Update: P85D Owner Advised By Tesla To Avoid Range Mode To Prevent Slight Power Loss


Tesla Model S P85D

Tesla Model S P85D

In order to prevent sudden slight power loss, Tesla is advising some P85D owners to avoid using range mode until a more permanent fix is available.

Here’s the backstory.  Several dual-motor Model S owners with the most recent firmware 6.1, (with update .167) are experiencing sudden power/torque loss while driving at speed.  The power loss is intermittent and unpredictable, happening at low speeds on up to highway cruising speeds.

UPDATE:  A Tesla spokeswoman let InsideEVs in on the straight scoop on what was happening with the P85D power loss situation – specifically that Tesla is dealing with incidents on a case-by-case basis:

“A small number of dual motor vehicles have experienced reduced torque in a single motor. In each one of the very few cases, vehicle systems remained fully powered and the car continued to be drivable. Tesla is not advising customers to turn off range mode. We are assessing each case to determine the root cause and are working directly with affected customers while we diagnose their vehicle. “

Power loss may leave you in a sticky situation, but what’s worse is that the vehicle’s regenerative brakes cut out when the power loss is experienced, meaning that some vehicles actually feel as though they speed up (until the brake pedal is depressed or power is regained) when the power loss issue kicks in.

This is a serious problem and Tesla acknowledges that it’s an issue.  Again, this only applies to dual-motor Model S EVs with firmware version 6.1 (with update .167).  Tesla’s engineering team, having been alerted to this issue.

Update: Model S owners who were experiencing this problem state that the sudden power loss issue never pops up as long as range mode isn’t selected.  Of course, this is only a temporary fix.  Tesla will have to address this with a software patch of some sort, but be advised that for the time being, if you own an 85D or P85D with update .167, we suggest you avoid range mode at all times.

Tesla claims that the affected vehicles are safe to drive until the more permanent fix gets pushed through, but we all know there’s nothing safe about losing power out on the open road. Even Ford reluctantly admitted that it’s issue with power loss wasn’t safe.

Let’s hope a permanent fix is in place within a few days, or else that dreaded R word might start getting tossed around.

Source: Tesla Motors Club Forum via Tesla Owners + Enthusiasts, story updated with statement from Tesla (Feb 26th 10:15am)

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87 Comments on "Update: P85D Owner Advised By Tesla To Avoid Range Mode To Prevent Slight Power Loss"

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Sounds like:

1. It’s a classic OTA fix.
2. They already have it figured out somewhat.

Yep. Just like the 50 cent shim fix for the drivetrains, yet fly 1100 drivetrains to Norway for emergency fix.

Step 1 – issue OTA update to disable range mode
Step 2 – fix the software

That was my first thought also.

It may even be possible to down grade to prior version of software, provided it doesn’t contain the related bug.

Either the problem must be fully investigated and confirmed by engineering before a fix and releasing an upgrade, or a downgrade is pushed over-air.

On the bright side a fix will be deployed within days thus minimizing the time effected vehicles are using the software with the bug. Without over air updates the bug could live on for month, or longer … vs. days. The best part is Tesla can view status of effected vehicles and can confirm that all effected vehicles have been upgraded.

The big question is: Did the owners agree to the software update? If so, it is their fault!

The difference between Tesla and Ford is Tesla will fix the problem by sending a software update to the cars, just as it has sent several previous builds of 6.1 already. All of the cars can be fixed the same day that way, at no inconvenience to the owners. No “recall” necessary. In less time than it takes a traditional automaker to mail recall letters, Tesla will have already updated all the affected cars.

@Ed +1

The other difference is the Focus Electric problem was more often than not a physical problem involving cabling or connections, which can’t be fixed in software. Intermittent connections made it harder to diagnose, there are many cases where owners had to wait weeks for the dealer and Ford to figure it out.

Interesting to note 4 more Focus Electric lemon buy backs recently showed up on eBay.

The Model X Beta Drivertrain software continues to evolve, I see. Should be near perfect by the time the vehicle is released to the public.

