Re: Why it took a year: Well, no real problem, I guess, since I didn't strongly insist on immediate action. Some time roughly a year ago when I first complained of the buzzing, they indicated it was "normal." Then last January I asked again and they indicated they were aware of it, and they had a fix on the way. I got the impression in a month or two they would email me when the parts were in. Then when I didn't hear anything for half a year, I requested a service appointment for a few other items plus 2 year regular service. I asked again about the buzzing, and they indicated they just were receiving a shipment of DUs, and would include DU swap with the rest of the service appointment.
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Drive Unit Replacement Poll
- Thread starter nleggatt
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- Driving Dynamics Model S
When I brought mine in, they explained the procedure for this. They put a microphone on the drivetrain and record the sound. Then they send it to Fremont for analysis vs. the logs. Fremont decides the urgency. We all talk about "milling" and "balloon squeal", but without recordings for each, we do not know for sure that we are experiencing same symptoms. It is possible that some of the replacements are pre-failure (and therefore urgent), and some are "cosmetic", meaning no real risk... just an aggravating noise.
I personally LIKE that Tesla is taking a different approach on this. Recall is a blunt instrument for a world without telemetry. When you have a fleet of cars with sophisticated telemetry and internet connectivity, there's got to be a better way of doing proactive maintenance, and monitoring known issues. And, among their many innovations, Tesla is doing this. I think it is great.
mknox
Well-Known Member
Yes, that is how mine was diagnosed. My sense about the proactive replacements, however, was that these were cars identified by VIN, date of manufacture, or something like that. This is how I got on the list for battery contractor replacement. It wasn't due to any telemetry the car sent but, was based on a part they determined was defective. In fact, my contactors failed before Tesla had a chance to replace them and they told me that my car had not thrown any codes even though I saw a stream of error messages scroll across the dash.
I don't mind it, I just find it interesting. A component is determined to be systematically "sub-par" and they initiate "proactive replacements" instead of "recalls". I just got a "recall" on my other car since Toyota "determined" there was a problem with the passenger airbag. I don't think any less of them for calling it a "recall". I'm just glad it's getting fixed.
Tesla only seems to be able to diagnose active error alerts, not ones that have cleared.
Well, generally recalls are for safety defects or non-compliance w/FMVSS. Drive unit noise isn't either of those.
But, certain things, such as sudden loss of propulsion (aka stalling) is definitely recall class, since tens of millions of vehicles have been recalled for that. Now, if there were only some way to let an appropriate regulatory agency know when such things happen...
Sometimes, automakers will have a service campaign (sometimes preceded by the word "limited) on certain systems or extend the warranty on certain systems/parts. Examples: http://www.nissanassist.com/web/, Combination Meter Warranty Enhancement | PriusChat and LSC A0N - HV (Inverter) Water Pump; Dealer Letter and Technical Instructions | PriusChat But these aren't recalls.
mknox
Well-Known Member
That's exactly what happened when my contactors failed. There was a loud bang, a total loss of propulsion power and HVAC (it was 10 degrees F) right on the freeway on-ramp. I was on the "proactive replacement" list, but my failure happened before my number came up.
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I would have thought so, but was told there were no errors noted in my system when my contactors went. I had multiple "Pull Over Safely", "Contact Tesla Service", "12v Failure" etc. messages stream by at the time.
I wonder if there was something unique about this failure that prevented a log entry. At my last appointment, they were asking me about my touch screen error and what time it happened, so they could look for the time stamp in the logs. Maybe it varies, depending on the error.
mknox
Well-Known Member
When my contactors failed, I had no drive power and no heat (it was damn cold!) but my 12v systems were still working. I was on the phone with Tesla Service a number of times because I was looking at a 2-3 hour wait for a flatbed. Throughout this time, I had tried to get the car started by tapping the brake, trying the "Shutdown" option from the screen all to no avail. At about the 1.5 hour point, I tapped the brake again and got a series of clicks and bangs from under the car that I'd never heard before. Then the heat came back on. I put it in Drive and had traction power! Tesla suggested I try and make my way to the Service Center and so, driving as gingerly as I could, did just that. Other folks with contactor failures have reported the same behavior, but in some cases, the car fails again after a few minutes. I got lucky. Maybe the loss of all power "cleared" the messages? Or maybe when it came back to life, the errors got wiped?? Not sure, but they told me they saw no errors or fault codes.
mknox
Well-Known Member
Yes, I believe this is the sound that I call my "angry mosquito". Some say it sounds like a buzz saw way off in the distance. I think some may refer to it as a "milling" sound. To me, it sounds "electrical" and the work "milling" makes me think of a "mechanical" sound, but I believe we're all talking about the same thing. I am scheduled for a DU replacement as a result of this sound. I think it has to reach a certain decibel threshold before Tesla will act on it.
