P85D Front Motor Died

[Woland]

I'm the OP on this thread, and I just got an update from Tesla service. It turns out that the failure was in the rear drive unit's sensor, and that the car reacted by shutting down the front drive unit.

Tesla said they are replacing the rear drive unit with a used, remanufactured unit as that is Tesla policy, even at the low mileage (3,500 miles) on my car. I bought a brand new car, it failed (pretty catastrophically, I think it's safe to say) under completely normal, mild driving conditions, at no fault of my own, and now I have to accept a rear drive unit (arguably the most important piece of equipment in the car) that has more miles on it than my original?

With this situation, my opinion of the quality of the car and the company has plummeted. The P85D has only been on the market for 7 months or so, and after 3,500 miles it fails, and to make things right, Tesla fits my car with a critical part that is older / has more miles and wear-and-tear on it than what I brought to them to service, essentially lowering my car's value, and reducing the potential time until the next failure. I've lost confidence in my car, the company who sold it to me (and who services it), and now I will likely dread the next several months / years of ownership, as I'll always wonder what failure awaits me next, and how it will be resolved by Tesla.

I've escalated the issue to the service manager and hope to hear some better news.

 

[Tdriver]

Lets look at this from a more positive viewpoint.....do you know for a fact that the replacement is older, has more miles on it, and more wear and tear? Will you not have the same warranty that you had before the incident? Will you not have the same performance capability as before the incident? I can understand that mentally it can be a worry but I don't think you will have less of a car. Anyway, hope things turn out for the best for you.

 

[jerjozwik]

it has been rebuilt. therfore not used. sure the housing might have "miles" on it but all the internals are new.

 

[WarpedOne]

and reducing the potential time until the next failure.

Actually, no.
Law of big numbers says that units that failed soon and were repaired will last longer than those which did not fail soon.
You now have a better car than new. Try to wrap your mind around it.

 

[strider]

Actually, no.
Law of big numbers says that units that failed soon and were repaired will last longer than those which did not fail soon.
You now have a better car than new. Try to wrap your mind around it.

+1 in the electronics world, most failures are at the very beginning on the component's life. So once it's been running for awhile the odds of it failing go down (this is the exact opposite of mechanical devices). Further, you still have your 8-year unlimited mile warranty which covers the drive unit. And finally, your idea that your resale value has gone down is complete speculation on your part. A factory part is a factory part for resale purposes. The announcement of the ludicrous P90D has decreased your resale far more than a reman drive unit. Welcome to the world of Tesla, where cars depreciate like TV, computers, and phones.

 

[brianman]

And finally, your idea that your resale value has gone down is complete speculation on your part. A factory part is a factory part for resale purposes.

That's a good point. Despite the CPO program being active for a month or more, I haven't noticed any threads asking questions like "I'm looking at this CPO but it's on its 2nd drive unit, should I be worried?" This suggests that drive unit replacements haven't been part of the purchase discussion for CPO buyers on TMC.

 

[WarpedOne]

Welcome to the world of Tesla, where cars depreciate like TV, computers, and phones.

Hey, that's NOT a happy thought!
But it also is not exactly true. Due to tesla's CPO program, used tesla's hold value pretty good, better than most other cars.

TV's, computers, phones depreciate like stones falling into a black hole.

 

[Woland]

I spoke with the service manager and they have ordered a new rear drive unit, and the car will likely be returned to me on Monday. This unit is supposedly what's being put into cars currently on the assembly line, and some form of update was done to those since my car was assembled.

My concern with remanufactured rear drive units (as opposed to the fronts) is that this is the same drive unit that's been around for ~3 years, so it is not clear how "used" any part of it is, and the service folks could not say with any certainty that the issue that caused my failure was specifically addressed in these remanufactured units.

Personally, and perhaps others might argue this, I don't like the idea of paying $135,000 for a new car and having it fail within 3,500 miles, only to have the failing component replaced with something that is potentially 3 years older than what I bought. Some have suggested that the older parts might even be better than new, but I'd claim that's a general assumption as well, and in general "new" is easier on my mind after an incident like this.

I also asked the service manager if this failure may have had any negative impact on my front drive unit (as there was considerable "stuttering" just prior to the failure), and he explained that this was simply the sensor cutting power to the front unit, and not a harmful situation, so they are not concerned about its health at present.

I'm grateful to the service center for working to satisfy my request, and I'll reply here again after I've had a chance to drive the car again. Still, this experience has weakened my confidence in the car, and I'll be driving around for a long while worried about what's next.

Thanks for everyone's comments and insight!

Edited to add this: I should clarify that I understand the idea that if a remanufactured unit was rebuilt to specifically address issues that improve the unit above and beyond a new unit, great, that would give greater peace of mind. But I've had no such assurance from Tesla that is the case, but they did state that the rear drive unit that they ordered was the "latest" and "updated," and the insinuation was that it was thus better than a rebuilt unit. I'd imagine if there were any known issues, the units they're putting into new cars now would be the best possible "version" available as of today. I hope that's the case.