I like the way you think. Matches my hopes.

This stuff doesn’t help build my confidence in Tesla. They better get all these bugs worked out by the time the Model 3 arrives. This is a serious bug.

You have any idea how many lines of code it takes to make a Model S run? Ask any programmer, and they’ll tell you that perfection takes time. And software perfection– is almost never accomplished. It’s all about squashing the higher priority issues, like this, when they crop up.

Nature basically does a similar thing, using molecules of matter to code instructions in every cell of your body. Is Nature “perfect”? Well, it’s perfect enough to create sentient life; but it also allows disease and eventual cell death to occur. Does that diminish the “quality” of Nature to code for a planet full of fantastic life forms? Not at all. Same with Tesla.

The truly innovative thing about Tesla’s computer on their car, is it’s designed from the ground up, to be easily updated. That’s something it’s got over Nature’s way of evolving something over time. And other automakers are finally starting to see that for themselves, too.

Rationalize it to yourself however you want, but to me this is not a good thing. I think they need to test things more before rushing them out, then trying to fix them on the fly.

Again, you don’t “get” how complex the Model S is, at the code level… I can name a transportation product that has been out on the market for many years, that had serious bugs that caused human injury. Bugs that didn’t show up in 10 plus years of development work before it was released, or even years of firmware updates that occurred after the product was out in the wild. This is a company that took GREAT pains to make their software stable and as safe as humanly possible. There was no “rushing” to get their product out the door– it’s just that to write code for real time multitasking hardware, takes a lot of code complexity that can inadvertently cause unwanted or unexpected behavior sometimes. I’m talking about the Segway. The rare bug would ONLY occur when someone hit a bump, their feet left the platform, and the rider bounced twice quickly. This had the undesirable effect of telling the computers to instantly REVERSE both of the motors. The error was found only after this rare condition was linked to a few strange incidents that had been logged over the years. As soon as the company discovered the correlation… Read more »

This isn’t trolling. Loss of power in an automobile should never occur as a result of software error.

Multiple people must have screwed up quite badly for such basic functionality to cut out to stop working when the battery is still providing power.

Obviously you have had no exposure whatsoever to actually doing software coding. Once you get beyond a very simple program, it becomes impossible to absolutely guarantee there are no bugs.


Would you be so forgiving and defend GM if the Volt’s complex computer code caused it to experience sudden power loss?

It’s a bit far fetched to accuse kdawg of trolling for saying this is a serious bug in Tesla’s software. How exactly do you define trolling? And under your definition of trolling are you guilty of trolling the Volt in this forum?

Don’t over-simplify: 1. The Gen1 is not as code-complex as the Model S, so you can’t make a valid comparison. 2. KDawg is using this single case code glitch to judge the viability of a specific new vehicle, which does not yet exist: Model Three. Is that realistic or rational sounding to you? It does very much sound like drama-trolling, however. 3. KDawg apparently does NOT have personal experience with other EV’s that are also highly computer dependent to operate properly, that also exhibited unwanted behavior in unique conditions, after a protracted development cycle. His claims of “rushing” do not stand up to real world examples of similar software issues in similar EV products. 4. Companies that immediately notify consumers upon recognition of a software problem, advise users how to avoid said problem, who actively seek to correct, then distribute the correction– should not be held to higher imaginary / unrealistic standards, that other automakers (Like GM) have had caused multiple deaths due to defective physical engineering of their vehicles components. 5. Reality of GM killing their customers in the recent past, knowingly and then covering it up for over a decade, does not influence his interest in GM products… Read more »

How is the Volt not as “code-complex” as the Tesla 85D? The Volt has to control and blend two electric motors to deliver power, and also has to control an ICE motor to either generate electricity or power the wheels. It seems to me that the Volt is as code-complex or more code-complex as a Tesla 85D. What am I missing?

I am a software engineer and can appreciate how complex Model S is. But it’s one thing to release a mobile app or a website or whatever other software and then iron out any bugs as they are discovered. It’s a completely different thing to release software that controls 2 tons of metal going at 100 MPH.