The sound mine was making was a low-level whirring that was relatively constant at speeds over about 65 mph. It would get slightly louder the faster you went, and would go away when you lifted off the accelerator.
It was almost like white noise--it's hard to describe it specifically. Grinding is sort of close, but it wasn't that aggressive. Milling is probably the best analogy I can think of.
It seemed to be getting gradually louder as time went on, but maybe that's just because I was becoming progressively more irritated by it.
It was almost like white noise--it's hard to describe it specifically. Grinding is sort of close, but it wasn't that aggressive. Milling is probably the best analogy I can think of.
It seemed to be getting gradually louder as time went on, but maybe that's just because I was becoming progressively more irritated by it.
I think the clarification of the sounds is indeed useful... particularly given that I'm hearing a new noise.
I previously had reported a whine with my drive unit, which was subsequently replaced. In retrospect I'd qualify it as a "mechanical whine", which probably corresponds to the "milling" sound folks have taken to calling it here. It was tied to drive line rotational speed, not power delivery. This appears to be the bearing issue Tesla acknowledged some time back
I now have an "electrical whine" that's manifested itself. It's tied to power delivery, not drive line RPM. It is a nigh-pitched frequency as I can often hear with other electrical devices. I'd suspect intverter/power electronics...
I previously had reported a whine with my drive unit, which was subsequently replaced. In retrospect I'd qualify it as a "mechanical whine", which probably corresponds to the "milling" sound folks have taken to calling it here. It was tied to drive line rotational speed, not power delivery. This appears to be the bearing issue Tesla acknowledged some time back
I now have an "electrical whine" that's manifested itself. It's tied to power delivery, not drive line RPM. It is a nigh-pitched frequency as I can often hear with other electrical devices. I'd suspect intverter/power electronics...
mknox
Well-Known Member
Yes, that's what I have now, and suspect the same thing. My first drive unit (replaced) had a very loud low frequency hum very reminiscent of a large power transformer. It would come on immediately under power or re-gen, but if I adjusted the accelerator such that the power meter was at zero, it would stop. I could turn the hum on or off like a switch by doing this.
All three of my DU replacements were for the high speed hum above 60 MPH. In addition to that, the last DU that was replaced also had the electrical "mosquito noise" issue. I'm 11,000 miles into my factory-fresh DU that was installed in February, and knock wood, no issues.
It sure seems like Tesla should've issued a recall for those on their "proactive replacement" list instead of what they did. As I've pointed out in ahem... the other thread, it seems like what Tesla's doing could potentially be illegal under US law. If more people actually experiencing loss of propulsion actually reported the safety defect to NHTSA...
Kinda on this note, I learned of some VW eGolfs suddenly shutting down, some losing propulsion while in motion via EGolf or LEAF - Page 2 - My Nissan Leaf Forum. I skimmed Volkswagen e-Golf Forum View topic - Dangerous E-Golf Shut Downs and the threads it linked to, as with normal car forums, there's no bashing people about reporting to NHTSA, claiming it's not a safety issue, downplaying it, "it's random" so therefore don't report it, trying to convince people not to report to NHTSA, etc. BS.
Drive unit is a sealed device. Rather than have it locally serviced, Tesla opts to do repairs centrally. So when a unit requires service - by analogy, anything from timing chain adjustment to head gasket to valve job - they have it sent to Fremont and replace with a refurbished unit. This promotes quality by giving R&D direct insight into service requirements so they can continuously improve. They are also erring on the side of replacing even for cosmetic issues that don't portend failure. At some point, I predict they will do more of this at service centers, but also many of these cosmetic and failure issues will be sorted as product design evolves. Some are here stewing, interpreting each drivetrain repair as major issue. They're not. Tho some are. It's annoying for those who have had a failure or multiple repairs, but that seems a small %. We are now into the second billion miles, so Tesla's approach is sure keeping the cars on the road!
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