 

[brianman]

@Woland
If it's any consolation, we could meet up for dinner sometime and talk about repairs on both my vehicles. Some stories are best not posted. PM me if interested.

 

[AmpedRealtor]

I spoke with the service manager and they have ordered a new rear drive unit, and the car will likely be returned to me on Monday. This unit is supposedly what's being put into cars currently on the assembly line, and some form of update was done to those since my car was assembled.

My concern with remanufactured rear drive units (as opposed to the fronts) is that this is the same drive unit that's been around for ~3 years, so it is not clear how "used" any part of it is, and the service folks could not say with any certainty that the issue that caused my failure was specifically addressed in these remanufactured units.

Personally, and perhaps others might argue this, I don't like the idea of paying $135,000 for a new car and having it fail within 3,500 miles, only to have the failing component replaced with something that is potentially 3 years older than what I bought. Some have suggested that the older parts might even be better than new, but I'd claim that's a general assumption as well, and in general "new" is easier on my mind after an incident like this.

I also asked the service manager if this failure may have had any negative impact on my front drive unit (as there was considerable "stuttering" just prior to the failure), and he explained that this was simply the sensor cutting power to the front unit, and not a harmful situation, so they are not concerned about its health at present.

I'm grateful to the service center for working to satisfy my request, and I'll reply here again after I've had a chance to drive the car again. Still, this experience has weakened my confidence in the car, and I'll be driving around for a long while worried about what's next.

Thanks for everyone's comments and insight!

Edited to add this: I should clarify that I understand the idea that if a remanufactured unit was rebuilt to specifically address issues that improve the unit above and beyond a new unit, great, that would give greater peace of mind. But I've had no such assurance from Tesla that is the case, but they did state that the rear drive unit that they ordered was the "latest" and "updated," and the insinuation was that it was thus better than a rebuilt unit. I'd imagine if there were any known issues, the units they're putting into new cars now would be the best possible "version" available as of today. I hope that's the case.

Good for you for asking for a factory fresh drive unit. I did the same thing and received a factory fresh unit back in February. I wouldn't have if I didn't specifically ask for it.

You dodged a bullet, to be honest with you. I've had two remanufactured units replaced, as have thousands of others. Most of the remanufactured units are still suffering from problems, so they obviously are not being remanufactured to the current manufacturing specifications.

 

[Andyw2100]

There's a lot of discussion in this thread about the dual motor cars not really being able to operate with either motor going down. I certainly believe what I've read in this thread. I fear Mr. Musk may have been "exaggerating" again in the following video. Watch at about the 20 second point, as he discusses how the dual motor cars are like twin-engine planes, etc.

 

[wk057]

There's a lot of discussion in this thread about the dual motor cars not really being able to operate with either motor going down. I certainly believe what I've read in this thread. I fear Mr. Musk may have been "exaggerating" again in the following video. Watch at about the 20 second point, as he discusses how the dual motor cars are like twin-engine planes, etc.

Interestingly in this video he specifically says you can drive on the front or the rear. I'm not sure how that's possible with a rear inverter failure. The accelerator pedal is definitely connected only to the rear drive unit (double checked this on the schematic) and appears to be analog with two variable resistors (presumably for redundancy) both run to the rear drive unit.

So I'd be very surprised if the car could survive a rear motor failure and become front wheel drive temporarily.

*sigh* I'll just add this to the list of over-promises.

 

[Andyw2100]

Interestingly in this video he specifically says you can drive on the front or the rear. I'm not sure how that's possible with a rear inverter failure. The accelerator pedal is definitely connected only to the rear drive unit (double checked this on the schematic) and appears to be analog with two variable resistors (presumably for redundancy) both run to the rear drive unit.

So I'd be very surprised if the car could survive a rear motor failure and become front wheel drive temporarily.

*sigh* I'll just add this to the list of over-promises.

Yes, it was based on what you and others had written in this thread, and on having heard Musk make that statement that I wrote that I feared he may have been "exaggerating" again. (I remembered, roughly, that he had made statements of that nature in this video, so went looking for it to confirm what I recalled.)

 

[Woland]

Here is my promised follow-up after picking up my car after having the rear drive unit replaced. As I mentioned, they put in a new drive unit and the issue is gone (for now) and the car drives nicely.

I appreciate my service center agreeing to put in a new (versus remanufactured) drive unit, but as with any service appointment, you risk damage to your car while it's out of your possession, and that was sadly the case for me. A very quick inspection of the car revealed a pretty bad ding (with a missing chunk of plastic and paint) and long scratches on the car. My service center said they'd take care of me and fix and repaint it, but I haven't heard back from them yet on that.

I also noticed circular, swirling scratches all over the car from when they washed it. On top of that, there are a few fuzzy bunches of nylon (or some other material) lint stuck in a few gaps of the body and I've still not been able to get them out without scratching the car. I can't believe they would use such a material to wash my car.