I think kdawg’s point is valid. They shouldn’t have rushed this release before more extensive testing. (Which means they shouldn’t have promised end of January for torque sleep, which means they shouldn’t have claimed the improved range in October).

And yes, there are bugs that will not be discovered even with the most extensive testing, and that is a fact of life. But that case doesn’t look like one of them.

Well said.

s said:

“I am a software engineer and can appreciate how complex Model S is. But it’s one thing to release a mobile app or a website or whatever other software and then iron out any bugs as they are discovered. It’s a completely different thing to release software that controls 2 tons of metal going at 100 MPH.”

Seriously? As “a software engineer”, exactly what in the above article causes you to think this was a rushed release without significant testing?

I thought the story above about the Segway was an excellent real-world example of the sort of software bug which can remain hidden despite very thorough testing.

There’s a way to avoid software glitches in cars: Go back to cars, with no electronic controls. Of course, the Model T had its problems, too. Like the kickback that could break your arm when you were trying to start it with the hand crank. Sadly, Ford could not have issued an overnight, touchless fix for all Model T owners for -that- problem.

* * * * *

s continued:

“I think kdawg’s point is valid.”

I think kdwag is showing his usual pro-GM, anti-everybody-else bias.

Yeah, kdawg’s pro-GM, anti-everybody-else bias really shows in his comment just below this one where he says “I’m a fan of Tesla and will be seriously shopping the Model 3.” If that doesn’t show everyone how pro-GM and anti-everyone-else kdawg is, I don’t know what will.


I’m not trolling. I’m a fan of Tesla and will be seriously shopping the Model 3. However, this is a severe error in my book, and not one to just let it roll off our backs. Every car nowadays is very complex. The Volt has over 1 million lines of code, more than a fighter jet. But due diligence has to prevail over deadlines. I think you are sympathizing too much with Tesla on this one. If someone had died, this could have been a serious blow to EVs. We don’t need to give that crowd any more material. Tesla is lucky there are only 50K cars out there. If they were dealing with a million drivers, the statistics may have not been so good. (and they still may not be. Tesla needs to push the software to all the vehicles to disable this mode now. Not just advise drivers).

I agree that maybe more testing would benefit Tesla, but other automakers have these problems after tons of testing. Fortunately for Tesla, they have the ability to fix these things quickly, and at scale (unlike a recall). They shouldn’t use the capability as a crutch though.

I agree, this needs to be disabled on the affected vehicles immediately. Then push the fix out.

Come on. Tesla has always used owners as better testers not their programmers. It works unless u have another MS on the market (competition).
I love Tesla…but it’s like a “blue” steak….very tasty…but yet very raw.

Of course, it is absolutely NOT a “good thing.” OTOH, Tesla was quick and open to recognize and notify owners, and the temporary “fix” is easy and instant. As a P85D owner with .167 software, I will disable “range mode” this morning when I head out for some errands and wait for Tesla to get that bug fixed in the software.

I would be MUCH, MUCH more concerned if I were to discover this problem actually happening to me car and then find that Tesla had known about it but had not shared it with those of us in the field with their cars.

Congrats on the delivery. While I agree, and experienced a similar VW recall, for loss of power (search “flashing PRNDS”), I don’t think too much is to be made of the work around. By doing things OTA, and getting in front, this isn’t a big issue. VW took more than a dozen owner reportings, to NHTSA, before they stepped up.

Kudos Tesla

Software quality for mission-critical or safety related transportation applications must meet a higher standard than some desktop application.

It’s unacceptable for someone involved a fatal car, plane or train accident to hear “don’t worry, we’ll pick up that bug in some future release”.

What higher standard is there, than understanding the fact that what you code– can make or break the company overnight?

What higher standard is there, than to have your career decided by any potential bug (no matter how big or small) that could generate negative press about the product you’re working on?

