    There's charging at KFC?!
     
  16. dhrivnak

    dhrivnak Active Member

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    Yes there is charging at the KFC in Mt. Pleasant TN. Three of them actually and they work after hours, thank goodness.

    As to the powertrain error I did a few more faults last week so Tesla plans to send a ranger and I am fine with that. They are in a much better postion to fix than I am. And yes at least on a 1.5 there are orange wires under the hood. And because the nut is burried a bit you cannot reach it with a 13mm wrench. You really need a 13 mm socket with 3" extension. Hrivnak_Ground.JPG
     
  17. driver_EV

    driver_EV Member

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    Wow, a bit scary there. Glad it ended up being a safe resolution to the "sudden dead car" event.

    I must say a limp mode of some sort is called for. Standard creep/crawl at least, with possibly a slight pulse of "double crawl" speed depending on how the throttle is failing.

    I'm sure they will sort out the fault for you.
    -Richard
     
  18. dhrivnak

    dhrivnak Active Member

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    I have to hand it to Tesla service. While I thought I had the problem licked they wanted to send out a ranger to be sure. As it turns out if one removes the 13mm bolt and the wires attached to the ground point. There is another nut that holds the stud tight. It turns out this lower "hidden" nut was a little loose. The bottom bolt was tightened and wires reattached and all appears well. Additionally to be on the safe side they replaced the accelerator pedal. Both the ranger and I are 99% the ground is the issue but with me 400 miles from a service center it is better to be safe than sorry, especially since it is covered under warranty.
     
  19. dhrivnak

    dhrivnak Active Member

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    Unfortunately the fault has returned with a vengence. So the car is parked until Ranger Keith can make it back out my way in two weeks.
     
  20. hcsharp

    hcsharp Active Member

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    I'm sorry Dave. Two weeks??? That is too long to wait when you're car is not running! Tesla was way too slow to ramp up new employees for the MS roll out. Now Roadster owners in some areas are not getting the service that we used to.
     

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