I really hope I don't need service again soon.

 

[JER]

Remember that the drive units contain multiple systems.

Failure of a rear drive unit for mechanical or power electronics reasons might allow you to continue on the front drive unit. There was a thread (which I can't currently find) where someone claimed this had happened.

A failure that shuts down the motor controller (which is in the rear unit) will disable both drive units; it commands both of them.

 

[Throtex]

Hey folks. Just picked up my S-P90DL about a week ago (April 7), and last night I got the dreaded "front motor disabled" as I was accelerating from a light (at around 175 miles on the odo ... new record?). It wasn't terribly dramatic, just a bit of wheel spin as AWD went away. The car ran fine on just the rear motor, and I even parked it then drove away again like that. I didn't have any other error messages at the time.

This morning, I get in the car expecting the worst, and was not surprised. Same issues others report, including a service warning, 12V battery issue, etc. Then it says the car cannot start. Then the whole stack shuts down and the car goes offline. Called Tesla service and they suggested just calling roadside assistance. They're sending a flatbed shortly to drag the car out of the garage.

I'll update with whatever the issue is. Not surprised or even upset, since I figured this would be more of an Italian sports car ownership experience than a Honda ownership experience. I just wanted to drive the damned thing over the weekend! But the folks I've talked to are very professional and reassuring, and I'm sure they'll get the car up and running in no time. I'm honestly mostly curious from a technical perspective (as an electrical engineer) to know what went wrong!

I suppose my bigger concern is what will happen with the Model 3 release. I'm not sure Tesla is ready for issues on that kind of scale. I hope they figure it out though, because the car is an absolute thrill to drive (or be driven by).

 

[Andyw2100]

Hey folks. Just picked up my S-P90DL about a week ago (April 7), and last night I got the dreaded "front motor disabled" as I was accelerating from a light (at around 175 miles on the odo ... new record?). It wasn't terribly dramatic, just a bit of wheel spin as AWD went away. The car ran fine on just the rear motor, and I even parked it then drove away again like that. I didn't have any other error messages at the time.

This morning, I get in the car expecting the worst, and was not surprised. Same issues others report, including a service warning, 12V battery issue, etc. Then it says the car cannot start. Then the whole stack shuts down and the car goes offline. Called Tesla service and they suggested just calling roadside assistance. They're sending a flatbed shortly to drag the car out of the garage.

I'll update with whatever the issue is. Not surprised or even upset, since I figured this would be more of an Italian sports car ownership experience than a Honda ownership experience. I just wanted to drive the damned thing over the weekend! But the folks I've talked to are very professional and reassuring, and I'm sure they'll get the car up and running in no time. I'm honestly mostly curious from a technical perspective (as an electrical engineer) to know what went wrong!

I suppose my bigger concern is what will happen with the Model 3 release. I'm not sure Tesla is ready for issues on that kind of scale. I hope they figure it out though, because the car is an absolute thrill to drive (or be driven by).

Welcome to the forums. It sounds like you have a great attitude, considering your experience thus far.

One thing to be aware of, and possibly take issue with if it comes up...

In theory, if you do need to have your drive unit replaced, I believe the Tesla warranty would allow for it to be replaced with a rebuilt / remanufactured / (perhaps some-other-term, but you get the idea) drive unit. If my car had this happen to it so soon after delivery, and if Tesla tried to give me anything other than a brand new drive unit, I would definitely try to make the argument that the drive unit should be replaced with a brand-spanking new one.

Anyway...just something to be aware of.

Good luck!

 

[DDotJ]

Sorry about the luck you seem to be having with Service and Drive Units. I had no idea that remanufactured and refurbished drive units were not up to spec. I went in for the dreaded milling noise on my drive unit and they replaced with a Revision Q drive unit. I have no idea whether it was a new or refurbished unit, but it's been great so far and the car is a pleasure to drive around again.

From what it looks like just based on the forums, Tesla's DU reliability has definitely gotten better. There are only a handful of drive unit failure posts nowadays and most of the premature wear and odd noises seem to have been figured out. It sucks that you had a failure so early on but I'm sure the next DU you receive will be a more reliable unit, this one is probably just a bad apple.

 

[deonb]

he discusses how the dual motor cars are like twin-engine planes, etc.

Not the best thing to pick for a comparison...

It's a general saying in aviation circles that the only thing the second engine is good for is to fly you to the scene of the crash.

 

[Andyw2100]

I had no idea that remanufactured and refurbished drive units were not up to spec.

I hope you didn't infer from my post above that I was suggesting that remanufactured and refurbished drive units were not up to spec. I was merely suggesting that if I had just purchased a brand new Model S, and had a drive unit failure with under 200 miles on the drive unit, if the drive unit needed to be replaced I'd want it replaced with a brand new drive unit. That's not suggesting non-new units aren't up to spec. It's just suggesting non-new units aren't, well, --NEW--!