What higher standard is there, than to know that what you code, can directly save or injure human lives?

What higher standard is there, than your own skills as a programmer, your experience, your judgement and your drive to create the best product out there?

If you want “a higher standard” beyond that, you’ll have to seek a 3rd party governmental group to establish standardization requirements on every automaker on the planet. Have fun with that.

“What higher standard is there, than. . .”

An Insane Mode standard. 😀

Actually we do have organisations that establish safety standards for many automobile components (tires, brakes, structure, even EV cabling….) and their successes have resulted in much safer vehicles with fewer deaths over the years.

Even Tesla won’t touch sensitive areas like friction braking technology, to the point of even using a vacuum pump to emulate an ICE engine for powering the conventional brake vacuum booster in the S and X.

You are directly comparing physical hardware to code. You do realize how apples to oranges that is, yes?

The fact that this is software related is irrelevant. It is unacceptable to have a car that puts occupants’ lives at risk due to design flaws. If your family member died as a consequence of this failure, you wouldn’t shrug your shoulders and “oh, software is hard…”. 25 years ago, I worked for GM as a co-op student at Delco electronics. I was chatting with one of the programmers of the engine controller firmware; at the time, I believe it was only a few kilobytes long and shared in common with in millions of cars. They hired an outside consulting firm for a million dollars just to look for errors in that code… They didn’t find any. But he caught something wrong before they went to production; it would have been enormously expensive to fix had it gone out the door, as it would’ve involved a physical recall. Of the millions of lines of code, not all of it is for mission critical functionality. If mission critical functionality is too complex to guarantee safe operation, that is, in itself, a design flaw. The fact that Tesla can push out updates automatically is both a good thing and a bad thing.… Read more »

High quality software isn’t about high stakes for the person writing the code, it’s about using development practices appropriate to the level of risk. There are many techniques that can be used to mitigate risk in a system whose failure would have catastrophic consequences. There are levels of redundancy and mathematically provable coding techniques which are expensive as hell but can be worth it when human lives are at stake.

Failing that, at least extensive testing should have uncovered a bug like this which seems to come about during normal operation of the vehicle. I love Tesla and what they are doing and will pick up the first one I can afford but seeing this article was a bit disappointing.

At least they did the right thing telling folk and will probably have it fixed lighting fast. Still can’t wait to join the ranks of Tesla owners in the future

Come on, this is serious and it is unacceptable. Some items should simply not fail, and power is one of them. This tells me that the Model S does not have a fail-safe architecture for at least this key function. It should. It’s a heck of a lot more important than adding valet mode or whatever they’ve worked on lately.

Don’t confuse testing for & fixing bugs, with prioritizing new features.

When one adds complexity to a system (like adding an additional motor), unforeseen interactions can (and usually do) occur. You’ve just multiplied the amount of control logic required to run the new hardware, especially since the given state of each motor can effect the other in real time.

If Tesla wasn’t doing a fantastic coding job, there would be far more issues with the latest firmware update, than this one drive train bug. A bug which is already isolated and the fix is likely in the testing phase.

I don’t care how many lines of code there are, this is a testing issue, tesla didn’t test the software enough before releasing it.

Still not that big of a deal. I think they should push software out to these cars disabling range mode, bntil a software fix is built and tested. This is a big tesla plus, that they can fix this without taking the car to a dealer which is a pita.

kdawg, you’re not being realistic. As cars — all cars, not just plug-in EVs — become more and more computerized, and as their software is called upon to do more and more complex tasks, this sort of thing will become more common… not less.

Tesla has more sophisticated software than other auto makers, but that doesn’t make them immune to the occasional bug. At least for Model S and future Tesla model owners, the fix will come overnight without the owner having to do anything about it.

How is Tesla more sophisticated than other automakers?

Is that a serious question?

Just look at the interior of the Model S. Note the Spartan lack of control buttons and knobs, as compared to any other luxury car. Almost everything is controlled via software rather than hardware.

