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Powertrain fault 972

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

  1. Doug_G

    Doug_G Lead Moderator

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    That does seem pretty long. Tesla service here takes "off road" vehicles very seriously, and they pretty much pull out all the stops to get them running again.
     
  2. dhrivnak

    dhrivnak Active Member

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    I agree two weeks is a long time but I am 350 miles away from Atlanta, the newest service center. Apparently there are two of them and one is California for a week for training. So a trip up and fixing it is about two days for them. While frustrating I try to put myself in their shoes as they are a new company trying to grow. At least they have gotten back to me in a timely manner.
     
  3. dhrivnak

    dhrivnak Active Member

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    Well I have to hand it to the Rangers. They were superb in finding the root cause of the problem we hope. Apparently some pins, or rather plugs on the large connector to the PEM were not holding the pins securely, creating a partial connection. With slightly more resistance the two accelerator circuits would not agree and thus the fault was thrown. The increased the tension and the car is running well. I got to help remove the PEM and since it was out they did a thorough cleaning. It did not need it as my PEM was quite clean; but now I feel confident in doing it myself. Or I should say with a helper as with the PEM in a 1.5 weighing about 140 lbs and it is a bit much for one person. They also confirmed that tests are underway for a new motor/PEM upgrade that would significantly improve performance. That would be cool if it comes to pass.
     
  4. hcsharp

    hcsharp Active Member

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    Wow. That had to be hard to find!

    I was told by a Ranger that when you disconnect power from the PEM it automatically shuts off the battery contactor and can't be re-connected without their service computer. If you posted pics with instructions that would be REALLY nice of you! I never would have guessed that thing weighed 140 lbs. A lot of times they do it alone!
     
  5. dhrivnak

    dhrivnak Active Member

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    I am quite sure they did not use a service computer to "turn the car on". But I am 99% sure he turned off the power through the VDS and then reenabled it. That part I forgot to keep a close tab on as I was in the back helping remove the PEM. PEM_Cleaning_03.JPG

    I feel confident I can get the PEM out and cleaned but will need some help or poking around to find out how to deactivate the system. The prior ranger just lifted the PEM slightly and blew it out. And that range pulled the safety disconnect first. That way the radio looses it's brains. After seeing the full removeal that is the better way to go for a cleaning in IMHO.

    Here is a shot of the motor. PEM_Cleaning_12.JPG
     
  6. hcsharp

    hcsharp Active Member

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    Dave thanks for the pics. The 2.5 PEM is quite different. I'm hoping it's the same as far as not needing their computer to re-enable it. Which mounting bolts did you have to remove?
     
  7. dhrivnak

    dhrivnak Active Member

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    The bolts are a bit of a challenge. There are two from the underside you need a 2' extension and to remove the bottom pan that covers the rear of the car to reach. Then there are two, one on each side, that connects to the battery and on the drivers side there is a grounding strap to the battery pack just infront of the attachement bolt. Then there are 8 connections I do believe to the PEM, 6 of them are from the underside and not particularly easy to reach, but not impossible either.
     
  8. hcsharp

    hcsharp Active Member

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    Has anybody seen this warning on the VDS?

    DMC: Wear Factor Warning
    ID: 1153

    It's a debug-only warning so you won't get this unless your car is in debug mode (which I requested).
    What is the DMC?
     
  9. PRJIM

    PRJIM Member

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    DMC is present on most every fault when in debug mode. A few days ago I got the dreaded DMC-ABS defective fault which supposedly disabled Regen. DMC is just the nomenclature Tesla uses for Diagnostic mode. It is present on almost all of the errors when in debug mode. I am sure you know how to take it out of debug mode, if not feel free to PM me and I will send you the codes.
     
  10. hcsharp

    hcsharp Active Member

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    OK here's the official response from Tesla:
     
  11. dhrivnak

    dhrivnak Active Member

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    Well the power train fault 952 came back a few more times. This time Tesla replaced the PEM and the rear wiring harness which is no small task as there is about 30 connectors. My hats off to my Ranger team as they did an exceptional job putting in a very long 13 hour day of mostly frustrating work. The main issue was Tesla used a 9 pin connector (but just 2 wires) to see if the charge port door is closed. My old wiring harness used pins 2 and 8. The new wiring harness used pins 4 & 5. So until we discovered the connector change the car thought the charge port was open so it would not start.

    Hours were spent tracing the new wiring harness, trying to upgrade the firmware and even putting in my old PEM. We spliced in my old connector to the new wiring harness.

    What dedication and I hope we do not burn out the Rangers. I had a nice stress free drive today feeling that the fault has been corrected once and for all.
     

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