Also, Tesla is the only company that does wireless updates of the car’s software. In most cases, there is no need to bring your car into a Tesla service center for an update.

That makes no inherent sense. The Model X and the Model 3 certainly won’t be using the same software and same builds as the Model S. Chances are this problem is already fixed. Tesla released a new build already. The model 3 could come along when there’s not a single known bug on the Model S and the Model 3 could still have bugs or could be bug free while the Model S has bugs.

In reality, they will probably both have bugs. It’s very unlikely to be one of this magnitude, and if the worst bug is one of this magnitude that affects few users and gets fixed in days, that’s not nearly as bad as the failures that most cars have had for the life of the auto industry. When bugs do come up, they are more likely to be along the scale of ones that keep album artwork from refreshing quickly when you listen to music, so even though things might not be bug free, it’s rare for any bug to affect actual driving.

“Power loss may leave you in a sticky situation, but what’s worse is that the vehicle’s regenerative brakes cut out when the power loss is experienced, meaning that some vehicles actually SPEED UP (until the brake pedal is depressed or power is regained) when the power loss issue kicks in.”

This makes absolutely no sense. Why would a Tesla speed up if it loses power and the regenerative brakes cut out? Unless it was on a very, very steep hill, wouldn’t a Tesla slow down if it loses power? Having the brakes also cut out wouldn’t make the Tesla go faster; it would just not slow down as fast as if the regenerative brakes worked.

I think this “brake issues” is due to sleep control of a motor. Therefore suddenly the regen is off. Sure you still get slower, without any pedal pressed, but only little without regen.

Example: You get close to a red light. Someone is in front of you and brakes slowly. You don’t need to brake, you start regen. But suddenly the regen is off and you start coasting. Until you react you already might have hit him…

Not nice and certainly affecting the safety.

Going downhill will cause acceleration, if regen suddenly turns off.

Physics ftw

The Volt does the same thing, when going over certain bumps and traction control engages. Regen turns off. No biggie.

I don’t think we humans can viscerally tell the difference between less deceleration, and acceleration.


Thanks for not responding to my comment and instead covertly editing the story to now read as follows: “some vehicles actually feel as though they speed up. . . .”

Tesla acknowledged its coding issue, why couldn’t you acknowledge your writing mistake?

Eric Loveday needs to get his facts check. Comparing this issue to the ford issue is plain wrong and could even be argued as libel. The Ford issue had to do with the ignition. In Ford’s power loss it was as if you turned the car off completely and took out the key. With Telsa, the engine loses power but everything else such as power steering, braking (not regen but regular of course), and perhaps most importantly the safety features like airbags are still fully functional. These are radically different issues and comparing them is very irresponsible if not illegal. Also the cars don’t speed up, they just don’t slow down like they normally do with the auto regen feature. This issue is caused by the torque sleep being implemented incorrectly. I figured that out without doing any research and simply confirmed it by doing research. I love the internet but it definitely has had a detrimental effect on the quality of “news articles”. I have seen blogs with more research and insight than this article.

Eric was referring to the Focus Electric SSN problem where the control software decided it didn’t like something and randomly shut off the power without warning. There are several anecdotes of it happening in the middle of intersections and freeway left lanes, which makes it potentially very dangerous.

Nothing to do with ignition, besides there isn’t an engine.

How is this any different than if your ICE car suddenly loses all power, say because the clutch goes, or gears fail, etc…? Perhaps all old cars should be scraped if they come with one of those unreliable ICEs. Now there’s an idea that would improve safety!

I’m sure Tesla will issue a fix as quickly as possible, after they have given it a good test of course, because they won’t want to make the situation any worse than it is already.

Woah, woah… YOU are the one libellously confusing issues… the GM issue (with non-electrified vehicles) was ignition related. The Ford Focus Electric “SSN” issue was NOT ignition related, and did NOT result in loss of power to steering, brakes, airbags or other safety systems. It only retracted power from the propulsion motor.

“Several dual-motor Model S owners with the most firmware 6.1, (with update .167) are experiencing sudden power loss while driving at speed.”

When everyone complains about why GM, Ford, etc. can’t do over the air updates like Tesla, this is why. Intentional changes can have unintentional consequences. This kind of stuff would be unacceptable for a large automaker, and lawsuits would abound.

Lawsuits abound when automakers ignore customers after the sale, and let design flaws kill their loved ones. How may people died from ignition switch issues in GM vehicles? I think the official count is now up to 53 innocent humans.

You’re right. I wouldn’t trust GM with wireless updates either, with a history like that.

Tesla on the other hand, has already isolated the issue, informed customers, and is likely already vetting a fix. They aren’t waiting for someone to die in their vehicles, and ignore the problem for a decade or more.

Absolutely. And what about Ford and the exploding Pinto?

Or more recently, Takata and the air bag fiasco?

You’re letting your bias cloud your judgment on many levels. I’m honestly not quite sure where to start.

But in an age where people can find anything on the internet that agrees with their own biases, and use that as “data” to back up their own opinions, I guess it is to be expected.

Since I don’t own a Model S, how ‘big’ of a driveability issue is this? Is ‘sudden power loss’ a 100% loss, or is it just a reduction to 25% of the former horsepower available?

If the latter, I wouldn’t consider it a huge safety issue, since 25% of 700 hp is still adequate.

You raise a good point Bill. Is the power loss worse than an BMW i3 REx trying to go up a big hill with a depleted battery? 😀

Ok, others have said 100%. So then it is similiar to the GM case where 57 deaths have been blamed to date.

I’m assuming the GM cars’ steering didn’t lock as you usually have to PULL the key to make the wheel lock. Turning to off just kills the power assist.

Interestingly, in my 2011 volt, sometimes the engine starts just before I get home. I say ‘NONONONo’ and hit the blue button twice, killing everything. I still have power steering for the next 20 seconds or so until I coast into the garage… Must be an accumulator holding the hydraulic assist.

My Roadster has non-assisted steering so there’s no loss issue. Never was there to begin with.

Of course, in a manual transmissioned GM car, the old mechanical steering pump would have to turn, even if ignition off. So those cars are inelligible for compensation, I’d assume.

Don’t drive it in Range Mode, and you don’t have to worry about it. 😛

It is sudden total power loss.

Of course, you won’t.

You have shown repeatly that you are a GM hater…

If GM had the same SW bug, you have would flamed GM repeatly for at least 10 times by now…

Doesn’t mean they can use this excuse to not provide infotainment updates.
I’d be wary of propulsion control updates OTA, but for non critical functions there’s no excuse to not offer the option.
If not OTA, at least a download option to manually install via USB.

True, and I think we’ll eventually get there. Right now though, the modules aren’t truly separate, and that complicates this idea.

As big a fan as I am, this is a pretty big QA screw-up.

OTA is a double-edged sword, but in the scheme of things, the benefits outweigh the risks, once of which is that we should see a fix shortly.

the biggest difference between Ford & Tesla here.
Ford took over a year to respond
Tesla took (conservatively) 5-10 days


How about the GM ignition key barrel problem?
It took a few deaths and years….

ignition key can be solved by NOT hanging all that junk on your key chain.

If you have a bare key, it wouldn’t just move on its own…

So, there is a work around, just like “don’t use the range option”.

Granted, one is HW, the other is SW….

I hope this knocks $100 off Tesla stock price. I wanna BUY BUY BUY


I thought everyone drove in “Insane” mode?!?!?!?

kdawg said:

“I’m not trolling. I’m a fan of Tesla and will be seriously shopping the Model 3. However, this is a severe error in my book, and not one to just let it roll off our backs. Every car nowadays is very complex. The Volt has over 1 million lines of code, more than a fighter jet. But due diligence has to prevail over deadlines.”

Well then, to be consistent kdawg, you’d better start recommending nobody ever buy a GM Volt.

To quote from one story:

“Yesterday, General Motors announced it will be running a ‘customer satisfaction program’ for some 4,000 2013 Chevrolet Volts to fix a software glitch that could cause the car’s electric motor to power down while driving.

“In other words, GM is asking all 2013 Chevy Volt owners to visit their local dealer to have a software update applied to their car in order to fix a software bug.”

Full story here:


From what’s reported in that article, it appears to be a very similar problem. Sadly, GM couldn’t wirelessly send updates to the affected cars, as Telsa can.

Nice try, Lensman, dropping in a report from Transport Evolve from 2 1/2 years ago without the context of time line in your joyfull lead-up.

Just 4,000 VIN’s of the 2013 Model Year Chevy Volt Extended Range Electric Vehicle were targeted in late 2013 for that Customer Satisfaction Program. This quick fix back then touched just 4% of near 100,000 total GM Voltec Platforms, Globally.

The time line and issuance date of a linked story is critical to be taken seriously on this forum and a few others.

Finally, again, with almost 100,000 GM Voltec Platforms built, essentially just in the last 40 months since Chevy Volt EREV ended limited US beta, only 4 Chevy Volt EREVs have been targed for an official NHTSA Safety Recall. (4 unique VIN’s) of the 2014 MY.

Impressive to say the least.


Thomas J. Thias

Sundance Chevrolet Inc.



Grins sheepishly
Edit- ‘Just 4,000 VIN’s of the 2013 Model Year Chevy Volt Extended Range Electric Vehicle were targered in late 2012 for that Customer Satisfaction Program.



Thomas J. Thias:

If you feel that I put that quote in starting with “Yesterday…” to make it seem this was a -recent- problem with the Volt, then I apologize. That wasn’t my intent; that’s how the article I quoted was written.

But personally, I don’t care if it was yesterday or five years ago. The -point- is that the Volt has already had almost precisely the same problem that’s now being reported for the Model S, yet our local GM apologist, kdawg, is trying to hold the Volt up as some sort of paragon of virtue in that regard.

As far as the cited Volt problem “only” affecting 4000 owners, I’ll bet money that many, many fewer than 4000 Model S owners have been affected by the bug in question! And yeah, I know there are more Volt owners than Model S owners. But not -that- many more.

I didn’t say “nobody buy Tesla”. I said it doesn’t help build my confidence in a startup company, that IMO, is still learning how to design/build cars.

I agree any type of power failure is a big issue, even in the Volts case. Just because it’s Tesla’s problem this time, they don’t get an automatic free pass.

FYI, I have received OTA updates on my Volt before. It was about 2 years ago, but I don’t recall what they did.

Seriously, GM can (sometimes) update the Volt’s software wirelessly? I didn’t know that; I didn’t even know the Volt had networked “connectivity” allowing GM wireless access to the car. Thanks for the correction!

While this will produce much “sturm und drang”, in the end Tesla will likely handle this and fix it in such a way to make all traditional car makers look slow and clunky in comparison.

For example, the BMW i3 has power loss problems, but still no fix, no 100% effective work-around, and fixes will likely require a dealer visit.

Meanwhile there is a 100% effective work around for P85D owners (there are no 85D owners yet, so zero units affected) and an OTA fix will likely come long before i3 owners even get told they can bring their cars to a dealership to get a fix.

Whiners will whine, but the actual owners will probably be perfectly happy with how it actually plays out in reality.

It’s a good thing that sudden power loss doesn’t happen while driving in Insane Mode. Can you imagine the internet outcry if a P85D experienced sudden power loss during a street race that was being video recorded, or worse yet during a drag strip rematch with the Challenger Hellcat?

Roll back the firmware and fix it or just OTA remove range mode option till fixed.

Yes, the unanswered question here (in my opinion) is why Tesla didn’t just “update” all the Model S’s to the previous software version, until they get the bug fixed. My guess — and it is just a guess — is either they think that not that many drivers will actually be affected, or else they think they can fix it quickly. When I look at the discussion regarding such problems with the Model S (like the “milling noise” problem that received so much attention a few months ago) on the Tesla Motors Club forum, I frequently see comments that thus-and-such service center didn’t even know about the problem until a customer brought it to their attention. So frankly, I get the impression that most of these problems, which get reported and repeated all over the Internet, are actually very rare, and the only reason they get much negative attention is that there are an awful lot of people out there with an axe to grind, who will gleefully report and repeat even the smallest problem Tesla has, either because they’re shorting TSLA stock or else they hate the company for political reasons. But then, it’s not really fair to complain… Read more »
“My guess — and it is just a guess — is either they think that not that many drivers will actually be affected, or else they think they can fix it quickly.” Seriously? You think that not rolling back the software version or disabling range mode OTA is justifiable because it’s relatively rare or will be quickly fixed, and is worth the risk of having someone die or get seriously injured from a sudden power loss. Just one preventable loss of life or serious injury will bring a firestorm, nay maelstrom, of bad news coverage and PR for Tesla that can’t be cured by a snarky Tweet from Elon. “I frequently see comments that thus-and-such service center didn’t even know about the problem until a customer brought it to their attention. So frankly, I get the impression that most of these problems, which get reported and repeated all over the Internet, are actually very rare” I frequently saw comments where the milling-noise problem was well known to thus-and-such service center. I even recall that one Model S owner had his milling-noise problem diagnosed over the phone as he drove his Tesla and service tech listened to the noise over the… Read more »

Here’s a third even more likely possibility for not “just” rolling back… the older software almost certainly had other unreported bugs that they don’t want the customers to “go back to”, so they’d rather move forward by releasing a next version with this now new needed fix rather than undoing the rest of the work. Pretty typical in software development. There’s always the one comment at the bottom of the release notes after all the new features that says something like “and other bug fixes”. That’s probably why they don’t want to just roll it back a version.

My Non-Tesla EV did this for a different reason, which is that the accelerator pedal failed while driving.

I was in the middle lane of a highway, keeping up with traffic, so rolling over 65, then I lost all power and almost got killed trying to get onto the emergency shoulder. Lots of helpful drivers for sure, NOT.

I raised hell with the car company and got it fixed immediately, but someone could have died because of this.

2 cents.

Won’t GO is bad.
Won’t STOP is worse!

Jr. Member
A: Concern: monthly latency service centers
« Reply # 62 on: Today at. 12:31 »
Called Tesla Oslo today due brakes that fail regularly. Was answered that I must put regeneration at low, this in order to wear the brake pads on slices ..? I run so hard that I should wear away this more than often enough ?? And one should not be able to regenerate in the winter? Is pretty scary when sailing down a hill without stopping power ..! And what will incidentally insurance say whether crashes car without brakes?
Moreover, I must get fixed charge hatch does not open with cable, rear window that does not go up and 20000 km service.
Result: hours June 15 : Omust say I was simply shocked! It’s simply too bad. Could get the drop on time if the brakes continues to fail but with a proviso that it could remain with them for 14 days ..?
Realize that it is not the employee’s fault but here should Tesla do something quickly to consistently queues .

All the commenters who are wailing that a car should never ever unexpectedly cut power are forgetting just how much power we are talking about here. Between the current and capacity contained in the high voltage battery, and the two monster torque motors, there is a TON of energy to be managed. Having the system cut out in the case of an unplanned condition is ABSOLUTELY the right thing, and a driver should ALWAYS be prepared to manage the vehicle safely to a shoulder. This is part of the RESPONSIBILITY of drivers for being in control of multiple tons of steel and other materials in motion, often at very high velocities! Yes, we as engineers are also responsible for minimizing (eliminating if possible) the cases where that could happen, but it is impossible to predict every one. Tesla have done the exact right thing… when the system misbehaves, withdrawing motor drive power (and keeping up power to safety systems brakes/steering/airbag etc.) is not only appropriate, it’s the safest thing to do. The next step is of course eliminating the condition that triggered the shutdown as soon as possible, but the shutdown itself is the correct reaction.